Letting Covid-19 spread to the point where there is no one left to infect is the principle of herd immunity. It is still necessary that infected people develop antibodies! According to a Chinese preliminary study, the news is not very good about this.
As the Covid-19 epidemic progresses, scientists are still quite divided. Some believe that recovered people are immune to disease thanks to their antibodies, at least for a while. Others believe that the risk of reinfection is very high. Yet the herd immunity strategy is currently being discussed in several countries – and had even been adopted in the UK just a month ago. By letting the virus infect a large part of the population , we then break the chains of contamination. In other words, there would be fewer and fewer hosts to infect and despite a large number of deaths, the others would in theory be immune.
On April 16, 2020, the Wall Street Journal relayed a preliminary Chinese study providing some answers on this strategy. The country wishing to resume its activity has just launched a national campaign to see more clearly about asymptomatic contamination and the level of immunity Population. Thus, thousands of people are currently undergoing serological tests. The goal? Prevent a potential second wave of Covid-19.
In Wuhan, home of the epidemic where the tests began, the leaders of the study have already noted two bad news. The first relates to the number of people tested who have developed antibodies. This one is simply too weak to hope for herd immunity . However, we are still talking about a city of 11 million inhabitants where thousands of asymptomatic cases can still be found!
In addition, Zhongnan Hospital – one of the largest in Wuhan – carried out tests on its own employees. However, only 2.4% of the 3,600 employees had developed antibodies. With regard to recent patients and other visitors (5,000 people), they would only be 2 to 3% in this case. This proves once again that herd immunity is far, very far from being achieved.
In other words, the only hope lies in the development of a vaccine, according to Wang Xinghuan director of Zhongnan Hospital. However, the first vaccines are not expected before 2021. Thus, the fear of a second wave of the epidemic is very present in China, especially considering the low number of cured people who have developed antibodies. In addition, Chinese researchers have admitted that they are not sure that having a positive antibody test ensures immunization!
