Humans may never develop immunity against Covid-19, according to new research on antibodies by Chinese and American scientists.
Their conclusion was based on a study looking at whether hospital workers in Wuhan who were directly exposed to infected patients at the early stage of the outbreak had developed antibodies. The deadly new disease was first detected in the Chinese city late last year.
At least a quarter of the more than 23,000 samples tested could have been infected with the virus at some stage, according to the scientists. But only 4 per cent had developed antibodies as of April.
“People are unlikely to produce long-lasting protective antibodies against this virus,” the researchers concluded in a non-peer-reviewed paper posted on preprint website medRxiv.org on Tuesday.
Many efforts to fight the pandemic are being done on the assumption that people who have had Covid-19 will produce antibodies that will protect them from reinfection. Those efforts include countries considering issuing “immune certificates”, the over 100 potential vaccines in development, and recovered patients being encouraged to give blood for experimental drugs and therapies.