Italian scientists reported that they found antibodies to the SARS-CoV-2 coronavirus in blood samples isolated from asymptomatic patients back in September 2019, six months before the large-scale spread of the pathogen. According to the researchers, the unexpected results indicate that the pandemic could have started much earlier than experts believe WHO . Scientific work published in SAGE journals.
Scientists have identified antibodies to pandemic coronavirus in 111 people among 959 people who underwent lung cancer screening between September 2019 and March 2020. 14 percent of cases were detected in September 2019 and over 30 percent in the second week of February 2020. Moreover, more than 50 percent of patients with antibodies to the receptor-binding domain (RBD) of the S-protein of coronavirus were found in Lombardy, a region in northern Italy.
According to experts, the results show an odd circulation of the virus among asymptomatic individuals in Italy several months before the first patient was identified in the country.
At the same time, the detection of antibodies to coronavirus in people who have not had COVID-19 is not an exceptional case. For example, it is known that antibodies to SARS-CoV-2 may appear in those who has been infected with a related virus that causes the common cold. There is also evidence that antibodies that neutralize SARS-CoV-2 are also present in the body of people who recovered from SARS in 2003. However, specific antibodies that target RBD in patients not exposed to pandemic coronavirus are still not detected .
To confirm the conclusions of the Italian scientists, it is necessary to conduct additional studies and prove that antibodies to RBD S-protein cannot arise as a result of the development of cross-immunity under the influence of related viruses, and also to exclude the possibility of contamination of samples.