In the middle of summer In response to a surge in COVID-19 infections, the U.S. Food and Drug Administration has approved an improved mRNA vaccine that more specifically targets currently circulating variants of the coronavirus.
The improved vaccines developed by Moderna and Pfizer/BioNTech target the Omicron variant known as KP.2, one of several so-called “FLiRT variants” that are causing the current COVID-19 outbreak. It will likely be several weeks before the new vaccines reach pharmacies and clinics.
“Given the waning immunity of the public from previous exposure to the virus and vaccination, we strongly encourage eligible individuals to consider getting the latest 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 regime aims to strengthen protection against COVID-19 hospitalizations and deaths. In 2023, more than 916,300 people were hospitalized with COVID-19 in the United States alone, and more than 75,500 died from the virus. Vaccination can also protect against long-COVID, a chronic illness that lasts at least three months after infection.
The U.S. Centers for Disease Control and Prevention is recommending that everyone 6 months of age or older get the new vaccine, regardless of whether they have previously received a COVID-19 vaccine.
Like the influenza virus, SARS-CoV-2 is constantly changing. Just as the influenza vaccine is updated annually to adapt to changes in the virus’ structure, so too is the COVID-19 vaccine. Elizabeth Hudson, regional director of infectious diseases at Kaiser Permanente Southern California, says SARS-CoV-2 is changing faster than the influenza virus, making it hard to predict which variants will dominate by the time a vaccine is available. “We’re seeing variants come in and out at a faster rate than influenza,” Hudson says.
The FDA’s go-ahead came after an advisory committee unanimously recommended in June that manufacturers develop improved versions of COVID-19 vaccines by this fall. Based on evidence at the time, FDA advisers initially recommended that new vaccines target a lineage called JN.1, a derivative of the Omicron strain. But the FDA updated its guidelines to ask vaccine makers to target the KP.2 strain, a descendant of the JN.1 variant that is closer to circulating variants.
The latest version of the COVID-19 vaccine was approved by the FDA on September 11, 2023. This formulation targeted XBB.1.5, the main variant circulating in the United States in early 2023. The virus has mutated significantly since then, and the currently circulating FLiRT variant is thought to be more transmissible and more effectively evades the immune system than previous versions of the virus.
If you’ve recently been infected with COVID-19, the CDC says you can consider delaying getting the vaccine for three months.
“For the most part, we’re recommending people get both the COVID vaccine and the flu vaccine in late September or October to get through the winter,” said Rosha McCoy, a pediatrician and senior director of medical affairs at the Association of American Medical Colleges. “Of course, people who are at higher risk or who are going to be in a higher-risk situation may want to get vaccinated earlier.”
Typically, the biggest surges of respiratory viruses occur in the winter, but COVID-19 tends to peak in both winter and summer, and the current summer surge is likely due to the emergence of new variants and the waning protection of previous vaccines.
“We’re at the lowest point in terms of natural and vaccine immunity since 2023,” Hudson said. “This is the worst case scenario for a more transmissible variant of COVID-19.”
