A small study of older Americans fully vaccinated with Pfizer or Moderna jabs suggested they dropped their risk of COVID-19 hospitalization by 94%, compared to an unvaccinated group of the same age, according to the Centers for Disease Control and Prevention (CDC).
Partially vaccinated patients (two weeks post-first dose) cut their hospitalization risk by 64%, per results said to be the first real-world findings in the U.S. indicating mRNA vaccines protect against severe illness, on par with clinical trials.
“The findings suggest that SARS-CoV-2 vaccines can reduce the risk for COVID-19–associated hospitalization and, as a consequence of preventing severe COVID-19, vaccination might have an impact on post-COVID conditions (e.g., “long COVID”) and deaths,” CDC researchers wrote.
Findings posted Wednesday drew from 417 patients over age 65, including 230 controls who tested negative for the virus and 187 patients who tested positive, spanning 24 hospitals in over a dozen states. More specifically, among the virus-positive patients, 10% were partially vaccinated before symptoms occurred, compared with 27% of control patients who were at least partially vaccinated. The proportion of the vaccines administered, between Pfizer and Moderna, was said to be similar (53% and 47% respectively).
“This highlights the continued risk for severe illness shortly after vaccination, before a protective immune response has been achieved and reinforces the need for vaccinated adults to continue physical distancing and prevention behaviors, such as use of face masks and recommended hand hygiene at least 14 days after the second dose of a 2-dose vaccine,” CDC researchers wrote.
“These findings are encouraging and welcome news for the two-thirds of people aged 65 and up who are already fully vaccinated,” said Dr. Rochelle P. Walensky, CDC director, in a related release. “COVID-19 vaccines are highly effective and these real-world findings confirm the benefits seen in clinical trials, preventing hospitalizations among those most vulnerable. The results are promising for our communities and hospitals. As our vaccination efforts continue to expand, COVID-19 patients will not overwhelm health care systems – leaving hospital staff, beds, and services available for people who need them for other medical conditions.”
Separate early results on the real-world vaccine rollout in Israel indicated the Pfizer vaccine dropped symptomatic COVID-19 by 94%, though the CDC researchers lauded the study at hand because it included both Moderna and Pfizer vaccines, saying both afford high protection. The U.S. study had its limitations, including wide confidence intervals due to the small sample size, potential flaws in self-reported data regarding vaccine status and illness onset and a geographically unrepresentative sample of the country’s population.
President Joe Biden, addressing the CDC’s updated guidance in a White House briefing Tuesday, which eased mask use recommendations for fully vaccinated populations while outdoors, noted over 67% of adults over age 65 are fully vaccinated, and more than 80% have received at least one dose.
“That effort resulted in a drop of 80 percent in deaths among American seniors, a 70 percent drop in hospitalizations,” the president said, adding the proportion of vaccinated older adults is “essentially equal between White and seniors of color.”