Have we achieved herd immunity against COVID?
With two years of pandemic, we have adjusted to the new normal. Washing hands frequently, wearing masks and maintaining social distance has become a habit now. However, the severity of COVID has been plunging recently and it has raised a celebratory chorus that we’ve finally achieved herd immunity. But, how true is that? 2 health experts explain if India has possibly attained herd immunity or not:
But, what exactly is herd immunity?
Before we talk about herd immunity against COVID 19 infection, it is important to understand what exactly it is. In a community, around 60 to 70% of the population is either vaccinated or has been infected by COVID and is carrying the antibody that protects the body against the infection. This is what we refer to as herd immunity and we can say that this is the major way we are able to eliminate or eradicate certain diseases.
Here’s what the expert says
Dr. Dibyendu Mukherjee, Consultant Internal Medicine, Fortis Hospital, Anandapur, Kolkata, says, “The COVID19 virus is relatively new as it’s been two and a half years since it’s been affecting people, so it would be difficult to conclude if India has attended herd immunity. People have been extensively vaccinated throughout the world, including India. So, India should attain herd immunity.”
But, is that really happening?
“As the strains are constantly mutating and changing their behaviour and new strains are coming, we cannot confirm whether there's herd immunity, as these strains and mutations are developing after the citizens were vaccinated. So, we are not sure if these vaccinations have developed an immunity that can fight the new strains or the new mutated strains of the virus.” adds Dr Mukherjee.
Virus mutations may prevent herd immunity
Dr. Ankita Baidya, Consultant - Infectious Diseases, HCMCT Manipal Hospitals, Dwarka, says, “When we talk about COVID, we first need to understand the nature of this virus as it keeps on mutating. It is very similar to the flu virus like Polio, in which every year one needs to get vaccination to keep it in control. The same thing applies in the case of COVID. As the virus keeps mutating and is able to evade the host’s immunity, the existing antibody (either through vaccination or natural infection) can diminish.”
Why is attaining herd immunity a challenge?
“The virus has an ability to recover in a person who has just recovered from this virus and has gained immunity. Therefore, Herd immunity is still a challenge for COVID virus as majority of the vaccines are targeting service protein, a common mutation area of this virus. Since this is the most common mutation part of the virus, the receptor or the outer protein of this virus keeps changing. So, the antibody may not be effective for the new strains. So Herd immunity is still a challenge for COVID but yes in terms of numbers, almost 60-70% or even more of the Indian population has developed some form of immunity. But given the changing nature of this virus and its mutations, achieving Herd immunity will be a challenge," says Dr Baidya.
Should we still take precautions?
Seeing the present infection rate, less severity of COVID patients and the complications from the infection has drastically come down, this might be due to the herd immunity we are developing. This might be because of the vaccinations, or the new strains are not that pathogenic. But we should continue following the precautions.