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NIH Record - National Institutes of Health

Investigational Covid-19 vaccine Well-Tolerated and Generates Immune Response in Older Adults

A nurse gives an older adult a vaccine in the arm

A phase 1 trial of a vaccine to prevent SARS-CoV-2 has shown that the vaccine is well-tolerated and generates a strong immune response in older adults.

The experimental vaccine, mRNA-1273, was co-developed by researchers at NIAID and Moderna, Inc. The phase 1 trial began on Mar. 16 and was expanded to enroll older adults about 1 month later. Older adults are more vulnerable to complications of Covid-19 and are an important population for vaccination. Understanding how the vaccine affects older adults is a critical part of measuring its safety and efficacy.A phase 1 trial of an investigational mRNA vaccine to prevent SARS-CoV-2 infection has shown that the vaccine is well-tolerated and generates a strong immune response in older adults. A report published Sept. 29 in the New England Journal of Medicine describes the findings from the study, which was supported by NIAID.

Overall, the researchers found that the investigational vaccine was well-tolerated in the older age group. Although some volunteers experienced some transient adverse effects, including fever and fatigue after vaccination, the researchers found that they also exhibited a good immune response to the vaccine: the blood of vaccinated volunteers contained robust binding and neutralizing antibodies against SARS-CoV-2. Importantly, the immune response to the vaccine seen in older volunteers was comparable to that seen in younger age groups.

The study will continue to follow the older volunteers for about a year after second vaccination to monitor the long-term effects of the vaccine. According to the researchers, these phase 1 trial results further support testing of the investigational vaccine in older adults in an ongoing large phase 3 trial.

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