LONDON (Reuters) – Britain’s approval of a COVID-19 antibody test is an “important breakthrough” and might lead to Britons being able to use health certificates if antibodies are present, a spokesman for Prime Minister Boris Johnson said on Thursday.

The antibody tests – also known as serology tests – show who has been infected, although it is not yet clear whether the presence of antibodies to the new coronavirus confers permanent immunity.

“We’ve talked about in the future the potential for some kind of health certificate related to whether or not you have antibodies but we need a better understanding of the immune system response to the virus and the length and level of immunity following infection to better understand the potential of the test,” the spokesman told reporters.

“It’s clearly an important breakthrough that we have a test which has been found to be highly specific, but work will continue to better understand the full potential of the tests … “It does continue to have the potential to be a game changer.”

(Reporting by Elizabeth Piper; editing by Stephen Addison)