OSTRAVA, CZECH REPUBLIC - APRIL 11: The students watches an instructional video on how the antigen test is performed as first to fifth grades return to elementary schools across the country in Ostrava, Czech Republic on April 11, 2021. The Czech government closed all schools due to the COVID-19 pandemic since 01 March 2021. Pupils must be tested by antigen tests for COVID-19 two times a week. Lukas Kabon / Anadolu Agency/ABACAPRESS.COM

OSTRAVA, CZECH REPUBLIC - APRIL 11: A teacher helps a child how to perform an antigen test as first to fifth grades return to elementary schools across the country in Ostrava, Czech Republic on April 11, 2021. The Czech government closed all schools due to the COVID-19 pandemic since 01 March 2021. Pupils must be tested by antigen tests for COVID-19 two times a week. Lukas Kabon / Anadolu Agency/ABACAPRESS.COM

OSTRAVA, CZECH REPUBLIC - APRIL 11: The parent is preparing an antigen test as first to fifth grades return to elementary schools across the country in Ostrava, Czech Republic on April 11, 2021. The Czech government closed all schools due to the COVID-19 pandemic since 01 March 2021. Pupils must be tested by antigen tests for COVID-19 two times a week. Lukas Kabon / Anadolu Agency/ABACAPRESS.COM

OSTRAVA, CZECH REPUBLIC - APRIL 11: School briefcase in front of the classroom as first to fifth grades return to elementary schools across the country in Ostrava, Czech Republic on April 11, 2021. The Czech government closed all schools due to the COVID-19 pandemic since 01 March 2021. Pupils must be tested by antigen tests for COVID-19 two times a week. Lukas Kabon / Anadolu Agency/ABACAPRESS.COM

OSTRAVA, CZECH REPUBLIC - APRIL 11: Students before entering primary school, where they are waiting for testing for COVID as first to fifth grades return to elementary schools across the country in Ostrava, Czech Republic on April 11, 2021. The Czech government closed all schools due to the COVID-19 pandemic since 01 March 2021. Pupils must be tested by antigen tests for COVID-19 two times a week. Lukas Kabon / Anadolu Agency/ABACAPRESS.COM

OSTRAVA, CZECH REPUBLIC - APRIL 11: A student performs himself antigen test as first to fifth grades return to elementary schools across the country in Ostrava, Czech Republic on April 11, 2021. The Czech government closed all schools due to the COVID-19 pandemic since 01 March 2021. Pupils must be tested by antigen tests for COVID-19 two times a week. Lukas Kabon / Anadolu Agency/ABACAPRESS.COM

OSTRAVA, CZECH REPUBLIC - APRIL 11: A student performs himself antigen test as first to fifth grades return to elementary schools across the country in Ostrava, Czech Republic on April 11, 2021. The Czech government closed all schools due to the COVID-19 pandemic since 01 March 2021. Pupils must be tested by antigen tests for COVID-19 two times a week. Lukas Kabon / Anadolu Agency/ABACAPRESS.COM

OSTRAVA, CZECH REPUBLIC - APRIL 11: The students watches an instructional video on how the antigen test is performed as first to fifth grades return to elementary schools across the country in Ostrava, Czech Republic on April 11, 2021. The Czech government closed all schools due to the COVID-19 pandemic since 01 March 2021. Pupils must be tested by antigen tests for COVID-19 two times a week. Lukas Kabon / Anadolu Agency/ABACAPRESS.COM

OSTRAVA, CZECH REPUBLIC - APRIL 11: The parent is preparing an antigen test as first to fifth grades return to elementary schools across the country in Ostrava, Czech Republic on April 11, 2021. The Czech government closed all schools due to the COVID-19 pandemic since 01 March 2021. Pupils must be tested by antigen tests for COVID-19 two times a week. Lukas Kabon / Anadolu Agency/ABACAPRESS.COM

OSTRAVA, CZECH REPUBLIC - APRIL 11: A parent helps to a girl perform antigen test as first to fifth grades return to elementary schools across the country in Ostrava, Czech Republic on April 11, 2021. The Czech government closed all schools due to the COVID-19 pandemic since 01 March 2021. Pupils must be tested by antigen tests for COVID-19 two times a week. Lukas Kabon / Anadolu Agency/ABACAPRESS.COM

OSTRAVA, CZECH REPUBLIC - APRIL 11: A student performs himself antigen test as first to fifth grades return to elementary schools across the country in Ostrava, Czech Republic on April 11, 2021. The Czech government closed all schools due to the COVID-19 pandemic since 01 March 2021. Pupils must be tested by antigen tests for COVID-19 two times a week. Lukas Kabon / Anadolu Agency/ABACAPRESS.COM

OSTRAVA, CZECH REPUBLIC - APRIL 11: The student is preparing an antigen test as first to fifth grades return to elementary schools across the country in Ostrava, Czech Republic on April 11, 2021. The Czech government closed all schools due to the COVID-19 pandemic since 01 March 2021. Pupils must be tested by antigen tests for COVID-19 two times a week. Lukas Kabon / Anadolu Agency/ABACAPRESS.COM

OSTRAVA, CZECH REPUBLIC - APRIL 11: A parent helps to a boy perform antigen test as first to fifth grades return to elementary schools across the country in Ostrava, Czech Republic on April 11, 2021. The Czech government closed all schools due to the COVID-19 pandemic since 01 March 2021. Pupils must be tested by antigen tests for COVID-19 two times a week. Lukas Kabon / Anadolu Agency/ABACAPRESS.COM

OSTRAVA, CZECH REPUBLIC - APRIL 11: The student unpacks the test stick as first to fifth grades return to elementary schools across the country in Ostrava, Czech Republic on April 11, 2021. The Czech government closed all schools due to the COVID-19 pandemic since 01 March 2021. Pupils must be tested by antigen tests for COVID-19 two times a week. Lukas Kabon / Anadolu Agency/ABACAPRESS.COM

OSTRAVA, CZECH REPUBLIC - APRIL 11: The student is waiting for the evaluation of the antigen test as first to fifth grades return to elementary schools across the country in Ostrava, Czech Republic on April 11, 2021. The Czech government closed all schools due to the COVID-19 pandemic since 01 March 2021. Pupils must be tested by antigen tests for COVID-19 two times a week. Lukas Kabon / Anadolu Agency/ABACAPRESS.COM

OSTRAVA, CZECH REPUBLIC - APRIL 11: The student is preparing an antigen test as first to fifth grades return to elementary schools across the country in Ostrava, Czech Republic on April 11, 2021. The Czech government closed all schools due to the COVID-19 pandemic since 01 March 2021. Pupils must be tested by antigen tests for COVID-19 two times a week. Lukas Kabon / Anadolu Agency/ABACAPRESS.COM

OSTRAVA, CZECH REPUBLIC - APRIL 11: A teacher helps a child how to perform an antigen test as first to fifth grades return to elementary schools across the country in Ostrava, Czech Republic on April 11, 2021. The Czech government closed all schools due to the COVID-19 pandemic since 01 March 2021. Pupils must be tested by antigen tests for COVID-19 two times a week. Lukas Kabon / Anadolu Agency/ABACAPRESS.COM

OSTRAVA, CZECH REPUBLIC - APRIL 11: The parent is preparing an antigen test as first to fifth grades return to elementary schools across the country in Ostrava, Czech Republic on April 11, 2021. The Czech government closed all schools due to the COVID-19 pandemic since 01 March 2021. Pupils must be tested by antigen tests for COVID-19 two times a week. Lukas Kabon / Anadolu Agency/ABACAPRESS.COM

OSTRAVA, CZECH REPUBLIC - APRIL 11: The student is preparing an antigen test as first to fifth grades return to elementary schools across the country in Ostrava, Czech Republic on April 11, 2021. The Czech government closed all schools due to the COVID-19 pandemic since 01 March 2021. Pupils must be tested by antigen tests for COVID-19 two times a week. Lukas Kabon / Anadolu Agency/ABACAPRESS.COM

OSTRAVA, CZECH REPUBLIC - APRIL 11: Used antigen tests in the trash as first to fifth grades return to elementary schools across the country in Ostrava, Czech Republic on April 11, 2021. The Czech government closed all schools due to the COVID-19 pandemic since 01 March 2021. Pupils must be tested by antigen tests for COVID-19 two times a week. Lukas Kabon / Anadolu Agency/ABACAPRESS.COM

OSTRAVA, CZECH REPUBLIC - APRIL 11: The student disinfects her hands before entering school as first to fifth grades return to elementary schools across the country in Ostrava, Czech Republic on April 11, 2021. The Czech government closed all schools due to the COVID-19 pandemic since 01 March 2021. Pupils must be tested by antigen tests for COVID-19 two times a week. Lukas Kabon / Anadolu Agency/ABACAPRESS.COM

OSTRAVA, CZECH REPUBLIC - APRIL 11: A student performs himself antigen test as first to fifth grades return to elementary schools across the country in Ostrava, Czech Republic on April 11, 2021. The Czech government closed all schools due to the COVID-19 pandemic since 01 March 2021. Pupils must be tested by antigen tests for COVID-19 two times a week. Lukas Kabon / Anadolu Agency/ABACAPRESS.COM