With the end of summer approaching and young people across the United States returning to classrooms, revised COVID-19 vaccine formulations are expected to become available shortly. Regulators granted authorisation for revised vaccine formulations targeting the dominant circulating variant.
Moderna, Pfizer, and Sanofi all received regulatory authorisation for updated COVID-19 vaccines — the first two utilising mRNA technology, while Sanofi's offering uses a protein-based platform with a longer track record. Dr. William Schaffner, a preventive medicine professor at Vanderbilt University Medical Center in Nashville, explained that, like influenza, the COVID-19 virus undergoes notable mutation over time, requiring vaccine updates to align as closely as possible with the strain anticipated to be most prevalent in the coming winter months, and that a closer match between the vaccine formulation and the circulating strain generally produces a stronger protective response.
The reformulated 2026-2027 vaccines are directed at the XFG strain, a recombinant omicron variant that arose from the combination of two omicron subvariants. According to CDC figures released in July, XFG is responsible for roughly 40% of all reported cases nationwide.
The vaccine from Moderna has received authorisation for individuals between six months and 64 years of age who have a pre-existing health condition, as well as for everyone aged 65 and above. The vaccine manufactured by Pfizer has received authorisation for individuals between the ages of 5 and 64 who have a pre-existing health condition, as well as for all adults aged 65 and above.
The CDC identifies a range of health conditions that can elevate the risk of severe COVID-19 outcomes, including cancer, asthma, chronic lung disease, diabetes, heart disease, mental health disorders, and pregnancy, while health authorities note that vaccination remains most effective at reducing the likelihood of serious illness. Schaffner noted that the vaccines are most effective at preventing hospitalisation and admission to intensive care.
Updated COVID-19 vaccinations for the current season are anticipated to reach pharmacy, hospital, and clinic locations throughout the United States within the next few days. According to health professionals, administering a COVID-19 vaccination alongside a flu or RSV shot poses no safety concerns for those who meet the eligibility criteria. Schaffner explained that vaccines can be administered in separate arms or in the same arm at different points, and noted that receiving both at once or spacing them out are equally viable options, though some individuals prefer to get them on separate occasions.
Health professionals have noted that delayed vaccination schedules carry a possibility that postponed doses may never be administered. Separately, the CDC's Bridge Access Program, which provided free COVID-19 vaccines to uninsured adults and those without full vaccine coverage under their health plans, concluded in August 2024. Whether people without health insurance can obtain vaccines through state or local public health department immunisation programmes this season remains an open question.
Health officials anticipate that the revised COVID-19 vaccine will be available at no out-of-pocket expense under most insurance arrangements, among them Medicare Part B and Medicaid. Under federal rules, the majority of health insurers are required to provide coverage for vaccinations that the CDC's Advisory Committee on Immunization Practices endorses, a body that assesses and votes on how vaccines are deployed following regulatory approval or authorisation by the FDA.
Earlier this year, a federal judge placed a hold on Health Secretary Robert F. Kennedy Jr.'s appointments to the panel. Dr. Peter Chin-Hong, an infectious diseases specialist and associate dean for regional campuses at the University of California, San Francisco, told a news outlet that he anticipated insurers would choose to cover the vaccine, noting that reimbursing its cost to reduce the number of people who become severely ill represented a rational financial calculation for insurance providers.
Chin-Hong and Schaffner pointed out that even among those who have been vaccinated against COVID or contracted the virus in recent years, protective immunity tends to diminish over time. Immunisation has been shown to lower the likelihood of experiencing a serious health outcome, including admission to hospital or death. CDC data indicates that the virus has claimed over 1.2 million lives across the United States since the outbreak began.
Chin-Hong outlined four groups warranting priority vaccination with the updated COVID-19 shot — adults 65 and over, people with severely compromised immune systems, pregnant women, and infants and toddlers between six and 23 months of age — and stressed that keeping these populations at the forefront of vaccination efforts remains especially important. Chin-Hong added that the patient group continues to represent the majority of hospital admissions.
