Covid-19: Do multiple boosters 'exhaust' our immune response? - Hindustan Times

Fourth doses of the COVID-19 vaccine don’t appear to offer significant protection against catching omicron according to a preliminary study conducted in Israel, the first country to authorize a second booster for its general population.

Marco Cavaleri, the European Medicines Agency's head of vaccines strategy, said at a news briefingthere’s no data supporting the broad effectiveness of fourth boosters.

Along with citing a lack of data on the effectiveness of multiple booster doses, Cavaleri said that frequent boosting could potentially have a negative impact on immune response to COVID-19, causing "fatigue in the population" that's received multiple shots.

Fortune said that although there is a scientific foundation for Cavaleri's concern, it should be interpreted as a question that researchers will be watching out for, rather than something they know about COVID-19 vaccines that should inform policy.

Stanford professor of immunology research Holden Maecker said in an email to DW he also hasn’t come across any science behind the idea that multiple boosters overwhelm the immune system, but mentioned data from the UK showing that delaying a second dose or boost until around six months is effective.

With that said, "we get yearly flu shots without detriment, and all indications so far suggest that occasional boosts for COVID-19 vaccines will be helpful," he wrote.

Paul Offit, Director of the Vaccine Education Center and an attending physician in the Division of Infectious Diseases at Children's Hospital of Philadelphia, has spoken critically against COVID-19 booster policies for the general population, calling the strategy misguided.

The COVID-19 vaccines have been held to an impossible standard, he said.

US health officials authorized booster doses in order to prevent mild illness, Offit said.

But the focus should instead be on administering first and second vaccine doses to people who are unvaccinated, rather than continuing to boost people who have already gotten their first two shots, he told DW.

I mean, when President Biden stood up on August 18 and said ‘we're going to have booster doses available for everybody over 16', I just don't know where that came from."

The CDC says that although two doses of the vaccine work to prevent severe illness in most people, boosters can help protect severe illness in people in risk groups, and against reinfection from new variants like omicron