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.
Led by Wang Xinhuan from Wuhan University's Zhongnan Hospital and scientists from the University of Texas in Galveston, the study looked at samples from health care workers and general hospital staff in the city.
Wang's team also suggested that more than 10 per cent of the people in their study may have lost antibody protection within a month or so.
"Our findings have important implications for herd immunity, antibody-based therapeutics, public health strategies, and vaccine development," they said.
Based on their research, they said antibody tests may not be enough to tell whether someone had been infected, and the presence of antibodies like IgG may not necessarily provide immunity later.
"The idea of an immune certificate for recovered Covid-19 patients is invalid," Wang wrote.
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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.
Led by Wang Xinhuan from Wuhan University's Zhongnan Hospital and scientists from the University of Texas in Galveston, the study looked at samples from health care workers and general hospital staff in the city.
Wang's team also suggested that more than 10 per cent of the people in their study may have lost antibody protection within a month or so.
"Our findings have important implications for herd immunity, antibody-based therapeutics, public health strategies, and vaccine development," they said.
Based on their research, they said antibody tests may not be enough to tell whether someone had been infected, and the presence of antibodies like IgG may not necessarily provide immunity later.
"The idea of an immune certificate for recovered Covid-19 patients is invalid," Wang wrote.
There may be no immunity against Covid-19, new Wuhan study suggests
Researchers behind the non-peer-reviewed paper ran antibody tests on samples from hospital workers who were exposed to patients at early stage of outbreak – only 4 per cent had them, but at least 25 per cent could have been infected.
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