Vaccine effectiveness against hospitalization drops slightly, CDC says
The COVID-19 vaccines' ability to keep people out of the hospital appears to be dropping slightly, particularly for those 75 and older, although the vaccines still remain highly effective at preventing serious illness, according to an analysis by the Centers for Disease Control and Prevention presented Monday during an advisory panel.
![PHOTO: A syringe is filled with a dose of the Pfizer Covid-19 vaccine at a mobile vaccination clinic during a back to school event at the Weingart East Los Angeles YMCA in Los Angeles, Aug. 7, 2021.](https://s.abcnews.com/images/Health/vaccine-california-gty-jt-210817_1629229868768_hpMain_2.jpg)
The CDC has previously estimated that 97% of people in the hospital being treated for COVID-19 are unvaccinated, but that data was collected before the spread of delta, a hyper-transmissible variant that many doctors have warned appears to be making people sicker.
Health experts are also concerned that a person’s immunity could be waning over time, particularly among older people whose bodies are less likely than young people to develop a strong immune response to the vaccines.
The latest CDC analysis estimates that the ability of the COVID vaccines to keep a person out of the hospital is now between 75% to 95%.
For people older than 75 in particular, vaccine effectiveness against hospitalization experienced the steepest decline, from more than 90% to 80% between June and July.
However, the vaccines still remain highly effective at preventing serious illness, according to the briefing. "COVID-19 vaccines continue to maintain high protection against severe disease, hospitalization, and death," the CDC notes.
-ABC News’ Anne Flaherty