New data on COVID-19 vaccines' effectiveness against omicron, among immunocompromised
One English analysis showed how COVID-19 boosters increase protection against symptomatic infection from omicron, while two studies looked at vaccinating the immunocompromised, and ACP videos worked to educate patients and increase vaccine uptake.
The effectiveness of the COVID-19 vaccines against the omicron variant was quantified by a new study.
Researchers in England used data from Nov. 27, 2021, to Jan. 12, 2022, on 886,774 people infected with the omicron variant, 204,154 infected with the delta variant, and 1,572,621 controls who tested negative to estimate the effectiveness of the Pfizer-BioNTech and AstraZeneca primary vaccines and Pfizer-BioNTech and Moderna boosters against symptomatic COVID-19. Results were published by the New England Journal of Medicine on March 2.
The study found that two doses of the Pfizer-BioNTech vaccine was 65.5% (95% CI, 63.9% to 67.0%) effective against omicron at two to four weeks after the second shot, dropping to 8.8% (95% CI, 7.0% to 10.5%) at 25 or more weeks. A booster brought effectiveness up to 67.2% (95% CI, 66.5% to 67.8%) at two to four weeks, dropping 45.7% (95% CI, 44.7% to 46.7%) at 10 or more weeks. A Moderna booster after the Pfizer-BioNTech primary series increased vaccine effectiveness to 73.9% (95% CI, 73.1% to 74.6%) at two to four weeks, falling to 64.4% (95% CI, 62.6% to 66.1%) at five to nine weeks. Two doses of the AstraZeneca vaccine showed no effect against omicron at 20 weeks, but adding a Pfizer-BioNTech or Moderna booster to that vaccine provided similar protection.
The authors noted several study limitations, including that they were unable to determine protection against severe forms of disease owing to the small number of omicron cases resulting in hospitalization in the data set. In addition, differences in the populations receiving the various vaccines may have confounded the results.
In other COVID-19 vaccine research, a systematic review, published by The BMJ on March 2, analyzed the reduced efficacy of two doses of the vaccines in immunocompromised patients. A randomized trial of HIV and solid-organ transplant patients, published by Clinical Infectious Diseases on March 2, compared the Pfizer-BioNTech and Moderna vaccines and found that all HIV patients had antibody responses while only 60% of transplant recipients did, with similar results between the vaccines. A CDC study, published by MMWR on March 4, found that first-dose vaccination coverage is much lower in rural U.S. counties than in urban ones (58.5% vs. 75.4%).
ACP has been working to improve vaccination uptake with the “Ask Your Internist” and “Physician to Physician Conversations” video series. The videos were developed in partnership with YouTube to present practical strategies for physicians and other health care professionals to address COVID-19 misinformation and build vaccine confidence, as well as to provide accurate medical information to patients from trusted physician messengers.
Since the debut of each series in November 2021, the videos have earned more than 400,000 views, produced five of ACP YouTube Channel's 10 most watched videos, and increased subscriptions to the channel by more than 10%. Episodes of “Ask Your Internist” and “Physician to Physician Conversations” are available to watch on ACP's YouTube Channel, along with other ACP video content.