As we are approaching the probable one-year anniversary of the coronavirus SARS-CoV-2 infecting the first human, experts are faced with yet another critical question: can a person catch the disease more than once? The answer to this question influences, among other things, the prospects of the vaccine and its ability to protect us from the disease.<\/p>\n\n\n\n
To date, there have been around 25 verified cases of COVID-19 reinfection, with various other unverified accounts from around the world. Although this is a comparably small fraction of the millions of people known to have been infected, should we be concerned? To unpick this puzzle, let’s look into it in detail.<\/p>\n\n\n\n
The first confirmed case of Covid-19 reinfection was reported by researchers at the University of Hong Kong in the last week of August. A few other anecdotal cases of reinfection have since emerged, including a few in India.\u00a0In late August, BNO News, an international news agency headquartered in the Netherlands, established the COVID 19 Reinfection Tracker<\/a> which currently lists 24 confirmed cases.\u00a0<\/p>\n\n\n\n According to the tracker, the US state of Washington is presently investigating about 120 suspected cases of reinfection. In Brazil, health officials are reportedly investigating 247 possible cases and a retrospective study in Mexico found 258 suspected cases of reinfection, which included 11 deaths. As none of the Mexican cases were confirmed with genomic sequencing, the tracker has not listed them.<\/p>\n\n\n\n Other countries with cases listed on the tracker include India, Belgium, Qatar, Ecuador, Spain, and Sweden. These confirmed cases highlight the fact that natural infection with COVID-19 does not confer solid immunity as would occur after an infection with measles.<\/p>\n\n\n\n Infection with SARS-CoV-2 leads to a detectable immune response, but the susceptibility of previously infected individuals to reinfection with SARS-CoV-2 is not well understood. SARS-CoV-2 infection results in the generation of neutralising antibodies in patients. However, the degree to which this immune response indicates a protective immunity to subsequent infection with SARS-CoV-2 has not yet been elucidated.<\/p>\n\n\n\n In studies of immunity to other coronaviruses, loss of immunity can occur within 1\u20133 years. Cases of primary illness due to infection followed by a discrete secondary infection or illness with the same biological agent can best be ascertained as distinct infection events by genetic analysis of the agents associated with each illness event.<\/p>\n\n\n\n