What Coloradans should know about the new flu strain
Add Axios as your preferred source to
see more of our stories on Google.
Illustration: Eniola Odetunde/Axios
The current flu shot may not be as effective against a new virus strain that prompted an early start to this year's flu season, but local experts are still encouraging Coloradans to get the shot.
Why it matters: The new strain, a variant of H3N2, emerged over the summer, raising fears that the current flu vaccine might struggle to fight it.
Yes, but: Recent research suggests the existing flu shot is about 40% effective in preventing hospitalizations for adults with the new strain, state epidemiologist Rachel Herlihy tells us.
- It's roughly 70% effective for children, Herlihy adds.
How it works: The flu requires a new vaccine every year because the virus evolves to get around immunity, University of Colorado Anschutz School of Medicine assistant professor Jenna Guthmiller tells us.
- Guthmiller, an influenza immunity researcher, and Herlihy both say the vaccine is effective in preventing severe complications and hospitalization.
By the numbers: 24% of Coloradans received a flu shot so far this year, per state data.
State of play: While flu positivity rates rose last week, overall respiratory illness activity was low in Colorado, per the most recently available state data.
Context: The new version of H3N2 (subclade K) is a strain of influenza A.
- However, it is different from the H3N2 version used for the flu vaccine because the strain acquired seven different mutations over the summer after the reference strains had been chosen, experts said.
- Symptoms are similar to the common flu, including a sore throat, runny nose, fever, cough and headaches.
The bottom line: Herlihy recommends adults get the flu shot — local vaccination sites can be found online — alongside the latest COVID booster.
- "Any fighting chance against flu I think is a good thing," Guthmiller adds.