The FDA signed off on updated mRNA COVID-19 vaccines from Pfizer and Moderna. The new shots target the KP.2 strain and are expected to be available at pharmacies, hospitals and clinics within a few days, the drugmakers said.
The updated shots were approved for those 12 and older and received emergency use authorization for children ages 6 months through 11 years.
"Given waning immunity of the population from previous exposure to the virus and from prior vaccination, we strongly encourage those who are eligible to consider receiving an updated COVID-19 vaccine to provide better protection against currently circulating variants," Peter Marks, MD, PhD, director of the FDA's Center for Biologics Evaluation and Research, said in an Aug. 22 news release.
Clearance on the shots comes amid what experts anticipate will become the largest summer wave since the pandemic began. Virus levels measured in wastewater were "very high" nationally as of Aug. 16, according to the latest update from the CDC. Hospitalizations have been rising since May, though they remain far below levels seen in previous surges.
Three notes on the new vaccines:
Formula: The vaccines are formulated to target KP.2, an offshoot of the JN.1 omicron subvariant that dominated last winter. As of Aug. 17, KP.2 is estimated to account for about 3% of cases, while its sister strains — KP.3.1.1 and KP.3 — collectively account for 54% of cases. Since the dominating strains are closely related to KP.2, experts told NBC News they anticipate the vaccines will be effective at preventing severe disease.
The FDA instructed vaccine manufacturers to use the KP.2 strain for 2024-25 shot formulations in June, which was gaining traction at the time.
This marks the third time vaccines have been updated to better match circulating strains since they were first rolled out.
Who should get an updated vaccine: In June, the CDC recommended everyone 6 months and older receive an updated shot this fall. Anyone 5 and older is eligible to receive the new vaccines as long as it has been at least two months since they received their last dose.
Unvaccinated children between the ages of 6 months and 4 years may receive three doses of the updated Pfizer shot or two doses of the Moderna shot, while those who have been previously been vaccinated may receive one or two doses of the new shots, depending on the timing and number of doses they have received.
Per CDC guidance, people who have recently had COVID-19 "may consider delaying" their dose by three months, since infection provides some level of immunity. However, experts recommend people at high risk of severe disease get an updated vaccine when it is available, regardless of the timing of their last infection.
Coverage: The vaccines should be covered for most people with public and private health insurance.
Uninsured children are eligible to receive free vaccines through the federal Vaccines for Children Program.
Funding for the CDC's Bridge Access program, which provided free vaccines to uninsured adults, is set to expire at the end of August due to a lack of funding. Separately, certain community health centers and safety net providers that participate in a federal program may offer free vaccines to uninsured and underinsured adults.