Universal Flu Vaccine Could Eliminate The Need For Annual Flu Shots

As flu season comes around in the fall, health professionals urge people to get their annual flu shots. Why do we get a flu vaccine every year? Like COVID, the flu virus changes. Scientists have to predict which strains of the flu are likely to become more active every flu season months in advance so that pharmaceutical companies have enough time to develop an updated vaccine. In some seasons the scientists' predictions are accurate, but in other seasons they can miss the mark. That's why you'll see deaths from the flu range from 12,000 to 52,000 in a given year, according to the Centers for Disease Control and Prevention.

Researchers are now looking at universal vaccines to eliminate the need for an annual vaccine, according to the National Institutes of Health. A Phase 1 clinical trial is recruiting 50 people aged 18 to 49 to test the safety of certain doses of the vaccine. Another group of people will receive a seasonal vaccine so the researchers can compare the effectiveness of the universal vaccine to the seasonal vaccine.

NIH says scientists use the hemagglutinin (HA) protein of the flu virus to develop flu vaccines. Typically, they use the head of this protein, which can quickly evolve each flu season. This universal vaccine uses the stem of the protein, which is more stable and evolves much more slowly. The vaccine also uses messenger RNA (mRNA) technology rather than a weakened part of the virus, per Medline Plus. mRNA technology was used to develop the Pfizer and Moderna COVID vaccines.

"A universal influenza vaccine would be a major public health achievement and could eliminate the need for both annual development of seasonal influenza vaccines, as well as the need for patients to get a flu shot each year," said Acting NIAID Director Hugh Auchincloss, M.D. in the NIH news release. "Moreover, some strains of influenza virus have significant pandemic potential. A universal flu vaccine could serve as an important line of defense against the spread of a future flu pandemic."

This universal vaccine isn't the first of its kind to be tested in clinical trials. A 2023 study in Science Translational Medicine found that a similar HA stem influenza vaccine was found to be safe and effective in a Phase 1 clinical trial. This vaccine lacks mRNA technology.