On 18 August 2021, Joe Biden, the president of the United States of America, announced that people who had received the Pfizer and Moderna vaccines for COVID-19 would need a third dose eight months after their second doses. He later updated it to a five-month gap between the second and third doses. Israel, one of the countries with the highest vaccination coverage, is now preparing for a fourth dose of vaccines for its population. Meanwhile, India has hastily approved a DNA vaccine without fully considering possible long-term consequences.
The world over, governments have hurriedly given emergency-use authorisation for COVID-19 vaccines, relying on the preliminary data of efficacy from phase III trials. The duration of protection offered by vaccines and the catalogue of serious adverse effects will be known only after two years, once all the data from the phase III trials is available. In India, we have gone one step further and have permitted the use of vaccines with no published phase III data. This is unnecessarily risky.
Biden’s decisions about the booster doses seem to have been announced in panic, even before the US Food and Drug Administration had evaluated the need for the extra dose. Ostensibly, this decision was taken to stymie the spread of the highly contagious Delta variant of the novel coronavirus. Rochelle Walensky, the director of the US Centers for Disease Control and Prevention, or CDC, was more forthcoming when she said in a press briefing that vaccine protection was waning. She said that data from Israel showed an increased risk of severe disease among those vaccinated early.