The FDA has now extended its emergency authorization of Pfizer and Moderna COVID-19 vaccines to include a second booster shot for all adults over 50.
Whilst announcing its decision, the FDA said that it had examined the evidence and that the known and potential benefits of a second booster outweigh the risks in this age group.
This updated guidance means additional boosters will be available from four months after the first booster dose, which is available for healthy adults and immunocompromised teenagers.
In light of this, the US Centers for Disease Control and Prevention has also updated the guidance on its vaccine pages in line with the FDA’s advice.
The agency now states: “Current evidence suggests some waning of protection over time against serious outcomes from COVID-19 in older and immunocompromised individuals.
Based on an analysis of emerging data, a second booster dose of either the Pfizer-BioNTech or Moderna COVID-19 vaccine could help increase protection levels for these higher-risk individuals.
Additionally, the data show that an initial booster dose is critical in helping to protect all adults from the potentially severe outcomes of COVID-19. So, those who have not received their initial booster dose are strongly encouraged to do so.”
This update means that anyone wanting a second booster in this age group should be allowed to get one but, at the moment, there is no official recommendation to do so.
It is agreed that a third dose strengthens immunity, but there’s still no clear consensus on whether a fourth dose does – although some scientists believe that fourth doses might be needed and that they offer a high degree of protection against hospitalization and death.
The FDA said that, when making its decision, it used data from Israel’s Ministry of Health on more than 700,000 people 18 and up who had received second boosters of the Pfizer-BioNTech vaccine at least four months after their first booster.
The agency said that it hadn’t seen any data that suggested any new safety concerns connected with a fourth dose and that it could provide additional immunity.