Marion Koopmans of a World Health Organization team arrives at the Hubei Center for Disease Control and Prevention in Wuhan in central China's Hubei province Monday, Feb. 1, 2021. The WHO mission team investigating the origins of the coronavirus pandemic in Wuhan. (AP Photo/Ng Han Guan)

Marion Koopmans of a World Health Organization team in a car arrives at the Hubei Center for Disease Control and Prevention in Wuhan in central China's Hubei province Monday, Feb. 1, 2021. The WHO mission team investigating the origins of the coronavirus pandemic in Wuhan. (AP Photo/Ng Han Guan)

Members of a World Health Organization team arrive at the Hubei Center for Disease Control and Prevention in Wuhan in central China's Hubei province Monday, Feb. 1, 2021. The WHO mission team investigating the origins of the coronavirus pandemic in Wuhan. (AP Photo/Ng Han Guan)

A worker in protective gear holds up a thermometer at the entrance to the Hubei Center for Disease Control and Prevention where a World Health Organization team is making a field visit in Wuhan in central China's Hubei province Monday, Feb. 1, 2021. The WHO mission team investigating the origins of the coronavirus pandemic in Wuhan. (AP Photo/Ng Han Guan)

Marion Koopmans of a World Health Organization team arrives at the Hubei Center for Disease Control and Prevention in Wuhan in central China's Hubei province Monday, Feb. 1, 2021. The WHO mission team investigating the origins of the coronavirus pandemic in Wuhan. (AP Photo/Ng Han Guan)

A worker in protective gear checks the temperature of a visitor at the entrance to the Hubei Center for Disease Control and Prevention where a World Health Organization team is making a field visit in Wuhan in central China's Hubei province Monday, Feb. 1, 2021. The WHO mission team investigating the origins of the coronavirus pandemic in Wuhan. (AP Photo/Ng Han Guan)

Security personnel hold back journalists at the entrance to the Hubei Center for Disease Control and Prevention where a World Health Organization team is making a field visit in Wuhan in central China's Hubei province on Monday, Feb. 1, 2021. The WHO mission team investigating the origins of the coronavirus pandemic in Wuhan. (AP Photo/Ng Han Guan)

A staffs clad in protective clothing checks WHO members' body temperature one by one at the entrance gate when vehicles enter Hubei Provincial Center For Disease Control and Prevention to investigate into an outbreak of the new coronavirus OVID-19 in Wuhan City, Hubei Province, China on February 1, 2021. Members of World Health Organization (WHO) probe team has been tackling to investigate into the origins of the new coronavirus COVID-19 pandemic. ( The Yomiuri Shimbun via AP Images )

Staffs clad in protective clothing check WHO members' body temperature one by one at the entrance gate when vehicles enter Hubei Provincial Center For Disease Control and Prevention to investigate into an outbreak of the new coronavirus OVID-19 in Wuhan City, Hubei Province, China on February 1, 2021. Members of World Health Organization (WHO) probe team has been tackling to investigate into the origins of the new coronavirus COVID-19 pandemic. ( The Yomiuri Shimbun via AP Images )

Staffs clad in protective clothing check WHO members' body temperature one by one at the entrance gate when vehicles enter Hubei Provincial Center For Disease Control and Prevention to investigate into an outbreak of the new coronavirus OVID-19 in Wuhan City, Hubei Province, China on February 1, 2021. Members of World Health Organization (WHO) probe team has been tackling to investigate into the origins of the new coronavirus COVID-19 pandemic. ( The Yomiuri Shimbun via AP Images )

Staffs clad in protective clothing check WHO members' body temperature one by one at the entrance gate when vehicles enter Hubei Provincial Center For Disease Control and Prevention to investigate into an outbreak of the new coronavirus OVID-19 in Wuhan City, Hubei Province, China on February 1, 2021. Members of World Health Organization (WHO) probe team has been tackling to investigate into the origins of the new coronavirus COVID-19 pandemic. ( The Yomiuri Shimbun via AP Images )

Staffs clad in protective clothing check WHO members' body temperature one by one at the entrance gate when vehicles enter Hubei Provincial Center For Disease Control and Prevention to investigate into an outbreak of the new coronavirus OVID-19 in Wuhan City, Hubei Province, China on February 1, 2021. Members of World Health Organization (WHO) probe team has been tackling to investigate into the origins of the new coronavirus COVID-19 pandemic. ( The Yomiuri Shimbun via AP Images )

Staffs clad in protective clothing check WHO members' body temperature one by one at the entrance gate when vehicles enter Hubei Provincial Center For Disease Control and Prevention to investigate into an outbreak of the new coronavirus OVID-19 in Wuhan City, Hubei Province, China on February 1, 2021. Members of World Health Organization (WHO) probe team has been tackling to investigate into the origins of the new coronavirus COVID-19 pandemic. ( The Yomiuri Shimbun via AP Images )

Peter Daszak of the World Health Organization leaves in a car past a row of security personnel at the Hubei Center for Disease Control and Prevention after a field visit in Wuhan in central China's Hubei province on Monday, Feb. 1, 2021. (AP Photo/Ng Han Guan)

Staffs clad in protective clothing check WHO members' body temperature one by one at the entrance gate when vehicles enter Hubei Provincial Center For Disease Control and Prevention to investigate into an outbreak of the new coronavirus OVID-19 in Wuhan City, Hubei Province, China on February 1, 2021. Members of World Health Organization (WHO) probe team has been tackling to investigate into the origins of the new coronavirus COVID-19 pandemic. ( The Yomiuri Shimbun via AP Images )

Staffs clad in protective clothing check WHO members' body temperature one by one at the entrance gate when vehicles enter Hubei Provincial Center For Disease Control and Prevention to investigate into an outbreak of the new coronavirus OVID-19 in Wuhan City, Hubei Province, China on February 1, 2021. Members of World Health Organization (WHO) probe team has been tackling to investigate into the origins of the new coronavirus COVID-19 pandemic. ( The Yomiuri Shimbun via AP Images )

Staffs clad in protective clothing check WHO members' body temperature one by one at the entrance gate when vehicles enter Hubei Provincial Center For Disease Control and Prevention to investigate into an outbreak of the new coronavirus OVID-19 in Wuhan City, Hubei Province, China on February 1, 2021. Members of World Health Organization (WHO) probe team has been tackling to investigate into the origins of the new coronavirus COVID-19 pandemic. ( The Yomiuri Shimbun via AP Images )

Peter Daszak of the World Health Organization leaves in a car from the Hubei Center for Disease Control and Prevention after a field visit in Wuhan in central China's Hubei province on Monday, Feb. 1, 2021. (AP Photo/Ng Han Guan)

Staffs clad in protective clothing check WHO members' body temperature one by one at the entrance gate when vehicles enter Hubei Provincial Center For Disease Control and Prevention to investigate into an outbreak of the new coronavirus OVID-19 in Wuhan City, Hubei Province, China on February 1, 2021. Members of World Health Organization (WHO) probe team has been tackling to investigate into the origins of the new coronavirus COVID-19 pandemic. ( The Yomiuri Shimbun via AP Images )

Staffs clad in protective clothing check WHO members' body temperature one by one at the entrance gate when vehicles enter Hubei Provincial Center For Disease Control and Prevention to investigate into an outbreak of the new coronavirus OVID-19 in Wuhan City, Hubei Province, China on February 1, 2021. Members of World Health Organization (WHO) probe team has been tackling to investigate into the origins of the new coronavirus COVID-19 pandemic. ( The Yomiuri Shimbun via AP Images )

Staffs clad in protective clothing check WHO members' body temperature one by one at the entrance gate when vehicles enter Hubei Provincial Center For Disease Control and Prevention to investigate into an outbreak of the new coronavirus OVID-19 in Wuhan City, Hubei Province, China on February 1, 2021. Members of World Health Organization (WHO) probe team has been tackling to investigate into the origins of the new coronavirus COVID-19 pandemic. ( The Yomiuri Shimbun via AP Images )

Staffs clad in protective clothing check WHO members' body temperature one by one at the entrance gate when vehicles enter Hubei Provincial Center For Disease Control and Prevention to investigate into an outbreak of the new coronavirus OVID-19 in Wuhan City, Hubei Province, China on February 1, 2021. Members of World Health Organization (WHO) probe team has been tackling to investigate into the origins of the new coronavirus COVID-19 pandemic. ( The Yomiuri Shimbun via AP Images )

Vehicles carrying members of World Health Organization (WHO) enter Hubei Provincial Center For Disease Control and Prevention to investigate into an outbreak of a potentially deadly lung virus, a new coronavirus OVID-19 in Wuhan, Hubei Province, China on February 1, 2021. Staffs clad in protective clothing check WHO members' body temperature one by one at the entrance gate. ( The Yomiuri Shimbun via AP Images )

Vehicles carrying members of World Health Organization (WHO) enter Hubei Provincial Center For Disease Control and Prevention to investigate into an outbreak of a potentially deadly lung virus, a new coronavirus OVID-19 in Wuhan, Hubei Province, China on February 1, 2021. Staffs clad in protective clothing check WHO members' body temperature one by one at the entrance gate. ( The Yomiuri Shimbun via AP Images )

Vehicles carrying members of World Health Organization (WHO) enter Hubei Provincial Center For Disease Control and Prevention to investigate into an outbreak of a potentially deadly lung virus, a new coronavirus OVID-19 in Wuhan, Hubei Province, China on February 1, 2021. Staffs clad in protective clothing check WHO members' body temperature one by one at the entrance gate. ( The Yomiuri Shimbun via AP Images )

A staffs clad in protective clothing checks WHO members' body temperature one by one at the entrance gate when vehicles enter Hubei Provincial Center For Disease Control and Prevention to investigate into an outbreak of the new coronavirus OVID-19 in Wuhan City, Hubei Province, China on February 1, 2021. Members of World Health Organization (WHO) probe team has been tackling to investigate into the origins of the new coronavirus COVID-19 pandemic. ( The Yomiuri Shimbun via AP Images )

Peter Daszak of the World Health Organization leaves in a car past a row of security personnel at the Hubei Center for Disease Control and Prevention after a field visit in Wuhan in central China's Hubei province on Monday, Feb. 1, 2021. (AP Photo/Ng Han Guan)

A staffs clad in protective clothing checks WHO members' body temperature one by one at the entrance gate when vehicles enter Hubei Provincial Center For Disease Control and Prevention to investigate into an outbreak of the new coronavirus OVID-19 in Wuhan City, Hubei Province, China on February 1, 2021. Members of World Health Organization (WHO) probe team has been tackling to investigate into the origins of the new coronavirus COVID-19 pandemic. ( The Yomiuri Shimbun via AP Images )

Vehicles carrying members of World Health Organization (WHO) enter Hubei Provincial Center For Disease Control and Prevention to investigate into an outbreak of a potentially deadly lung virus, a new coronavirus OVID-19 in Wuhan, Hubei Province, China on February 1, 2021. Staffs clad in protective clothing check WHO members' body temperature one by one at the entrance gate. ( The Yomiuri Shimbun via AP Images )

A staffs clad in protective clothing checks WHO members' body temperature one by one at the entrance gate when vehicles enter Hubei Provincial Center For Disease Control and Prevention to investigate into an outbreak of the new coronavirus OVID-19 in Wuhan City, Hubei Province, China on February 1, 2021. Members of World Health Organization (WHO) probe team has been tackling to investigate into the origins of the new coronavirus COVID-19 pandemic. ( The Yomiuri Shimbun via AP Images )

A van from the Hubei Center for Disease Control and Prevention enters the compound as the World Health Organization team makes a field visit in Wuhan in central China's Hubei province on Monday, Feb. 1, 2021. A World Health Organization team investigating the origins of the coronavirus pandemic visited a provincial disease control center that had an early hand in managing the outbreak. (AP Photo/Ng Han Guan)

A worker in protective overalls takes the temperature of a woman entering the Hubei Center for Disease Control and Prevention as the World Health Organization team makes a field visit in Wuhan in central China's Hubei province on Monday, Feb. 1, 2021. A World Health Organization team investigating the origins of the coronavirus pandemic visited a provincial disease control center that had an early hand in managing the outbreak. (AP Photo/Ng Han Guan)

A tired worker in protective overalls bends over to stretch at the entrance of the Hubei Center for Disease Control and Prevention as the World Health Organization team makes a field visit in Wuhan in central China's Hubei province on Monday, Feb. 1, 2021. (AP Photo/Ng Han Guan)

A man wears his mask at the entrance of the Hubei Center for Disease Control and Prevention enters the compound as the World Health Organization team makes a field visit in Wuhan in central China's Hubei province on Monday, Feb. 1, 2021. (AP Photo/Ng Han Guan)

Members of the World Health Organization team prepare to leave for a fourth day of field visits from their hotel in Wuhan in central China's Hubei province on Monday, Feb. 1, 2021. (AP Photo/Ng Han Guan)

From right, Dominic Dwyer and Peter Ben Embarek of the World Health Organization team prepare to leave for a fourth day of field visits from their hotel in Wuhan in central China's Hubei province on Monday, Feb. 1, 2021. (AP Photo/Ng Han Guan)

Members of the World Health Organization team including Peter Daszak, left, Ken Maeda, right, and Vladimir Dedkov, second right, prepare to leave for a fourth day of field visits from their hotel in Wuhan in central China's Hubei province on Monday, Feb. 1, 2021. (AP Photo/Ng Han Guan)

A worker in protective overalls adjusts his cap at the entrance of the Hubei Center for Disease Control and Prevention as the World Health Organization team makes a field visit in Wuhan in central China's Hubei province on Monday, Feb. 1, 2021. (AP Photo/Ng Han Guan)

Members of World Health Organization (WHO) leave a hotel to go to Hubei Provincial Center For Disease Control and Prevention to investigate into an outbreak of the new coronavirus OVID-19 in Wuhan City, Hubei Province, China on February 1, 2021. WHO probe team has been tackling to investigate into the origins of the new coronavirus COVID-19 pandemic. ( The Yomiuri Shimbun via AP Images )

Members of World Health Organization (WHO) leave a hotel to go to Hubei Provincial Center For Disease Control and Prevention to investigate into an outbreak of the new coronavirus OVID-19 in Wuhan City, Hubei Province, China on February 1, 2021. WHO probe team has been tackling to investigate into the origins of the new coronavirus COVID-19 pandemic. ( The Yomiuri Shimbun via AP Images )

Members of World Health Organization (WHO) leave a hotel to go to Hubei Provincial Center For Disease Control and Prevention to investigate into an outbreak of the new coronavirus OVID-19 in Wuhan City, Hubei Province, China on February 1, 2021. WHO probe team has been tackling to investigate into the origins of the new coronavirus COVID-19 pandemic. ( The Yomiuri Shimbun via AP Images )

A woman wearing a mask to protect from the coronavirus passes by a stone lion and Lunar New Year decorations outside a shop in Wuhan in central China's Hubei Province on Monday, Feb. 1, 2021. A World Health Organization team investigating the origins of the coronavirus pandemic is visiting the central Chinese city where the virus was first detected. (AP Photo/Ng Han Guan)

Indian laborers work on a flyover that is being reconstructed following technical snag in Kochi, Kerala state, India, Monday, Feb.1, 2021 India???s government plans to increase spending on health care in a budget that promises extra help for weathering the coronavirus pandemic. The budget proposal presented by the government on Monday also focuses on developing financial institutions and shoring up of infrastructure to get the pandemic-ravaged nation back on track as the world???s fastest-growing major economy. (AP Photo/R S Iyer)

A man wearing a mask as a precaution against the coronavirus rushes to board a bus in Kochi, Kerala state, India, Monday, Feb.1, 2021. India???s government plans to increase spending on health care in a budget that promises extra help for weathering the coronavirus pandemic. The budget proposal presented by the government on Monday also focuses on developing financial institutions and shoring up of infrastructure to get the pandemic-ravaged nation back on track as the world???s fastest-growing major economy. (AP Photo/R S Iyer)

Plainclothes security people keep journalists from approaching a convoy carrying the World Health Organization team during the field visit to the Wuhan Center for Disease Control and Prevention in Wuhan in central China's Hubei province on Monday, Feb. 1, 2021. (AP Photo/Ng Han Guan)

A worker wearing a mask, watches from inside a hospital across the Wuhan Center for Disease Control and Prevention after the World Health Organization team arrive to make a field visit in Wuhan in central China's Hubei province on Monday, Feb. 1, 2021. (AP Photo/Ng Han Guan)

Members of World Health Organization (WHO) arrive at a hotel after investgating Hubei Provincial Center For Disease Control and Prevention in Wuhan City, Hubei Province, China on February 1, 2021. WHO probe team has been tackling to investigate into the origins of the new coronavirus COVID-19 pandemic. ( The Yomiuri Shimbun via AP Images )

Members of World Health Organization (WHO) arrive at a hotel after investgating Hubei Provincial Center For Disease Control and Prevention in Wuhan City, Hubei Province, China on February 1, 2021. WHO probe team has been tackling to investigate into the origins of the new coronavirus COVID-19 pandemic. ( The Yomiuri Shimbun via AP Images )

Members of World Health Organization (WHO) arrive at a hotel after investgating Hubei Provincial Center For Disease Control and Prevention in Wuhan City, Hubei Province, China on February 1, 2021. WHO probe team has been tackling to investigate into the origins of the new coronavirus COVID-19 pandemic. ( The Yomiuri Shimbun via AP Images )

Members of World Health Organization (WHO) arrive at a hotel after investgating Hubei Provincial Center For Disease Control and Prevention in Wuhan City, Hubei Province, China on February 1, 2021. WHO probe team has been tackling to investigate into the origins of the new coronavirus COVID-19 pandemic. ( The Yomiuri Shimbun via AP Images )

Members of World Health Organization (WHO) arrive at a hotel after investgating Hubei Provincial Center For Disease Control and Prevention in Wuhan City, Hubei Province, China on February 1, 2021. WHO probe team has been tackling to investigate into the origins of the new coronavirus COVID-19 pandemic. ( The Yomiuri Shimbun via AP Images )

Staffs wearing face masks guard at the entrance gate while WHO members are investigating into an outbreak of the new coronavirus OVID-19 at Hubei Provincial Center For Disease Control and Prevention in Wuhan City, Hubei Province, China on February 1, 2021. Members of World Health Organization (WHO) probe team has been tackling to investigate into the origins of the new coronavirus COVID-19 pandemic. ( The Yomiuri Shimbun via AP Images )

Staffs wearing face masks guard at the entrance gate while WHO members are investigating into an outbreak of the new coronavirus OVID-19 at Hubei Provincial Center For Disease Control and Prevention in Wuhan City, Hubei Province, China on February 1, 2021. Members of World Health Organization (WHO) probe team has been tackling to investigate into the origins of the new coronavirus COVID-19 pandemic. ( The Yomiuri Shimbun via AP Images )

Staffs wearing face masks guard at the entrance gate while WHO members are investigating into an outbreak of the new coronavirus OVID-19 at Hubei Provincial Center For Disease Control and Prevention in Wuhan City, Hubei Province, China on February 1, 2021. Members of World Health Organization (WHO) probe team has been tackling to investigate into the origins of the new coronavirus COVID-19 pandemic. ( The Yomiuri Shimbun via AP Images )

Staffs wearing face masks guard at the entrance gate while WHO members are investigating into an outbreak of the new coronavirus OVID-19 at Hubei Provincial Center For Disease Control and Prevention in Wuhan City, Hubei Province, China on February 1, 2021. Members of World Health Organization (WHO) probe team has been tackling to investigate into the origins of the new coronavirus COVID-19 pandemic. ( The Yomiuri Shimbun via AP Images )

Security guards use barrier to close off the Wuhan Center for Disease Control and Prevention after the World Health Organization team arrive on a field visit in Wuhan in central China's Hubei province on Monday, Feb. 1, 2021. (AP Photo/Ng Han Guan)

Staffs wearing face masks guard at the entrance gate while WHO members are investigating into an outbreak of the new coronavirus OVID-19 at Hubei Provincial Center For Disease Control and Prevention in Wuhan City, Hubei Province, China on February 1, 2021. Members of World Health Organization (WHO) probe team has been tackling to investigate into the origins of the new coronavirus COVID-19 pandemic. ( The Yomiuri Shimbun via AP Images )

Staffs wearing face masks guard at the entrance gate while WHO members are investigating into an outbreak of the new coronavirus OVID-19 at Hubei Provincial Center For Disease Control and Prevention in Wuhan City, Hubei Province, China on February 1, 2021. Members of World Health Organization (WHO) probe team has been tackling to investigate into the origins of the new coronavirus COVID-19 pandemic. ( The Yomiuri Shimbun via AP Images )

Members of World Health Organization (WHO) arrive at a hotel after investgating Hubei Provincial Center For Disease Control and Prevention in Wuhan City, Hubei Province, China on February 1, 2021. WHO probe team has been tackling to investigate into the origins of the new coronavirus COVID-19 pandemic. ( The Yomiuri Shimbun via AP Images )

Plainclothes security personnel stand outside the Wuhan Center for Disease Control and Prevention before the World Health Organization team arrive to make a field visit in Wuhan in central China's Hubei province on Monday, Feb. 1, 2021. (AP Photo/Ng Han Guan)

A worker wearing a mask, watches from inside a hospital across the Wuhan Center for Disease Control and Prevention after the World Health Organization team arrive to make a field visit in Wuhan in central China's Hubei province on Monday, Feb. 1, 2021. (AP Photo/Ng Han Guan)

Plainclothes security personnel gather outside the Wuhan Center for Disease Control and Prevention after the World Health Organization team arrive to make a field visit in Wuhan in central China's Hubei province on Monday, Feb. 1, 2021. (AP Photo/Ng Han Guan)

A man pushes a person in a wheelchair who is wearing a mask and wool hat over the eyes is seen outside the Wuhan Center for Disease Control and Prevention during the World Health Organization team's field trip in Wuhan in central China's Hubei province on Monday, Feb. 1, 2021. (AP Photo/Ng Han Guan)

Security personnel holds hands to prevent journalists from getting close to the Wuhan Center for Disease Control and Prevention during the World Health Organization team's field trip in Wuhan in central China's Hubei province on Monday, Feb. 1, 2021. (AP Photo/Ng Han Guan)

A man rides an electric bike with two children outside the Wuhan Center for Disease Control and Prevention during the World Health Organization team's field trip in Wuhan in central China's Hubei province on Monday, Feb. 1, 2021. (AP Photo/Ng Han Guan)

A vehicle carrying members of the World Health Organization's team investigating the origins of the coronavirus pandemic leaves an infectious disease prevention center in Wuhan, China, on Feb. 1, 2021. (Kyodo via AP Images) ==Kyodo

A vehicle carrying members of the World Health Organization's team investigating the origins of the coronavirus pandemic enters an infectious disease prevention center in Wuhan, China, on Feb. 1, 2021. (Kyodo via AP Images) ==Kyodo

A vehicle carrying members of the World Health Organization's team investigating the origins of the coronavirus pandemic enters an infectious disease prevention center in Wuhan, China, on Feb. 1, 2021. (Kyodo via AP Images) ==Kyodo

A vehicle carrying members of the World Health Organization's team investigating the origins of the coronavirus pandemic enters an infectious disease prevention center in Wuhan, China, on Feb. 1, 2021. (Kyodo via AP Images) ==Kyodo

Members of the World Health Organization's team investigating the origins of the coronavirus pandemic arrive at an infectious disease prevention center in Wuhan, China, on Feb. 1, 2021. (Kyodo via AP Images) ==Kyodo

A photo shows Wuhan Center For Disease Control and Prevention where World Health Organization (WHO) are investigating into an outbreak of the new coronavirus OVID-19 in Wuhan City, Hubei Province, China on February 1, 2021. WHO probe team has been tackling to investigate into the origins of the new coronavirus COVID-19 pandemic. ( The Yomiuri Shimbun via AP Images )

A staff wearing face mask guards at the entrance gate while WHO members are investigating into an outbreak of the new coronavirus OVID-19 at Hubei Provincial Center For Disease Control and Prevention in Wuhan City, Hubei Province, China on February 1, 2021. Members of World Health Organization (WHO) probe team has been tackling to investigate into the origins of the new coronavirus COVID-19 pandemic. ( The Yomiuri Shimbun via AP Images )

A photo shows Wuhan Center For Disease Control and Prevention where World Health Organization (WHO) are investigating into an outbreak of the new coronavirus OVID-19 in Wuhan City, Hubei Province, China on February 1, 2021. WHO probe team has been tackling to investigate into the origins of the new coronavirus COVID-19 pandemic. ( The Yomiuri Shimbun via AP Images )

A photo shows Wuhan Center For Disease Control and Prevention where World Health Organization (WHO) are investigating into an outbreak of the new coronavirus OVID-19 in Wuhan City, Hubei Province, China on February 1, 2021. WHO probe team has been tackling to investigate into the origins of the new coronavirus COVID-19 pandemic. ( The Yomiuri Shimbun via AP Images )

A photo shows Wuhan Center For Disease Control and Prevention where World Health Organization (WHO) are investigating into an outbreak of the new coronavirus OVID-19 in Wuhan City, Hubei Province, China on February 1, 2021. WHO probe team has been tackling to investigate into the origins of the new coronavirus COVID-19 pandemic. ( The Yomiuri Shimbun via AP Images )

A photo shows Wuhan Center For Disease Control and Prevention where World Health Organization (WHO) are investigating into an outbreak of the new coronavirus OVID-19 in Wuhan City, Hubei Province, China on February 1, 2021. WHO probe team has been tackling to investigate into the origins of the new coronavirus COVID-19 pandemic. ( The Yomiuri Shimbun via AP Images )

A photo shows Wuhan Center For Disease Control and Prevention where World Health Organization (WHO) are investigating into an outbreak of the new coronavirus OVID-19 in Wuhan City, Hubei Province, China on February 1, 2021. WHO probe team has been tackling to investigate into the origins of the new coronavirus COVID-19 pandemic. ( The Yomiuri Shimbun via AP Images )

A photo shows Wuhan Center For Disease Control and Prevention where World Health Organization (WHO) are investigating into an outbreak of the new coronavirus OVID-19 in Wuhan City, Hubei Province, China on February 1, 2021. WHO probe team has been tackling to investigate into the origins of the new coronavirus COVID-19 pandemic. ( The Yomiuri Shimbun via AP Images )

A photo shows Wuhan Center For Disease Control and Prevention where World Health Organization (WHO) are investigating into an outbreak of the new coronavirus OVID-19 in Wuhan City, Hubei Province, China on February 1, 2021. WHO probe team has been tackling to investigate into the origins of the new coronavirus COVID-19 pandemic. ( The Yomiuri Shimbun via AP Images )

A photo shows Wuhan Center For Disease Control and Prevention where World Health Organization (WHO) are investigating into an outbreak of the new coronavirus OVID-19 in Wuhan City, Hubei Province, China on February 1, 2021. WHO probe team has been tackling to investigate into the origins of the new coronavirus COVID-19 pandemic. ( The Yomiuri Shimbun via AP Images )

A photo shows Wuhan Center For Disease Control and Prevention where World Health Organization (WHO) are investigating into an outbreak of the new coronavirus OVID-19 in Wuhan City, Hubei Province, China on February 1, 2021. WHO probe team has been tackling to investigate into the origins of the new coronavirus COVID-19 pandemic. ( The Yomiuri Shimbun via AP Images )

A photo shows Wuhan Center For Disease Control and Prevention where World Health Organization (WHO) are investigating into an outbreak of the new coronavirus OVID-19 in Wuhan City, Hubei Province, China on February 1, 2021. WHO probe team has been tackling to investigate into the origins of the new coronavirus COVID-19 pandemic. ( The Yomiuri Shimbun via AP Images )

A photo shows Wuhan Center For Disease Control and Prevention where World Health Organization (WHO) are investigating into an outbreak of the new coronavirus OVID-19 in Wuhan City, Hubei Province, China on February 1, 2021. WHO probe team has been tackling to investigate into the origins of the new coronavirus COVID-19 pandemic. ( The Yomiuri Shimbun via AP Images )

A photo shows Wuhan Center For Disease Control and Prevention where World Health Organization (WHO) are investigating into an outbreak of the new coronavirus OVID-19 in Wuhan City, Hubei Province, China on February 1, 2021. WHO probe team has been tackling to investigate into the origins of the new coronavirus COVID-19 pandemic. ( The Yomiuri Shimbun via AP Images )

A photo shows Wuhan Center For Disease Control and Prevention where World Health Organization (WHO) are investigating into an outbreak of the new coronavirus OVID-19 in Wuhan City, Hubei Province, China on February 1, 2021. WHO probe team has been tackling to investigate into the origins of the new coronavirus COVID-19 pandemic. ( The Yomiuri Shimbun via AP Images )

A photo shows Wuhan Center For Disease Control and Prevention where World Health Organization (WHO) are investigating into an outbreak of the new coronavirus OVID-19 in Wuhan City, Hubei Province, China on February 1, 2021. WHO probe team has been tackling to investigate into the origins of the new coronavirus COVID-19 pandemic. ( The Yomiuri Shimbun via AP Images )

A photo shows Wuhan Center For Disease Control and Prevention where World Health Organization (WHO) are investigating into an outbreak of the new coronavirus OVID-19 in Wuhan City, Hubei Province, China on February 1, 2021. WHO probe team has been tackling to investigate into the origins of the new coronavirus COVID-19 pandemic. ( The Yomiuri Shimbun via AP Images )

A photo shows Wuhan Center For Disease Control and Prevention where World Health Organization (WHO) are investigating into an outbreak of the new coronavirus OVID-19 in Wuhan City, Hubei Province, China on February 1, 2021. WHO probe team has been tackling to investigate into the origins of the new coronavirus COVID-19 pandemic. ( The Yomiuri Shimbun via AP Images )

A photo shows Wuhan Center For Disease Control and Prevention where World Health Organization (WHO) are investigating into an outbreak of the new coronavirus OVID-19 in Wuhan City, Hubei Province, China on February 1, 2021. WHO probe team has been tackling to investigate into the origins of the new coronavirus COVID-19 pandemic. ( The Yomiuri Shimbun via AP Images )

A photo shows Wuhan Center For Disease Control and Prevention where World Health Organization (WHO) are investigating into an outbreak of the new coronavirus OVID-19 in Wuhan City, Hubei Province, China on February 1, 2021. WHO probe team has been tackling to investigate into the origins of the new coronavirus COVID-19 pandemic. ( The Yomiuri Shimbun via AP Images )

A photo shows Wuhan Center For Disease Control and Prevention where World Health Organization (WHO) are investigating into an outbreak of the new coronavirus OVID-19 in Wuhan City, Hubei Province, China on February 1, 2021. WHO probe team has been tackling to investigate into the origins of the new coronavirus COVID-19 pandemic. ( The Yomiuri Shimbun via AP Images )

A photo shows Wuhan Center For Disease Control and Prevention where World Health Organization (WHO) are investigating into an outbreak of the new coronavirus OVID-19 in Wuhan City, Hubei Province, China on February 1, 2021. WHO probe team has been tackling to investigate into the origins of the new coronavirus COVID-19 pandemic. ( The Yomiuri Shimbun via AP Images )

A photo shows Wuhan Center For Disease Control and Prevention where World Health Organization (WHO) are investigating into an outbreak of the new coronavirus OVID-19 in Wuhan City, Hubei Province, China on February 1, 2021. WHO probe team has been tackling to investigate into the origins of the new coronavirus COVID-19 pandemic. ( The Yomiuri Shimbun via AP Images )

A vehicle carrying members of World Health Organization (WHO) leaves Hubei Provincial Center For Disease Control and Prevention to investigate in Wuhan City, Hubei Province, China on February 1, 2021. WHO probe team has been tackling to investigate into the origins of the new coronavirus COVID-19 pandemic. ( The Yomiuri Shimbun via AP Images )

A vehicle carrying members of World Health Organization (WHO) enters Hubei Provincial Center For Disease Control and Prevention to investigate in Wuhan City, Hubei Province, China on February 1, 2021. WHO probe team has been tackling to investigate into the origins of the new coronavirus COVID-19 pandemic. ( The Yomiuri Shimbun via AP Images )

A vehicle carrying members of World Health Organization (WHO) enters Hubei Provincial Center For Disease Control and Prevention to investigate in Wuhan City, Hubei Province, China on February 1, 2021. WHO probe team has been tackling to investigate into the origins of the new coronavirus COVID-19 pandemic. ( The Yomiuri Shimbun via AP Images )

A vehicle carrying members of World Health Organization (WHO) leaves Hubei Provincial Center For Disease Control and Prevention to investigate in Wuhan City, Hubei Province, China on February 1, 2021. WHO probe team has been tackling to investigate into the origins of the new coronavirus COVID-19 pandemic. ( The Yomiuri Shimbun via AP Images )

A vehicle carrying members of World Health Organization (WHO) leaves Hubei Provincial Center For Disease Control and Prevention to investigate in Wuhan City, Hubei Province, China on February 1, 2021. WHO probe team has been tackling to investigate into the origins of the new coronavirus COVID-19 pandemic. ( The Yomiuri Shimbun via AP Images )

Marion Koopmans, center, of the World Health Organization team, prepares to leave for a third day of field visit in Wuhan in central China's Hubei province on Sunday, Jan. 31, 2021. (AP Photo/Ng Han Guan), APTOPIX

Peter Daszak, center, of the World Health Organization team prepares to leave for a third day of field visit in Wuhan in central China's Hubei province on Sunday, Jan. 31, 2021. (AP Photo/Ng Han Guan)

Members of the World Health Organization team prepare to leave for a third day of field visit in Wuhan in central China's Hubei province on Sunday, Jan. 31, 2021. (AP Photo/Ng Han Guan)

Ken Maeda, center, of the World Health Organization team prepares to leave for a third day of field visit in Wuhan in central China's Hubei province on Sunday, Jan. 31, 2021. (AP Photo/Ng Han Guan)

A driver uses wet wipes to clean a vehicle as the World Health Organization team prepares to leave for a third day of field visit in Wuhan in central China's Hubei province on Sunday, Jan. 31, 2021. (AP Photo/Ng Han Guan)

Vladmir Dedkov, center, of the World Health Organization team prepares to leave for a third day of field visit in Wuhan in central China's Hubei province on Sunday, Jan. 31, 2021. (AP Photo/Ng Han Guan)

A security guard prevents journalists from following the World Health Organization team as they arrive at the Baishazhou wholesale market on the third day of field visit in Wuhan in central China's Hubei province on Sunday, Jan. 31, 2021. (AP Photo/Ng Han Guan)

Security personnel struggle with a journalist wearing a panda design covering at the Baishazhou wholesale market during a visit by the World Health Organization team on their third day of field visit in Wuhan in central China's Hubei province on Sunday, Jan. 31, 2021. (AP Photo/Ng Han Guan)

A plainclothes security person uses his umbrella to block journalists after the World Health Organization team arrive at the Baishazhou wholesale market on the third day of field visit in Wuhan in central China's Hubei province on Sunday, Jan. 31, 2021. (AP Photo/Ng Han Guan)

A plainclothes security person uses his umbrella to block journalists from filming after the World Health Organization team arrive at the Baishazhou wholesale market on the third day of field visit in Wuhan in central China's Hubei province on Sunday, Jan. 31, 2021. (AP Photo/Ng Han Guan)

Security personnel block journalists after the World Health Organization team arrive at the Baishazhou wholesale market on the third day of field visit in Wuhan in central China's Hubei province on Sunday, Jan. 31, 2021. (AP Photo/Ng Han Guan)

Security personnel use barriers to block the way after the World Health Organization team arrive at the Baishazhou wholesale market on the third day of field visit in Wuhan in central China's Hubei province on Sunday, Jan. 31, 2021. (AP Photo/Ng Han Guan)

Peter Ben Embarek of the World Health Organization team leaves in a convoy from the Baishazhou wholesale market on the third day of field visit in Wuhan in central China's Hubei province on Sunday, Jan. 31, 2021. (AP Photo/Ng Han Guan)

Peter Ben Embarek of the World Health Organization team passes by a Chinese police officer as he leaves in a convoy from the Baishazhou wholesale market on the third day of field visit in Wuhan in central China's Hubei province on Sunday, Jan. 31, 2021. (AP Photo/Ng Han Guan)

A worker in protective overall disinfects a vehicle from the World Health Organization convoy while they were visiting the Baishazhou wholesale market on the third day of field visit in Wuhan in central China's Hubei province on Sunday, Jan. 31, 2021. (AP Photo/Ng Han Guan)

A worker in protective overall passes by a warehouse at the Baishazhou wholesale market during a visit by the World Health Organization on the third day of field visit in Wuhan in central China's Hubei province on Sunday, Jan. 31, 2021. (AP Photo/Ng Han Guan)

A worker in protective overall disinfects a vehicle from the World Health Organization convoy while they were visiting the Baishazhou wholesale market on the third day of field visit in Wuhan in central China's Hubei province on Sunday, Jan. 31, 2021. (AP Photo/Ng Han Guan)

Members of World Health Organizaion (WHO) visit an imported seafood market to investigae into an outbreak of a potentially deadly lung virus, a new coronaviruus in Wuhan, Hubei Province, China on Jan.31, 2021. WHO probe team has continued tol tackle to probe into the origins of the Covid-19 pandemic. ( The Yomiuri Shimbun via AP Images )

Members of World Health Organizaion (WHO) visit an imported seafood market to investigae into an outbreak of a potentially deadly lung virus, a new coronaviruus in Wuhan, Hubei Province, China on Jan.31, 2021. WHO probe team has continued tol tackle to probe into the origins of the Covid-19 pandemic. ( The Yomiuri Shimbun via AP Images )

Members of World Health Organizaion (WHO) visit an imported seafood market to investigae into an outbreak of a potentially deadly lung virus, a new coronaviruus in Wuhan, Hubei Province, China on Jan.31, 2021. WHO probe team has continued tol tackle to probe into the origins of the Covid-19 pandemic. ( The Yomiuri Shimbun via AP Images )

A car in the World Health Organization convoy prepares to enter the Huanan Seafood Market on the third day of field visit in Wuhan in central China's Hubei province on Sunday, Jan. 31, 2021. Scientists initially suspected the coronavirus came from wild animals sold in the market. The market has since been largely ruled out but for the visiting WHO team of international researchers, it could still provide hints to how the virus spread so widely. (AP Photo/Ng Han Guan)

A convoy of cars carrying the World Health Organization team arrives at the Huanan Seafood Market on the third day of field visit in Wuhan in central China's Hubei province on Sunday, Jan. 31, 2021. Scientists initially suspected the coronavirus came from wild animals sold in the market. The market has since been largely ruled out but for the visiting WHO team of international researchers it could still provide hints to how the virus spread so widely. (AP Photo/Ng Han Guan)

A security guard waves for journalists to clear the road after a convoy carrying the World Health Organization team entered the Huanan Seafood Market on the third day of a field visit in Wuhan in central China's Hubei province on Sunday, Jan. 31, 2021. Scientists initially suspected the coronavirus came from wild animals sold in the market. The market has since been largely ruled out but for the visiting WHO team of international researchers it could still provide hints to how the virus spread so widely. (AP Photo/Ng Han Guan)

A photographer on a tall ladder tries to shoot photos of the World Health Organization convoy after it entered the the Huanan Seafood Market on the third day of a field visit in Wuhan in central China's Hubei province on Sunday, Jan. 31, 2021. Scientists initially suspected the coronavirus came from wild animals sold in the market. The market has since been largely ruled out but for the visiting WHO team of international researchers it could still provide hints to how the virus spread so widely. (AP Photo/Ng Han Guan)

A woman and a child wearing masks watch as journalists cover the arrival of the World Health Organization team at the Huanan Seafood Market on the third day of field visit in Wuhan in central China's Hubei province on Sunday, Jan. 31, 2021. Scientists initially suspected the coronavirus came from wild animals sold in the market. The market has since been largely ruled out but for the visiting WHO team of international researchers it could still provide hints to how the virus spread so widely. (AP Photo/Ng Han Guan)

A photographer on a tall ladder tries to shoot photos of the World Health Organization convoy after it entered the Huanan Seafood Market on the third day of field visit in Wuhan in central China's Hubei province on Sunday, Jan. 31, 2021. Scientists initially suspected the coronavirus came from wild animals sold in the market. The market has since been largely ruled out but for the visiting WHO team of international researchers it could still provide hints to how the virus spread so widely. (AP Photo/Ng Han Guan)

Security personnel remove a ladder used by a photographer trying to shoot into the Huanan Seafood Market during a visit by the World Health Organization team on the third day of field visit in Wuhan in central China's Hubei province on Sunday, Jan. 31, 2021. Scientists initially suspected the coronavirus came from wild animals sold in the market. The market has since been largely ruled out but for the visiting WHO team of international researchers it could still provide hints to how the virus spread so widely. (AP Photo/Ng Han Guan)

A convoy of vehicles carrying the World Health Organization team enters the interior of the Huanan Seafood Market on the third day of field visit in Wuhan in central China's Hubei province on Sunday, Jan. 31, 2021. Scientists initially suspected the coronavirus came from wild animals sold in the market. The market has since been largely ruled out but for the visiting WHO team of international researchers it could still provide hints to how the virus spread so widely. (AP Photo/Ng Han Guan)

A man looks out from a window that's part of the building for the Huanan Seafood Market as a World Health Organization team visits in Wuhan in central China's Hubei province on Sunday, Jan. 31, 2021. Scientists initially suspected the coronavirus came from wild animals sold in the market. The market has since been largely ruled out but for the visiting WHO team of international researchers it could still provide hints to how the virus spread so widely. (AP Photo/Ng Han Guan)

Plainclothes security personnel block a pedestrian crossing to prevent journalists from getting close to the Huanan Seafood Market during a visit by the World Health Organization team in Wuhan in central China's Hubei province on Sunday, Jan. 31, 2021. Scientists initially suspected the coronavirus came from wild animals sold in the market. The market has since been largely ruled out but for the visiting WHO team of international researchers it could still provide hints to how the virus spread so widely. (AP Photo/Ng Han Guan)