Third Booster Vaccine May Extend Duration of Immunity

Currently, all vaccines require two doses, two, three or four weeks apart, intramuscularly. However, a third booster shot or annual dose of vaccine like other flu shots can become normal and help immunity last longer.

“Studies on the durability of our immune responses to administered vaccines are currently underway. Emerging data suggests that there is a likelihood that our immunity will wane over time and given the increasing trend for the emergence of viral variants of concern, there is a high likelihood of booster doses, ”said Dr Veena. P. Menon, Ph.D, Faculty-Head, Laboratory of Clinical Virology, Amrita Institute of Medical Sciences, Kochi, at IANS.

“Yes, the third booster will help as new variants are emerging and we still don’t know how long the immunity lasts. Whatever immunity people get from vaccines, a booster will definitely help. also suggested annual vaccination, ”added Dr Suresh Kumar D., consultant, infectious disease specialist at Apollo Hospitals in Chennai.

However, it remains to be seen when it would be most appropriate to administer the third booster, Menon said.

Albert Bourla, CEO of US pharmaceutical company Pfizer, in a recent statement announced that recipients of the Covid vaccine will “likely” need a third dose between six and twelve months after their full vaccination. He also suggested the need for annual coronavirus vaccinations.

A booster is “a repeated dose of a vaccine you’ve already received to literally boost your immunity,” Susan R. Bailey, allergist and clinical immunologist and president of the American Medical Association, told National Geographic.

The third booster creates anti-virus memory in the immune system. Thus, it creates a “bigger and longer lasting immune response,” Bailey said.

But are the existing vaccines really capable of suppressing the new variants? Yes, say health experts.

“According to the WHO, all currently approved vaccines should provide at least some protection against the new variants, as protection is mediated by broad immune responses involving both arms of immunity – humoral (antibody dependent) and dependent. T cells, ”Menon said.

While the Pfizer and Moderna vaccines have shown a reasonable effect against the mutants, the South African and Brazilian mutants are of concern.

“Most of the current vaccines, including the Oxford-AstraZeneca vaccine, cover the UK variant well. But it performed poorly against the South African mutant. The efficacy is 10-15%, which is why South Africa Sud had to make the The vaccine is reasonably effective against the Brazilian variant with an effectiveness of around 40 to 50%. Covaxin has not been tested against these variants and there is no research on this yet ”, Kumar said.

“Changes or mutations in the virus cannot make vaccines totally ineffective. In the event that any of the current vaccines prove to be less effective against one or more variants, it will be possible to change the composition of the vaccines to protect themselves. against these variants, “Dr Alpana Razdan, vice president and head of laboratory, Genestrings Diagnostic Center, New Delhi, told IANS.

Vaccination is important and if it does not happen on time, the burden of Covid will stay longer, she noted.

While vaccines are not a shield against infection, they surely help reduce the severity of infection and the risk of death and hospitalization, experts said urging people to cut off the hesitation and to be safe. to inoculate.

(Rachel V. Thomas can be contacted at

rvt / vd