May 23, 2020 | 11:21am

Immunity to the coronavirus could only last up to six months, scientists say.

A study at the University of Amsterdam found that those who survived the coronavirus could become reinfected within six months, casting doubt on the concept of “immunity passports” to allow survivors of the virus to return to normal life, according to a report in The Science Times.

For 35 years, University of Amsterdam scientists, led by Lia van der Hoek regularly tested 10 men for four coronaviruses that cause the common cold. While most were reinfected within three years, there were “significant” drops in antibody levels after six months, the study found.

“Coronavirus protective immunity is short-lasting,” van der Hoek said. “We saw frequent reinfections at 12 months post-infection and substantial reduction in antibody levels as soon as six months post-infection. Achieving herd immunity may be challenging due to rapid loss of protective immunity.”