By Robert Preidt
THURSDAY, Nov. 19, 2020 (HealthDay News) -- A COVID-19 vaccine under development at Oxford University in England appears safe and triggers an immune response in older adults, researchers report.
Older adults have an increased risk of COVID-19, so it's crucial that vaccines against the disease are effective in this age group.
"Immune responses from vaccines are often lessened in older adults because the immune system gradually deteriorates with age, which also leaves older adults more susceptible to infections," said study author and Oxford professor Andrew Pollard.
"As a result, it is crucial that COVID-19 vaccines are tested in this group who are also a priority group for immunization," he said in a news release from the journal The Lancet.
The phase 2 trial of the ChAdOx1 nCoV-19 vaccine included 560 healthy adults, including 240 older than 70.
It found that the vaccine caused few side effects, was better tolerated in older adults than in younger adults, and produced a similar immune response across age groups.
Both low and standard doses of the vaccine triggered responses in both parts of the immune system. T-cell response occurred within 14 days of the first dose of vaccination, and antibody response occurred within 28 days of the booster dose of vaccination.
"The robust antibody and T-cell responses seen in older people in our study are encouraging," said co-author Dr. Maheshi Ramasamy, also from Oxford.
"The populations at greatest risk of serious COVID-19 disease include people with existing health conditions and older adults. We hope that this means our vaccine will help to protect some of the most vulnerable people in society, but further research will be needed before we can be sure," she said in the release.
The study was published Nov. 19 in The Lancet.
The immune responses reported in the study don't prove that the vaccine protects against infection with the coronavirus. Phase 3 trials are now underway to determine the vaccine's effectiveness against the disease.
For more on COVID-19 vaccines, go to the U.S. Centers for Disease Control and Prevention.
SOURCE: The Lancet, news release, Nov. 19, 2020