Image: Sarah Grillo/Axios
The majority of US adults — including most American seniors — are heading into the holiday season and anticipate a spike in cases without the maximum level of immunization against the virus.
Driving the news: Only 36% of American seniors — and just 16% of the general population ages 18 and older — received the updated booster shot that became available in September.
Why it matters: Vaccines become less effective over time, which means that even vaccinated people who have not had a vaccine in a while may not be well protected from serious infections.
The big picture: All the data that has come out in the last two years says the vaccines are effective. The problem is twofold: effectiveness changed as the virus evolved, and it also wanes if you haven’t had your last shot for a while.
- The lesson is that the vaccines are working, a booster shot is important — especially for older, vulnerable people — and people who haven’t had a vaccination recently are at significantly higher risk than if they had.
- The effectiveness of vaccines against serious illness and death lasts longer than protection against contracting the virus, but is still declining significantly.
- COVID hospitalizations are currently on the rise, particularly among seniors, reflecting at least in part the lackluster uptake of booster shots.
Driving the news: Recent CDC data have quantified the value of updated booster shots directed against both the original virus strain and the Omicron variant.
- Two studies published earlier this month showed a mixed picture of the vaccine’s effectiveness against hospitalization. One found that the updated vaccination was 57% effective against hospitalization compared to no vaccination.
- Compared to receiving the last dose five to seven months ago, the updated vaccine was 38% more effective at preventing hospitalization, the study found. However, if it was 11 months or more since the last dose, the updated vaccine was 45% more effective.
The second study found greater effectiveness in adults aged 65 and over. Compared to unvaccinated individuals, the updated vaccine was 84% effective against hospital admissions.
- Compared to people who received only two or more doses of the original syringe, the updated syringe was 73% effective.
- The relative effectiveness of the vaccine is hampered by the fact that so many Americans — including unvaccinated people — have already been infected with COVID, meaning they may have some natural immunity.
Yes but: The shots are much less effective at preventing routine infections, and some scientists say the value of the booster shot may be more limited in younger populations, who are generally not at risk for severe cases anyway.
- “There’s a world of difference between what happens to younger healthy people and what happens to older, sicker people,” said Cornell virologist John Moore Booster.
Zoom in: Many Americans don’t believe they need the updated recordings.
- In a recent KFF survey, 44% of vaccinated respondents who had not received an updated booster dose said they did not need it, including nearly two-thirds of Republican or Republican-leaning respondents.
- Another 37% said they didn’t think the benefit was worth it.
Between the lines: A recent UK Health Agency report, which focused on older Omicron variants, found that six to eight months after receiving a second dose of the Pfizer or Moderna vaccine, protection from hospitalization and mortality compared to unvaccinated individuals decreased to around 50% was down.
- This contrasts with an effectiveness of about 80% in the first three months after the injection.
- People who received a third dose of either vaccine did slightly better, with about 60% effectiveness against hospitalization in nine months.
What we observe: The virus has also evolved since the release of the updated boosters, and the threat of new variants that may further evade the protection of the vaccines has not gone away.