10 things to know about the updated COVID vaccines

Experts from Yale University have answers for you about the newly updated COVID-19 vaccines.

There will be better protection against severe disease, hospitalization, and death from COVID-19 in the coming months now that newly updated (2023–2024 formula) mRNA COVID vaccines are available. The new shots are expected to keep more people from getting seriously ill with the virus through the winter, when infections and hospitalizations tend to tick upwards. And unlike the spring booster that targeted people ages 60 and older, these updated vaccines are for everyone ages 6 months and older.

The Food and Drug Administration (FDA) and the Centers for Disease Control and Prevention (CDC) approved the updated vaccines by Pfizer-BioNTech and Moderna in mid-September. (In early October, they also authorized an updated Novavax vaccine for use in individuals 12 and older; more on that below.)

The vaccines target XBB.1.5, a subvariant of Omicron that dominated the United States—and the world—from November 2021 until earlier this year. The CDC says the updated vaccines should also work against currently circulating variants of the SARS-CoV-2 virus—many of which descended from, or are related to, the XBB strain. This includes EG.5, the dominant strain in the US, and BA.2.86, a new subvariant sparking concern because it has more than 30 mutations to its spike protein.

While COVID-19 has been causing mostly mild illness recently, Yale Medicine infectious diseases specialist Onyema Ogbuagu reminds people that the disease can still lead to hospitalization and death.

“Infections can have long-term consequences,” Ogbuagu says, adding that even healthy people can develop Long COVID—a condition in which new, continuing, or recurring (and sometimes debilitating) symptoms are present four or more weeks after an initial coronavirus infection.

Here, Yale experts tell you what you need to know about the updated COVID vaccine: