AZ's COVID-19 vaccine proves promising in elderly participants, new data shows

Grant Boone
November 23, 2020

"We were pleased to see that our vaccine was not only well tolerated in older adults, but also stimulated similar immune responses to those seen in younger volunteers".

People involved in the Oxford-AstraZeneca vaccine have said they expect their efficacy data, from ongoing late-stage trials, in the coming weeks.

Both low and standard doses of the vaccine triggered responses in both parts of the immune system. Reporting on data from a Phase II trial of the ChAdOx1 nCov-2019 vaccine, the authors write that volunteers in the trial demonstrate similar neutralising antibody titres and T-cell responses across all three age groups (18-55, 56-79 and 70+).

In the peer-reviewed study of the vaccine, healthy adults aged 56 and older showed similar positive immune responses to younger trial participants. "As a result, it is crucial that COVID-19 vaccines are tested in this group who are also a priority group for immunisation". "Further assessment of the efficacy of this vaccine is warranted in all age groups and individuals with co-morbidities", noted the study. The early-stage study involved 560 healthy adults, including 240 people older than 70 years.

AZ is now investigating whether the vaccine candidate can prevent COVID-19 in a global phase 3 clinical trial programme, with studies now ongoing in the United Kingdom, the USA and Brazil.

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The U.K. company is now preparing to submit data to global authorities in order to get a conditional or early approval for its vaccine, the company said.

"Older people's weaker immune systems mean vaccines do not tend to function as well as they do in younger people..."

The study found that adverse reactions to the vaccine were mild, with the most common effects being injection-site pain and tenderness, fatigue, headache, feverishness and muscle pain - however, these reactions were more common than seen with the control vaccine.

Thirteen serious adverse events occurred during the study period as of October 26; however, none were linked to the study's vaccine.

"They must also be safe, effective in preventing disease and/or transmission, and provide at least six months of protection for people frequently exposed to the virus - such as healthcare workers".

Older adults have an increased risk of COVID-19, so it's crucial that vaccines against the disease are effective in this age group.

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