U.S. — The FDA approved updated COVID-19 vaccines for the 2026-2027 season. The updated vaccines target the XFG strain.

Underlying conditions that increase the risk of severe COVID-19 include cancer, asthma, chronic lung disease, diabetes, heart conditions, mental health conditions, kidney disease, liver disease, obesity, and pregnancy. Vaccines are expected to be available in pharmacies, hospitals, and clinics across the U.S. in the coming days.

Like the influenza virus, the COVID virus mutates; it changes over time, and so we have to update the vaccine in our best attempt to match the strain that we anticipate will be most active during the coming winter, William Schaffner, professor of preventive medicine, said. "The better the match we have with what's in the vaccine and the circulating strain, the more effective the vaccine will be."

"We have to recognize that these vaccines work best at preventing severe disease. They work best at keeping us out of the hospital and intensive care unit," Schaffner said. Peter Chin-Hong, infectious diseases specialist, emphasized the importance of vaccination for specific groups.

"With those four populations, I'd put an exclamation point next to them. It's really important that we not lose sight of those four populations.. those are the people who I still see [most] in the hospital," Chin-Hong said.

It is safe to receive a COVID-19 vaccine at the same time as a flu shot or an RSV vaccine. "Both of those means of getting the vaccine and getting them simultaneously work just fine," Schaffner said. He noted concerns about delaying vaccination.

"Some people like to postpone it and just get one after the other. That will work, but I'm always worried that a vaccine postponed may be a vaccine never received," he said. Chin-Hong addressed insurance coverage. "I'm hopeful [insurers] will cover the vaccine because it makes sense for insurance companies to pay for it to prevent as many people from getting seriously ill," Chin-Hong said.

The XFG strain is a recombinant omicron variant formed through the combination of two omicron subvariants. The XFG strain accounted for about 40% of COVID-19 cases in the U.S. in July 2026, according to CDC data. More than 1.2 million Americans have died from COVID-19 since the pandemic began, according to the CDC. The CDC has not yet issued official recommendations for the 2026-2027 COVID-19 vaccines.

Why It Matters

The approval of updated vaccines targeting the XFG strain reflects the ongoing need to adapt to viral mutations. Health experts state that updating vaccines to match circulating strains is necessary due to this mutation. The XFG strain represented a portion of recent cases, accounting for about 40% of infections in July 2026. Vaccines remain most effective at preventing severe disease and hospitalization, making coverage crucial for high-risk and older populations.

The regulatory process involved advisory committee review earlier in the year. The FDA's Vaccines and Related Biological Products Advisory Committee voted 8 to 0, with one abstention, in May 2026 to recommend a monovalent XFG vaccine for the 2026-2027 season. This recommendation preceded the final FDA approval in August. The availability of multiple vaccine options from Moderna, Pfizer-BioNTech, and Novavax-Sanofi provides choices for different age groups and risk profiles.

Timeline

In March 2026, a federal judge stayed Health Secretary Robert F. Kennedy Jr.'s appointments to the CDC's Advisory Committee on Immunization Practices earlier in 2026.

The FDA approved updated COVID-19 vaccines for the 2026-2027 season on August 27, 2026. On the same date, Pfizer-BioNTech received FDA approval for its mRNA vaccine Comirnaty for individuals aged 65 and older, and for those aged 5 to 64 with underlying conditions. Also on August 27, 2026, Novavax and Sanofi received FDA approval for their protein-based vaccine Nuvaxovid for individuals aged 65 and older, and for those aged 12 to 64 with underlying conditions.

What's New

A study titled LP.8.1-directed COVID-19 mRNA vaccines durably boost neutralizing antibodies and mitigate ancestral immune imprinting was published in 2026 in PLoS Pathogens. In August 2026, Pfizer and BioNTech received U.S. FDA approval for their updated COMIRNATY COVID-19 vaccine targeting the XFG variant for high-risk individuals.

Moderna received FDA approval for its mRNA vaccine mNexspike for individuals aged 65 and older, and for those aged 12 to 64 with underlying conditions.