New research suggests that Moderna’s protection against COVID-19 lasts for at least six months.
The report, published in the New England Journal of Medicine on Tuesday, echoes what Pfizer said last week about his vaccine, which works similarly.
Both reports were based on follow-up tests on dozens of people who received the vaccines during studies that led to the use of the vaccines. These studies were done before the advent of new variants or versions of coronavirus, which began to spread.
A separate report in the medical journal adds concern about the variants. The scientists measured antibodies that can block the virus in 50 people who were given Sinopharm or Sinovac vaccines that were developed in China. Many have experienced a total or partial loss of efficacy against a virus variant first detected in South Africa.
Vaccines still seemed to protect against a variant first found in the United Kingdom, which is now spreading rapidly in the United States and elsewhere.
Pfizer and Moderna said they are working to update their vaccines or possibly design a booster shot, if needed against variants.