A study has revealed that patients who recovered from COVID-19 risk contracting the virus again after six months.
The research findings, the researchers said, has cast further doubt over the prospect of long-lasting immunity from COVID-19.
The team of researchers from the University of Amsterdam had engaged 10 volunteers for 35 years and tested them every month for four seasonal and weaker coronaviruses, which usually cause mild illnesses similar to the common cold.
According to Daily Mail, the researchers discovered that those who had been infected with the strains — from the same family as SARS-CoV-2, the type that causes COVID-19 — had ‘an alarmingly short duration of protective immunity’.
“Levels of antibodies, substances stored by the immune system to allow the body to fight off invaders in the future, dropped by 50 per cent after half a year and vanished completely after four years.
By studying how people recover from viruses from the same family as the one that causes COVID-19, the scientists say their research is the most comprehensive look at how immunity might work for the disease that emerged in China last year,” the report said.
The latest study, which suggests that immunity to the virus would last for a similar time as the protection given from a flu jab against seasonal influenza, did not reveal if the patients suffered less severe bouts of illness after being reinfected.
The development is coming against the backdrop of claims by British pharma giant, AstraZeneca, that the experimental Oxford University COVID-19 vaccine it is manufacturing would be able to protect people from getting infected with the disease for a year.