The initial findings have yet to undergo the peer review process.
Rabat – A recent Wuhan-based study suggests there may be no immunity against COVID-19. The theory follows antibody tests on samples from hospital workers who were directly exposed to COVID-19 patients at an early stage of China’s outbreak.
According to the study, only 4% of the studied population of 23,000 had antibodies, although the researchers estimate at least 25% of participants could have contracted COVID-19.
Antibodies are blood proteins the body produces to neutralize pathogens such as bacteria and viruses. They “memorize” previously defeated pathogens for better immunity in the second strike by the same virus or bacteria, and could be a serious boon for the fight against COVID-19.
The study is led by Dr. Wang Xinhuan from University Hospital Zhongnan in Wuhan and scientists from the University of Texas in Galveston.
Chinese and American scientists conducted the study on hospital workers in Wuhan who were directly exposed to infected patients, according to South China Morning Post.
Published on www.medrxiv.org but yet to undergo peer review, researchers said that “people are unlikely to produce long-lasting protective antibodies against this virus.”
Several countries are now providing recovered COVID-19 patients with an “immune certificate.” The researchers worry that such efforts could be based on a false assumption that recovered patients produce long-lasting antibodies.
Dr. Wang said that with the new insight, “the idea of an immune certificate for recovered COVID-19 patients is invalid.”
“Our findings have important implications for herd immunity, antibody-based therapeutics, public health strategies, and vaccine development,” Wang’s team said.
On the other hand, the director of antibody engineering research at the Southern Medical University in Guangzhou, Wu Yingsong, said that the Wuhan study should be treated with caution, indicating that “there are still a lot of fundamental things about the coronavirus we don’t understand.”
In South Korea, on April 10, the World Health Organization (WHO) started examining 91 recovered COVID-19 patients who tested positive for a second infection.
In line with Yingsong’s caution, WHO said during the South Korean operation that “COVID-19 is a new disease, we need more epidemiological data to draw any conclusions of virus shedding profile.”