Pfizer requests assessment of efficiency of third dose of its vaccine

Representatives form pharmaceutical company Pfizer asked Brazil’s national drug regulator Anvisa for authorization to administer a third dose of vaccine Comirnaty in volunteers who received the first two doses of the inoculation at least six months ago.

As it stands today, Comirnaty’s package insert stipulates that each person should receive only two doses. The permit for a booster dose hinges on the approval of the Brazilian watchdog, tasked with certifying the security and efficiency of vaccines.

If the change is approved, the third dose may be administered in everyone aged 12 and older who received Comirnaty.

Pfizer’s inoculation against the novel coronavirus was the first to receive a definitive permit in Brazil, on February 23 this year. Until then, the agency had only given authorization for the emergency use of vaccines against the virus. That had been the case for Coronavac, produced by the Butantan Institute in partnership with China’s Sinovac, and for Astrazeneca, produced by the Oswaldo Cruz Foundation (Fiocruz) in partnership with the Oxford University and British laboratory Astrazeneca.

In a note, Anvisa reported it has 30 days to reply, provided no additional technical adjustments or clarifications are necessary. According to the agency, the clinical study Pfizer submitted to support its request included Brazilian as well as US and South African volunteers.