An operator wearing protective gear handles patients' samples at a laboratory of the Leumit Health Maintenance Organization Center for respiratory viruses in the central Israeli city of Or Yehuda on March 19, 2020. Israel added 244 news COVID-19 cases on Thursday, in the biggest single-day rise, making it the second worst-hit country in Mideast with its total number of infections rising to 677. (Photo by Gil Cohen Magen/Xinhua)

Operators wearing masks work at a laboratory of the Leumit Health Maintenance Organization Center for respiratory viruses in the central Israeli city of Or Yehuda on March 19, 2020. Israel added 244 news COVID-19 cases on Thursday, in the biggest single-day rise, making it the second worst-hit country in Mideast with its total number of infections rising to 677. (Photo by Gil Cohen Magen/Xinhua)

An operator wearing protective gear handles patients' samples at a laboratory of the Leumit Health Maintenance Organization Center for respiratory viruses in the central Israeli city of Or Yehuda on March 19, 2020. Israel added 244 news COVID-19 cases on Thursday, in the biggest single-day rise, making it the second worst-hit country in Mideast with its total number of infections rising to 677. (Photo by Gil Cohen Magen/Xinhua)

An operator wearing protective gear handles patients' samples at a laboratory of the Leumit Health Maintenance Organization Center for respiratory viruses in the central Israeli city of Or Yehuda on March 19, 2020. Israel added 244 news COVID-19 cases on Thursday, in the biggest single-day rise, making it the second worst-hit country in Mideast with its total number of infections rising to 677. (Photo by Gil Cohen Magen/Xinhua)

An operator wearing mask works at a laboratory of the Leumit Health Maintenance Organization Center for respiratory viruses in the central Israeli city of Or Yehuda on March 19, 2020. Israel added 244 news COVID-19 cases on Thursday, in the biggest single-day rise, making it the second worst-hit country in Mideast with its total number of infections rising to 677. (Photo by Gil Cohen Magen/Xinhua)

An operator wearing mask works at a laboratory of the Leumit Health Maintenance Organization Center for respiratory viruses in the central Israeli city of Or Yehuda on March 19, 2020. Israel added 244 news COVID-19 cases on Thursday, in the biggest single-day rise, making it the second worst-hit country in Mideast with its total number of infections rising to 677. (Photo by Gil Cohen Magen/Xinhua)

An operator wearing protective gear handles patients' samples at a laboratory of the Leumit Health Maintenance Organization Center for respiratory viruses in the central Israeli city of Or Yehuda on March 19, 2020. Israel added 244 news COVID-19 cases on Thursday, in the biggest single-day rise, making it the second worst-hit country in Mideast with its total number of infections rising to 677. (Photo by Gil Cohen Magen/Xinhua)

An operator wearing mask works at a laboratory of the Leumit Health Maintenance Organization Center for respiratory viruses in the central Israeli city of Or Yehuda on March 19, 2020. Israel added 244 news COVID-19 cases on Thursday, in the biggest single-day rise, making it the second worst-hit country in Mideast with its total number of infections rising to 677. (Photo by Gil Cohen Magen/Xinhua)

An operator wearing protective gear handles patients' samples at a laboratory of the Leumit Health Maintenance Organization Center for respiratory viruses in the central Israeli city of Or Yehuda on March 19, 2020. Israel added 244 news COVID-19 cases on Thursday, in the biggest single-day rise, making it the second worst-hit country in Mideast with its total number of infections rising to 677. (Photo by Gil Cohen Magen/Xinhua)

An operator wearing mask works at a laboratory of the Leumit Health Maintenance Organization Center for respiratory viruses in the central Israeli city of Or Yehuda on March 19, 2020. Israel added 244 news COVID-19 cases on Thursday, in the biggest single-day rise, making it the second worst-hit country in Mideast with its total number of infections rising to 677. (Photo by Gil Cohen Magen/Xinhua)

An operator wearing protective gear handles patients' samples at a laboratory of the Leumit Health Maintenance Organization Center for respiratory viruses in the central Israeli city of Or Yehuda on March 19, 2020. Israel added 244 news COVID-19 cases on Thursday, in the biggest single-day rise, making it the second worst-hit country in Mideast with its total number of infections rising to 677. (Photo by Gil Cohen Magen/Xinhua)

An operator wearing protective gear handles patients' samples at a laboratory of the Leumit Health Maintenance Organization Center for respiratory viruses in the central Israeli city of Or Yehuda on March 19, 2020. Israel added 244 news COVID-19 cases on Thursday, in the biggest single-day rise, making it the second worst-hit country in Mideast with its total number of infections rising to 677. (Photo by Gil Cohen Magen/Xinhua)

An operator wearing protective gear handles patients' samples at a laboratory of the Leumit Health Maintenance Organization Center for respiratory viruses in the central Israeli city of Or Yehuda on March 19, 2020. Israel added 244 news COVID-19 cases on Thursday, in the biggest single-day rise, making it the second worst-hit country in Mideast with its total number of infections rising to 677. (Photo by Gil Cohen Magen/Xinhua)