A Food and Drug Administration (FDA) advisory panel voted on Friday against an additional, third booster shot of the COVID-19 vaccine from Pfizer-BioNTech. 

Both the Pfizer and Moderna drug companies have said a third booster shot is inevitable, but the question for the advisory panel was whether a booster shot for average Americans was needed now, about 10 months after they started rolling out.

Pfizer has argued that its data shows a booster shot is needed after six months of the initial dose; Moderna has argued that boosters for its vaccine should come after eight months and the White House had also been targeting an eighth month booster shot.

But the FDA panel ruled solely on the Pfizer-BioNTech booster shot, and rejected it. The panel considered data from Israel, showing that vaccine efficacy declines after six months. But there are differences in the way the US and Israel calculate COVID-19 illnesses, and the Israeli data also showed that the vaccine's protection against serious illness remains strong after six months.

Also up for debate has been the belief that more initial vaccine doses need to be distributed world-wide before the average, fully-vaccinated American gets a third, booster shot.

Still, a third booster shot will be rolling out across the US, starting on Monday, for people who are considered at higher-risk of catching COVID-19, and have compromised immune systems. The Centers for Disease Control and Prevention (CDC) will announce on Monday more guidance on where those doses will go.

Separately, the CDC announced on Friday that its finding show that Moderna's vaccine offers a better protection against hospitalization than the other widely-used vaccines. The CDC says the Moderna vaccine offers a protection rate of 93%, compared to a rate of 88% for the Pfizer-BioNTech vaccine, and 71% for the Johnson & Johnson vaccine./aa