By Jenny Strasburg 

LONDON -- A Covid-19 vaccine being developed by the University of Oxford and AstraZeneca PLC showed a promising immune response and low levels of adverse reactions in the elderly and older adults, according to an interim analysis that the drugmaker said were encouraging.

The vaccine, now in late-stage human trials aimed at showing its efficacy and safety, is a front-runner in the global sprint for a shot to protect lives and jump-start economies hobbled by the pandemic. Trials in the U.K. could produce results before year-end, fueling hopes among scientists and government leaders that a vaccine might be available for high-risk groups here by early 2021.

The results showed positive outcomes for adults over 56, including the especially higher-risk age group of those 70 and older, and were based on analysis of previously conducted interim safety and immune-response data, AstraZeneca and Oxford said Monday.

The elderly generally have been prone to more-severe Covid-19 symptoms than younger people. Thus, researchers have been looking for evidence that a vaccine will be able to specifically help protect them.

"It is encouraging to see immunogenicity responses were similar between older and younger adults," an AstraZeneca spokeswoman said.

"This marks a key milestone and reassures us that the vaccine is safe for use and induces strong immune responses in both parts of the immune system in all adult groups," an Oxford spokesman said Monday.

The data showed a lower "reactogenecity" to the vaccine among older adults. That refers to the level of expected side effects, including potential fever, swelling at the site of the injection and body aches. Such reactions were lower in adults 56 and older than in younger adults, according to the interim analysis. The reactions also lessened after the second of a two-dose application, AstraZeneca said.

Details of the interim analysis have been submitted to a peer-reviewed journal, Oxford and AstraZeneca said. The timing of an expected report isn't clear, but Oxford said it hopes the publication will be in the coming weeks.

Oxford is the sponsor of the vaccine trials in the U.K., while AstraZeneca is overseeing U.S. late-stage trials that were on pause for most of September and October. The company said Friday that the U.S. trials could resume after the Food and Drug Administration wrapped up an examination of a possible neurological side effect that emerged in two people in studies testing the vaccine.

Write to Jenny Strasburg at jenny.strasburg@wsj.com

(END) Dow Jones Newswires

October 26, 2020 08:17 ET (12:17 GMT)

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