The reporting of multiple cases of re-infection in the United States, Europe and Asia shows that there is still much to learn about the immune response and also raises questions about vaccination.
“It is becoming more and more obvious that re-infections are possible”
As part of the work presented in the journal Lancet Infectious Diseases, various cases of reinfection have been reported, including that of a 25-year-old American from Reno, in the Nevada. Now recovered, the man had tested positive last April after showing mild symptoms, then contracted the disease a second time in May, in a more severe form. Although this type of case seems rare, its occurrence in different parts of the globe, especially theSouth East Asia, worries researchers.
To the Netherlands, the National Institute of Public Health confirmed earlier this week that an 89-year-old Dutch woman, also suffering from a rare form of bone marrow cancer, recently died after contracting the Covid-19. According to local media, this would be the first known case of death following reinfection with SARS-CoV-2.
“ It is becoming more and more evident that re-infections are possible, but we are not yet able to determine how often they appear. “, said Simon clarke, expert in microbiology atBritish University of Reading. ” If people can be re-infected easily, this could also have implications for immunization programs as well as for our understanding of when and how the pandemic will end.. “
The possibility of collective immunity again called into question
The patient’s doctors Nevada, who first reported the case in August in an unpaired paper, said sophisticated testing had shown that the virus strains associated with each episode of infection were genetically different. According to the study authors, “ these results highlight the fact that we do not yet know enough about the immune response to this infection “.
” The fact that it is possible to be re-infected with SARS-CoV-2 suggests that a vaccine against Covid-19 may not offer full protection », Estimated Brendan Wren, professor of vaccinology at the London School of Hygiene & Tropical Medicine, specifying that the case of Nevada was the fifth confirmed example of reinfection in the world.
” However, given the (over) 40 million cases reported worldwide, this tiny number of re-infections should not disrupt efforts to develop vaccines. “, he added.
TheWorld Health Organization, through its spokesperson Tarik Jasarevic, also agreed that the US case highlighted a lack of knowledge about the immune response, once again questioning the possibility of herd immunity.