Three vials in a row, each with a bandage over it.
Illustration: PGN

What you need to know

  • For most Americans, being “fully vaccinated” is no longer sufficient when it comes to Omicron and its subvariants.
  • A COVID-19 booster shot increases effectiveness against hospitalization with Omicron from 57 to 90 percent.
  • Booster uptake remains low—only half of eligible Americans have gotten their extra shot.

Since Omicron entered the picture, evidence has increasingly suggested that being “fully vaccinated,” or receiving only the primary COVID-19 vaccine series, no longer provides sufficient protection against the virus. As a result, the CDC has shifted its guidance from “get vaccinated” to “stay up to date” with COVID-19 vaccines. Here’s why you need a COVID-19 booster.

What does it mean to “stay up to date”?

“Up to date” means a person has received all recommended COVID-19 vaccines, including any booster dose(s) when eligible. For everyone ages 12 and older, this means getting a booster shot. Adults ages 50 and older and people ages 12 and older who are immunocompromised are now also eligible to get a second booster. Anyone who got two doses of the Johnson & Johnson vaccine can also get a Pfizer or Moderna second booster.

Why are COVID-19 boosters important?

The CDC’s data shows that two mRNA doses are no longer sufficient in protecting against Omicron. After six months, the primary vaccine series becomes only 57 percent effective against hospitalization with Omicron.

But a booster shot increases protection significantly, bringing effectiveness against hospitalization with Omicron to 90 percent. The extra shot makes the biggest difference when it comes to protecting against infection and death among people ages 50 and older. This increased protection also appears to apply to the BA.2 Omicron subvariant.

What is the state of COVID-19 booster uptake in the country?

Despite all the evidence that confirms effectiveness, half of the booster-eligible population has not yet received a booster, including one-third of the 65 and older population. Staying up to date with COVID-19 vaccines will provide crucial protection, especially as new variants emerge.

How can we protect kids who aren’t eligible for a COVID-19 booster or a vaccine? 

Kids under 12 are not yet eligible to get a booster, and those under 5 cannot yet get vaccinated. As we wait for these options to become available, parents can increase protection for their kids by making sure the people around them are up to date on COVID-19 vaccinations.