When is it a good time to take a booster shot: What the doctors are saying

New Delhi, Nov 27: With COVID-19 cases rising in many parts of the world, there are questions on whether it would be a good idea to roll out a booster shot. There are no clear answers and some doctors have said that there could be a downside to getting a booster shot against COVID-19 too soon.

A booster shot is given several months after the immune system has been prompted by an initial series. Usually two doses of the vaccine can investigate its response says Stanley Plotkin, vaccinologist and emeritus professor of pediatrics at the University of Pennsylvania in Philadelphia.

"That interval could be as short as four months, but generally speaking, a six-month interval is probably best," he also said. It was Plotkin's research that led to a vaccine for rubella more than 50 years back.

In an interview, he said that an even shorter interval, such as two months could compromise the body's ability to establish a durable immune response.

John Wherry, director of the institute for immunology at the university's Perelman School of Medicine says, that is because the immune system needs time to rejuvenate after making anti-bodies quickly and crudely to a new foe. As the emergency response dissipates the body works on making better anti-bodies that can be amplified rapidly when spurred by either another dose of the vaccine or a natural infection. A bit of rest seems to improve boostability, he also said.

Miles Davenport, head of the infection analytics program at the University of New South Wales' Kirby Institute in Sydney said that there is evidence to suggest that even greater intervals may be helpful.

Longer delays between doses of the AstraZeneca Plc shot and vaccinating COVID-19. Survivors at different time points show the peak immune system may come if a boost is given at least a year after the second dose.

When you get the third dose, I would say, is probably going to be dependent on how much virus is circulating. And if there's a lot of virus circulating, you're probably willing to compromise a little bit on your peak response in order to get the protection sooner, he also added.

"I don't know if it will be every year, but I doubt that it will be satisfactory just to let things go unless we are willing for the illnesses to continue at a high rate," the 89-year-old physician said. The poorer immune response to Covid vaccination and increased risk of dying from a SARS-CoV-2 infection among older people may necessitate a different immunization approach for them," Plotkin added.