People receiving a COVID-19 booster that is a different brand from their primary vaccine line may be better protected against COVID-19, according to a examination from Singapore published 11 February in Journal of the American Medical Association.
Using national data from the Singapore Ministry of Health, researchers analyzed the incidence and severity of COVID-19 cases between September 15 and October 31, 2021 among people 60 years and older who were eligible to receive booster shots. Out of more than 703,000 eligible individuals, 576,132 received Pfizer or Moderna boosters.
Individuals who received the Pfizer vaccine for their primary series and booster had a COVID-19 incidence rate of 227.9 per day. million person days compared to 147.9 for people who received Pfizer for the primary series and Moderna for the booster. Among those who received Moderna shots for their primary series, the infection rate was 133.9 cases per day. million people with a Moderna booster and 100.6 per. million person days with a Pfizer booster.
Overall, people who received a booster had a lower incidence of severe COVID-19 than people who did not.
“The study results support recommendations for vaccine boosters and suggest that heterologous boosting may provide greater protection against COVID-19,” the researchers concluded.
See the full survey here.