An experimental vaccine boosts the immune response in older adults to SARS-CoV-2, the virus that causes COVID-19, and reduces the risk of adverse events as well, the drugmaker reports.

The late-stage trial of AZD1222 had been paused in the United States and abroad after serious neurological reactions occurred in two trial participants. Testing resumed in the U.S. on Friday.

“It is encouraging to see immunogenicity responses were similar between older and younger adults and that [the likelihood of adverse events] was lower in older adults, where the COVID-19 disease severity is higher,” AstraZeneca told CNBC.

In an earlier trial, the vaccine produced a T cell (immune) response within 14 days of vaccination and an antibody response within 28 days, according to BioSpace. The vaccine could provide protection against the novel coronavirus for about a year, and may require a booster or additional vaccination, the news outlet reported.

In related vaccine news

FDA expresses uncertainty about emergency authorization for COVID vaccines Food and Drug Administration officials showed “serious signs” that the agency may back off on the idea of authorizing emergency use of COVID-19 vaccines, clinical news outlet STAT reports. “We are concerned about the risk that use of a vaccine under an EUA would interfere with long-term assessment of safety and efficacy in ongoing trials and potentially even jeopardize product approval,” said Marion Gruber, director of the FDA’s office of vaccines research and review, at an advisory committee meeting last week. “And not only the first vaccine, but maybe even follow-on vaccines.”