Union health minister Mansukh Mandaviya has been urged to consider a second booster dose for Covid-19, especially for healthcare workers and frontline workers. The request reportedly came during a meeting between the health minister and the representatives of the Indian Medical Association (IMA) and other top doctors and public health experts.
Dr JA Jayalal, former president of the Indian Medical Association (IMA), who was part of the meeting with Mandaviya on Monday, said that the government was urged to consider a fourth dose for the population.
“The last dose for healthcare and frontline workers started nearly a year ago. Such a long gap would wane off immunity. We have urged the minister to consider a fourth precautionary dose for people, especially doctors, nurses, other hospital staff and frontline workers who have to manage patients and are at higher risk,” Dr Jayalal was quoted as saying by Hindustan Times.
Several countries — including Israel, Denmark, Hungary, and Chile — have authorized second booster shots of Covid-19 vaccine, but concerns were raised about whether this is a useful approach.
According to a Deutsche Welle article published in January, a study conducted in Israel suggested that fourth dose of the coronavirus vaccine does not offer significant protection from the Omicron variant.
In addition, the World Health Organization has suggested that blanket booster policies will increase inequity and prolong the pandemic by diverting vaccines toward countries with already-high levels of coverage, resulting in more opportunities for the virus to spread and mutate in less vaccinated countries.
Sarah Fortune, John LaPorte Given Professor of Immunology and Infectious Diseases and chair of the Department of Infectious Diseases at Harvard TH Chan School of Public Health, addressed another issue raised in the Deutsche Welle article — that frequent boosters might fatigue people’s immune systems.
She explained that when immune systems repeatedly see antigens such as those provided by vaccines, T cell “exhaustion” could result. However, she said that the science is more complicated in the case of Covid-19.
John Moore, a virologist at Weill Cornell Medicine in New York, however, said that older adults, immunocompromised people and pregnant women should get the booster shots, because they offer extra protection against severe disease and death.
In August, a modeling study by immunologists in Australia suggested that any booster at all would confer additional protection, but that a variant-specific shot was unlikely to be more effective than the original vaccine.
“The bulk of the benefit is from the provision of a booster dose, irrespective of whether it is a monovalent or bivalent vaccine,” the World Health Organization cautioned last month.
Studies have shown that most of the antibodies elicited by a vaccine targeting BA.5, for example, still recognize only the original virus.
That’s because of a phenomenon called “immune imprinting,” in which the body preferentially repeats its immune response to the first variant it encountered, despite being alerted to a newer variant.
“It’s easier for the immune system to go back to something that it has already seen,” said Florian Krammer, an immunologist at the Icahn School of Medicine at Mount Sinai in New York. (Dr. Krammer has served as a consultant for Pfizer.)
Some experts have suggested that the booster shots should have been “monovalent,” simply targeting the recent variants. Instead, the manufacturers effectively halved the crucial Omicron-specific component of the new booster, undermining the shot’s effectiveness, they said.
(With inputs from The New York Times)
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