However, since many cases are asymptomatic and therefore unlikely to have tested positive initially, it may be impossible to know if a given Covid-19 case is the first or second infection.
In a linked comment to The Lancet paper, Akiko Iwasaka, a Professor of Immunobiology and Molecular, Cellular and Developmental Biology at Yale University, said the findings could impact public health measures.
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"As more cases of reinfection surface, the scientific community will have the opportunity to understand better the correlates of protection and how frequently natural infections with SARS-CoV-2 induce that level of immunity," she said.
"This information is key to understanding which vaccines are capable of crossing that threshold to confer individual and herd immunity," added Iwasaka, who was not involved in the study.
(Writer: Patrick Galey)
Source: http://u.afp.com/3KCt
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