LONDON — Developers of the Oxford-AstraZeneca vaccine expect to have a modified jab to cope with the South Africa coronavirus variant by autumn, the vaccine's lead researcher said Sunday.

Health officials in Britain are trying to contain the spread of the variant first identified in South Africa amid concerns that it is more contagious or resistant to existing vaccines. More than 100 cases of the South African variant have been found in the U.K.

Sarah Gilbert, lead researcher for the Oxford team, told the BBC on Sunday that "we have a version with the South African spike sequence in the works." 

"It looks very likely that we can have a new version ready to use in the autumn," she added.

Her comments came as Oxford University said that early data from a small study suggested that the AstraZeneca vaccine offers only "minimal protection" against mild disease caused by the South Africa variant.

The study, which has not yet been peer reviewed, involved 2,000 people, most of whom were young and healthy. The volunteers' average age was 31. 

"Protection against moderate-severe disease, hospitalization or death could not be assessed in this study as the target population were at such low risk," Oxford University said.

Robin Shattock, a scientist who is leading the coronavirus vaccine research at Imperial College London, urged caution about the study's early findings. But he said it was "concerning to some extent that we're seeing that it's not effective against mild or moderate disease." 

Authorities in England last week went house-to-house to administer COVID-19 testing in eight areas where the South Africa variant is believed to be spreading, after a handful of cases were found in people who had no contact with the country or anyone who travelled there.

The testing blitz is a bid to snuff out the variant before it spreads widely and undermines the U.K.'s vaccination rollout. Public health officials are concerned about the South Africa variant because it contains a mutation of the virus' characteristic spike protein, which is targeted by existing vaccines.

Britain has seen Europe's deadliest coronavirus outbreak, with over 112,000 confirmed deaths, but it has embarked on a speedier vaccination plan than the neighboring European Union. So far the U.K. has given a first coronavirus vaccine jab to about 11.5 million people.