Dikhyaa Mohanty 
The US Food and Drug Administration (FDA) has authorised boosters of the Pfizer or BioNTech and Moderna Covid-19 vaccines for all adults. The agency expanded emergency use authorisation for booster doses of both the mRNA vaccines beyond who was previously eligible — boosters had been authorised for anyone 65 years and older who has vaccinated with the Pfizer or Moderna vaccines at least six months ago and for certain adults at high risk of infection or of severe disease.
According to the reports, Pfizer and BioNTech requested authorisation last week based on the results of a Phase-3 trial involving more than 10,000 participants. It found boosters were safe and had an efficacy of 95 per cent against symptomatic Covid-19 compared with the two-dose vaccine schedule in the period when the highly transmissible Delta was the dominant strain.
Further Moderna requested authorisation of its 50-microgram booster dose for all adults on Wednesday. The company said the FDA based the emergency use authorisation (EUA) on the totality of scientific evidence shared by the company, including data that showed neutralizing antibodies had waned at about six months. The outside vaccine experts of the US Centers for Disease Control and Prevention (CDC) are scheduled to meet on Friday to discuss the FDA’s actions on the application from Pfizer-BioNTech and Moderna.
