Moderna COVID-19 vaccine remains effective for 5.3 months after second dose

From July 27 to October 23, 2020, individuals were randomly given their first dose, with their follow-up 28 days after.

“Overall, we saw lower incidence rates of COVID-19 cases in July and August among participants who were more recently vaccinated, but it’s important to keep in mind that the numbers we’re seeing are far from reduced to the initial risk, “Lindsey Baden, MD, a physician in the Division of Infectious Diseases at Brigham and Women’s Hospital, said in a statement.

After the FDA granted emergency use clearance for Moderna’s vaccine, the COVE trial was amended to include 2 parts that monitored individuals who had previously received the vaccine and administered the vaccine to those who had received. the placebo.

“The rapid overhaul of the COVE study has allowed us to successfully retain study participants and will allow us to investigate longer-term safety and efficacy,” Baden said. “Using established and new study methods, we were able to continue to compare results for those who were vaccinated earlier versus later in the study population.”

After 14 days since the second dose, investigators found that the vaccine was 93.2% effective against COVID-19 compared to the placebo group.

Prevention remained constant throughout follow-up, with greater than 90% effectiveness 4 months or more after the second dose.

“Overall, our results continue to show that vaccines work and work extremely well in preventing COVID-19,” Baden said.

“We continue to explore questions about the duration of immunity after vaccination and the impact of variants. But even if we look at the possibility of decreased immunity, we see evidence that the vaccine is still very protective, ”Baden said.

Safety was also assessed continuously in the group, with adverse events 7 days after vaccination, such as fatigue, headache, joint pain and muscle pain.

The vaccine’s efficacy was also high in individual subgroups such as people 65 years of age or older, people 75 years of age or older, different ethnic and racial groups, people with co-morbidities and those exposed to occupational risks.

“The message here is not that if you were vaccinated early, you are not protected. People vaccinated more recently may see marginal improvement, but both groups enjoy protection compared to people who were not vaccinated, ”Baden said.

The same group of researchers also published results on MedRxiv which explored the analysis of people who received the vaccine between July and December 2020 and those who received the placebo between December 2020 and March 2021.

Reference

Phase 3 trial results: mRNA-1273 vaccine remained safe and effective for more than five months after the second dose. EurekAlert. Press release. September 22, 2021. Accessed September 23, 2021. https://www.eurekalert.org/news-releases/929287