How many years does it take to complete group immunization? What is the significance of group immunity?

Group immunity refers to the resistance of human or livestock groups to infection. The high level of group immunity means that the proportion of people who are resistant to infection is also high. Because the possibility of disease epidemic depends not only on the number of resistant individuals in the animal population, but also on the contact frequency between individuals in the animal population. Patrick, chief scientific adviser to the British government? Vallance once said that for the COVID-19 outbreak in Britain, Britain needs about 60% of the population to be infected with COVID-19, so as to get? Group immunity? . Vallance's remarks also caused a lot of controversy.

? Group immunity? It is a scientific concept in itself, that is, a large enough proportion of people can gain immunity to the disease through vaccine survival or recovery after infection, so as to prevent or block the further spread of the virus in the population and protect high-risk or vulnerable groups from infection. There is nothing wrong with the concept itself. But what about practice in reality? Group immunity? We must meet a series of necessary conditions, including many preconditions and risk elements.

First of all, the government adopting this strategy must effectively isolate the high-risk and vulnerable groups to ensure that the virus only affects the so-called low-risk groups, that is, health and young people. There is great doubt whether this can be done. Second, we must ensure that the virus remains stable and will not mutate. Third, we must ensure that? Group immunity? There will be no crowding out of medical resources in the practice process, thus ensuring that COVID-19 is in? Delay? In the process of strategy, it will spread steadily and other major diseases cannot break out, otherwise the demand for medical resources will be scarce, which will make? Group immunity? It can't really work. In fact, this is a gamble with many wishful thinking elements.

No vaccine? Group immunity? The risk is too great. This British-style anti-epidemic measure is basically contrary to the blockade and isolation measures currently adopted by China, Italy and other countries. The final result is still inconclusive. The advantage of this is that the loss is small, the impact on people's life, work and study is also small, and the economic loss caused by social lockout is small. Extra damage caused by strict blockade and isolation measures can be minimized. And the downside is to get what you want? Group immunity? In order to be effective, at least 60% people need to be exposed to the virus. However, COVID-19 is very cunning. It is constantly mutating, with high infectivity and mortality. As a result, under the group immunity, the fate of the British people will undoubtedly be miserable, and I am afraid that they will suffer several waves of virus bloodbath!