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Caution is warranted about how population level serology studies and individual tests are used. It is not yet established whether the presence of detectable antibodies to SARS-CoV-2 confers immunity to further infection in humans and, if so, what amount of antibody is needed for protection or how long any such immunity lasts.3 Data from sufficiently representative serological studies will be important for understanding the proportion of a population that has been infected with SARS-CoV-2. These data might inform decisions to ease physical distancing restrictions at the community level, provided that they are used in combination with other public health approaches.5 The use of seroprevalence data to inform policy making will depend on the accuracy and reliability of tests, particularly the number of false-positive and false-negative results, and requires further validation.6 At the individual level, this reliability could have public health ramifications: a false-positive result might lead to an individual changing their behaviour despite still being susceptible to infection, potentially becoming infected, and unknowingly transmitting the virus to others. Individual-targeted policies predicated on antibody testing, such as immunity passports, are not only impractical given these current gaps in knowledge and technical limitations, but also pose considerable equitable and legal concerns, even if such limitations are rectified.
(tags: immunity covid-19 future society vaccination)