In the middle of a summer Amid rising Covid-19 infections, the US Food and Drug Administration has just approved updated mRNA vaccines that more closely target currently circulating coronavirus variants.
The updated vaccines, from Moderna and Pfizer/BioNTech, target an Omicron variant called KP.2, one of several so-called “FLiRT variants” that are collectively responsible for the current wave of COVID. The new vaccines will likely take a few weeks to reach pharmacies and doctors’ offices.
“Given the waning population immunity from prior exposure to the virus and prior vaccination, we strongly encourage those who are eligible to consider receiving an updated COVID-19 vaccine,” Peter Marks, director of the FDA’s Center for Biologics Evaluation and Research, said in a statement Thursday.
The new 2024-2025 formula aims to increase protection against hospitalization and death from Covid. In 2023, more than 916,300 people were hospitalized due to Covid-19 and more than 75,500 people died from the virus in the United States alone. Vaccination can also protect against long Covid, a chronic disease that lasts at least three months after an infection.
The U.S. Centers for Disease Control and Prevention recommends the new vaccine for All persons 6 months of age and olderregardless of whether or not they have previously received the Covid-19 vaccine.
Like the flu virus, SARS-CoV-2 is constantly changing. And similar to how flu vaccines are updated each year to accommodate the changing structure of the virus, COVID-19 vaccines are also being updated. Elizabeth Hudson, regional chief of infectious diseases at Kaiser Permanente Southern California, says SARS-CoV-2 is changing faster than the flu virus, making it difficult to predict which variants will be dominant when the vaccine comes out. “It’s changing variants more rapidly than what we’re seeing with the flu,” she says.
The FDA’s green light comes after an advisory committee in June unanimously recommended that manufacturers develop updated Covid vaccines by this fall. Based on the evidence at the time, FDA advisers initially recommended that new vaccines target a lineage called JN.1, an offshoot of Omicron. But the agency updated its guidecalling on vaccine makers to instead focus on the KP.2 strain, a descendant of the JN.1 variant, to more closely match circulating variants.
The latest version of the Covid vaccine was given the green light by the FDA on September 11, 2023. That formulation targeted the XBB.1.5 variant, the predominant one circulating in the US during the first half of 2023. The virus has mutated substantially since then, and the FLiRT variants currently circulating are thought to be more transmissible and evade the immune system more effectively than earlier versions of the virus.
If you’ve had a Covid-19 infection recently, the CDC says you may want to consider delay your vaccine dose for three months.
“Most of the time, we recommend getting COVID and flu vaccines more in late September or October, to try to get people through the winter months,” says Rosha McCoy, a pediatrician and senior director of health care affairs at the Association of American Medical Colleges. “Certainly if someone is at high risk or is going to be in a high-risk situation, they may want to get vaccinated sooner.”
Typically, the biggest surge in respiratory viruses occurs in the winter, but COVID tends to peak in both winter and summer, and the current summer surge is likely due to the emergence of new variants and waning protection from the previous vaccine.
“Natural immunity or vaccine immunity as of 2023 has hit a nadir,” Hudson says. “It’s kind of a perfect storm for a more infectious form of COVID-19.”