Is herd immunity possible?New Covid vairants can be a problem

When the coronavirus pandemic began to spread around the world in 2020, many governments and health authorities seemed to be looking forward to “herd immunity.”

In this approach, the virus spreads throughout society and not only causes infection, but also causes an immune response in those who have recovered.

If a sufficient number of people acquire these antibodies (for example, about 60-70% of the population), the infection of the virus will gradually decrease, and those who have not yet been infected will have less chance of spreading the virus. It is protected by becoming.

That was the theory.

In fact, Covid-19 struck Asia, Europe and the Americas, causing millions of infectious diseases, from which millions of people recovered, but also hundreds of thousands of hospitalizations and deaths. .. To date, the virus has caused over 164 million infections and 3.4 million deaths worldwide.

Strategies targeting herd immunity were quickly abandoned in most countries — With a few notable exceptions such as Sweden — And with the rapid development of vaccines, blockade has become a major way to prevent the spread of Covid.

We now have highly effective vaccines and vaccination programs are progressing rapidly around the world. This raised the hope that herd immunity could be achieved if a sufficient number of people in the population were vaccinated. That is, when enough people are vaccinated, the virus loses its place and disappears.

But, again, Covid-19 has proven to be unpredictable, and it is not yet known how long the innate immunity acquired by vaccine protection or previous infection will last.

Vaccine hesitation, the role of children in infection (infants are not eligible for vaccines), and most importantly, the emergence of new Covid variants worldwide are also unknowns that can interfere with herd immunity. Experts warn that there is.

Most of them believe that Covid-19 becomes endemic like the flu (that is, it means that it continues to circulate in some parts of the population as a seasonal threat), but it is dangerous over time. I want to be less sexual.

A year later, the coronavirus has some experience Significant mutation Many variants have also become dominant due to improved transmission rates, such as those first detected in the United Kingdom and South Africa last year.

Currently, the first subspecies detected in India in October 2020 is widespread throughout the country. Or later.. As with previous mutations, experts suggest that it is more contagious (early evidence suggests so) and more deadly (early evidence suggests not). We are investigating whether the Covid vaccine may be less effective (early evidence suggests it is not).

Professor Lawrence Young, a virologist at the University of Warwick School of Medicine in the United Kingdom, told CNBC that the pursuit of herd immunity was probably unattainable for Covid-19.

“Obviously the people of Sars-Cov-2 are ill, so pursuing herd immunity in terms of allowing people to recover from infection is not great, but the problem is herd immunity. Threshold and population percentage. Do you need to be protected? And it depends heavily on the transmission of the virus, “Young said.

“We are dealing with variants that have different ability to spread, which I think is why it makes it so difficult to achieve or actually rely on herd immunity.”

He emphasized that there are still many “unknowns” about Covid-19.

“And I think it will be impossible to try to get herd immunity by vaccination. That is the fact that after vaccination, the mutant and you do not always get the immune protection of life. Makes it more difficult, “Young said.

Asked if the coronavirus could be eradicated, Young said, “It won’t happen.”

“We need to live with it like the flu, and we need to vaccinate as many people as possible to prevent them from getting sick.”