The European Medicines Agency (EMA) warned on Tuesday, 11 January, that frequent booster shots could have the opposite effect and weaken the immune system, reported Bloomberg.
Addressing a press briefing, the European Union (EU) regulator said that repeated booster shots may not be feasible and that countries should schedule booster shots as per the onset of the cold season in each hemisphere. In addition, the EMA advised nations to trace the guidelines set out by influenza vaccination strategies.
"Boosters can be done once, or maybe twice, but it's not something that we can think should be repeated constantly."Marco Cavaleri, the EMA head of biological health threats and vaccines strategy
The announcement comes in the backdrop of several countries considering the possibility of offering second booster shots to people for added protection against the surging Omicron infections.
Israel has already begun rolling out a second booster, or fourth shot, to those over 60 years of age.
However, the EMA clarified that oral and intravenous antivirals, such as Paxlovid and Remdesivir, maintain their efficacy against Omicron.
On 15 December, Prime Minister Narendra Modi announced that India would shortly begin administering COVID-19 booster shots for healthcare workers, frontline workers, and older adults.
(With inputs from Bloomberg.)