A COVID-19 vaccine from Oxford University and AstraZeneca in late-stage trials is found to be well tolerated, and produced a strong immune response in people over age 70, according to findings published in the Lancet.

A key researcher at the university says this is important because vaccines often don’t work as well in older people.

Dr. Andrew Pollard says scientists expect to report results from the late-stage trials of their COVID-19 vaccine by Christmas.

Dr. Pollard, an expert in pediatric infection and immunity at Oxford, said Thursday that research was slowed by low infection rates over the summer, but the Phase III trials are now accumulating the data needed to report results.

He told the BBC, “I think we’re getting close, and it’s definitely going to be before Christmas based on the progress.”

Unlike the vaccines from Pfizer and Moderna, which use new technology known as messenger RNA, the AstraZeneca experimental shot is a viral vaccine made from a weakened version of the common cold virus found in chimpanzees.