ALABAMA – The Centers for Disease Control and Prevention released data from a study showing the efficacy rate of mRNA COVID-19 vaccines waned over the course of several months.

The study focused on adults who were tested for COVID-19 that were either hospitalized or visited emergency rooms and urgent cares. It reviewed data from 10 hospitals from August 2021 to January 2022.

The vaccine efficacy rates were higher during the delta wave than the omicron surge. During both periods, vaccine effectiveness was higher for people who had received a booster dose.

Overall, at emergency rooms and urgent cares, mRNA vaccine effectiveness was 92 percent for those who received two doses of an mRNA vaccine and their booster less than 2 months prior. It decreased to 75 percent after 4 months.

When it came to hospitalizations, vaccine effectiveness for patients receiving a booster within two months of their admission was 95 percent. It decreased to 81 percent after 4 months.

Dr. Wes Stubblefield with the Alabama Department of Public Health says the CDC recommended booster shots to combat a decline in COVID antibody levels. He says the findings are not surprising.

In Alabama, where the vaccination rate is not as high as other states, Stubblefield says the vaccine becoming less effective over time does cause some concern.

“When there is waning effectiveness of the vaccine and a substantial part of the population is not vaccinated, then you got more pool of infectivity out there, so that if something did come along, another variant, something more severe, potentially more people could be infected, and potentially with bad outcomes,” Dr. Stubblefield said.

Stubblefield can’t say if there will be a recommendation for more doses in the future, but he had this to say about verbiage surrounding a person’s vaccine status…

“We’re trying to change our strategy in talking about being vaccinated from fully vaccinated to being up to date. And being up to date means that you have gotten everything you could possibly get for your age and situation. And those are different,” Stubblefield explained.

He also stresses the importance of being vaccinated, pointing to data that shows people who are vaccinated tend to suffer a less severe disease.

On February 11, the CDC updated some of its guidance for booster shots for those who are moderately or severely immunocompromised, including shortening the time frame between the completion of the mRNA vaccine series and when to receive the booster shot.