EXPLAINED: WHO says 'COVID-19 herd immunity will take time' | Here's what it is and how it can be achieved
New Delhi | Jagran Lifestyle Desk: The novel coronavirus, whose first case was reported in China’s Wuhan, continues to grow at an alarming rate in the country. Coronavirus, which is one of the most highly contagious viruses in the world, has affected over 13 lakh and claimed the lives of more than 30,000 in India so far.
With the virus continuing to grow at an alarming rate, researchers and scientists are trying their best to find a vaccine. However, they have failed to develop a vaccine that will be able to cure the deadly pathogen.
With the world failing to develop a vaccine for coronavirus, some researchers claimed that herd immunity could be the only way to save mankind from the coronavirus pandemic. However, the World Health Organisation (WHO) has dismissed the reports, saying "herd immunity" -- which is when enough people become resistant to a disease to stop its spread -- is still a long way ahead for COVID-19 since 50 to 60 per cent of the population will need to be immune to the novel coronavirus to protect the uninfected.
"That's much easier to do with a vaccine; we can achieve it faster and without people getting sick and dying. So, it is much better to do it that way, to achieve herd immunity through natural infection. We would have several waves [of infection] and unfortunately also the mortality that we see," news agency PTI quoted WHO's chief scientist, Dr Soumya Swaminathan, as saying.
"Over a period of time, people will start developing natural immunity. We know now from the studies that have been done in many of the affected countries that usually between 5 to 10 per cent of the population have developed antibodies. In some places, it's been higher than that, up to 20 per cent," she added.
So what is herd immunity exactly?
When a section of the population becomes immune to an infectious disease, making the spread of the disease from person to person unlikely, then it is known as ‘herd immunity’. Herd immunity is also known as “herd protection”.
How can we achieve herd immunity?
For diseases without a vaccine, the infection can still circulate among children and those with weakened immune systems even if some people have developed an immunity. According to Gypsyamber D’Souza and David Dowdy at the Bloomberg School, vaccines play an important role in developing herd immunity. Measles, mumps, polio, and chickenpox were some infectious diseases which were common earlier but are now rare as vaccines have helped develop herd immunity.
D’Souza and Dowdy also claim that some people who get infected by COVID-19 will be immune for months or years, but probably not their entire lives if the SARS-CoV-2 is similar to other coronaviruses.
What percentage of a community needs to be immune in order to achieve herd immunity?
As per researchers, that depends on disease to disease. If a disease is more contagious, then a larger portion of the population needs to be immune to control the spread of the infection. Meanwhile, researchers say that coronavirus is still evolving and could undergo several mutations and thus it is early to talk about permanent protection.
“It is very well possible that a person has antibodies against Covid-19 disease but no protection. These two are not the same thing, and therefore we need to be cautious when we interpret scientific findings in this manner,” Indian Express quoted Shahid Jameel, a virologist, as saying.
Posted By: Aalok Sensharma