Lifespan of COVID antibodies will be known in few months, say experts

By Joymala Bagchi
New Delhi [India], July 16 : The lifespan of COVID-19 antibodies from infection as well as vaccines will only be known in the next few months, health experts said on Friday, adding that their longevity will depend on class and type.
There are different types of antibodies and all have different lifespans. It has been observed that several patients who had COVID-19 infection last year caught the virus again.
Antibodies such as IgM and IgG are broad groups and within these there are groups.
While speaking to ANI, Dr Arvind Kumar, Chairperson of the Institute of Chest Surgery, Chest Onco-Surgery and Lung Transplantation, Medanta Hospital said, "There are different types of antibodies and all have a lifespan. It's the class and type of antibodies which coronavirus or vaccination is producing belongs to a class which does not last than its stipulated time."
"We will have an answer in the next couple of months on whether they last more than six months or a year," he said.
An antibody is a protein produced by the body's immune system when it detects harmful substances, called antigens. Each type of antibody is unique and defends the body against one specific type of antigen.
It works by recognising and sticking to specific proteins, such as those found on the surfaces of viruses and bacteria, in a highly specific way. Speculations on booster dose after two doses is also not being overruled by the health experts.
"There has been talk about a booster dose being required to make the antibodies last longer, but this is speculation and maybe the final answer would be known in the next few months," Dr Kumar said.
What has been observed in COVID-19 was that many patients who had COVID last year and had become antibody positive once again tested COVID-19 positive this year as well. When tested, they were found to be negative as far as antibodies are concerned.
"It basically means whatever antibody they have got last year has vanished by this year as its lifespan is not over a year," said the doctor.
COVID-19 vaccinations started in India in mid-January. The maximum lifespan seems to be about five and a half months in India. In the United States, where vaccination started in mid-December, and in other countries, it is six and a half months.
"People who got COVID last year are getting reinfected may be primarily because antibodies are finished or due to some of the new mutations were not resistant," the doctor said while stressing the importance of serosurveys.