TEL AVIV (VINnews) — Professor Yehoshua (Shuki) Shemer, the director of the Asuta association which runs hospitals in different regions in Israel and a former director-general of the Health Ministry, explained in an interview with Maariv how the coronavirus could affect society, whether a vaccine or antibodies will be found effective against it and whether a second wave is expected in the future.
Professor Shemer explained that the World Health Organization (WHO) declares a pandemic when the infection quotient is greater than 1, meaning that a disease is passing quickly from person to person. When there is no known vaccine one cannot control the number of people infected but one can control the rate of infection and thus ease the burden on the health system and this is what countries did by impelementing lockdowns, social distancing, isolation, masks etc.
The coronavirus progressed similarly in many countries, with the rise in numbers of people infected peaking after four to five weeks, a peak of about a week and then a fast regression. In most countries the graph of virus growth did not change according to the strategy used to curb it. Countries which placed significant restrictions like Israel, Italy and France had similar graphs to Sweden, South Korea and Taiwan which had less restrictions.
Regarding the question of whether a second wave is expected, Professor Shemer explained that this could only occur if the number of people infected had not created herd immunity, and this would only occur if 15-20% of the population had been infected according to worldwide data. Other members of the population have an automatic immunity to the virus having been exposed to similar types of virus. However a second wave could be caused by a new source of infection such as tourists, a crowd event with large numbers or a densely populated zone which does not maintain proper behavior.
The Health Ministry announced on May 6th that it would be conducting serological tests to locate antibodies on 100,000 citizens in an attempt to assess the level of infection in Israel and to make strategic preparations for a possible second wave in the winter.
Professor Shemer noted that in most countries which eased restrictions there was not a significant second wave at present but rather localized outbreaks or new sources of infection. In Singapore the second outbreak was due mainly to tourists. He added that the virus could disappear like SARS had done but this was unlikely. However the virus could mutate in a way which could ease its effects on people. Arizona researchers who investigated the genetic sequence of some infected people discovered a mutation which neutralized the ability of the virus to block the immune system from attacking it, and therefore a winter outbreak may not be as dangerous as the present one.
However Shemer was not optimistic about the possibility of a vaccine being ready and widely available by the winter, despite the fact that huge efforts are being invested to develop such a vaccine. The estimate is that an effective vaccine will take about a year to prepare and in the interim the Nes Tziona Biological Institute announced that they had identified an antibody which can bind the virus and prevent it reaching the upper respiratory tract. Professor Shemer said that was an important breakthrough this could enable the development of a medicine for critically ill patients and provide a form of immunity to medical staff. Some other medicines have proved effective against the virus, including plasma from patients who recovered,but these medicines are already in use for other diseases since developing a new medicine is a long process which can take years.
Regarding the question of how to act until a vaccine is found, Professor Shemer said that the three rules of hygiene, masks and social distancing in particular for those more susceptible to the virus and older people could help prevent new outbreaks at present or in the winter.