Wearing a mask and social distancing are the two most reliable ways to reduce the spread of COVID-19, according to Prof. Ran Nir-Paz, Hadassah Medical Organization infectious disease expert, speaking at a webinar on COVID-19 on April 21. Countries such as China and Japan, where the wearing of masks has been commonplace for many years, have experienced better outcomes, he noted, than countries without that practice.
Contributing to the difficulty of preventing the spread of COVID-19 is the especially long duration of the virus in the body. "It takes a long time to get rid of the virus," Prof. Nir-Paz explained. Victims can be asymptomatic for up to 14 days, though the median is five days. Symptoms can last from a few days to about 12 days. But, Prof. Nir-Paz warned, "The total duration of time that a person can spread the virus is about 20 days from the onset of symptoms." He continued, "Generally, we don’t see that with other infectious viral diseases, though there are exceptions."
During his webinar, Prof. Nir-Paz listed some of the treatments being used on seriously ill COVID-19 patients. One of them is the Japanese drug Avigan, which Prof. Nir-Paz was instrumental in obtaining from the Japanese government. Others include hydroxychloroquine, Remdesivir, and convalescent plasma from recovered patients, none of which, he pointed out, has yet been proven to be an effective treatment for the disease. It will take some time, he warned, for a vaccine to be developed.
Despite the current emphasis on convalescent antibodies, Prof. Nir-Paz told his listeners that researchers have found no antibodies for the disease in about 30 percent of patients who survived COVID-19. This may indicate, he surmised, that these survivors have some other immunity to the disease. Finding out what their "active immunization" is will be tricky and will take time, he noted, but it's important to prevent the continuous spread of COVID-19 in the future.
As to the effect of warmth and sunlight on the virus, Prof. Nir-Paz pointed out that countries in the Southern Hemisphere, such as Brazil and Peru, and places on or near the equator, such as Singapore, are experiencing just as many cases as places in the Northern Hemisphere.