A fully documented case of COVID-19 reinfection has been found in Hong Kong, but it does not diminish current expectations regarding vaccination effectiveness.
Researchers at the University of Hong Kong have identified a 33 year old patient who had been hospitalized for COVID-19 on March 26. With medical attention he was able to recover. On August 15, a test showed that he had been re-infected with the SARS-CoV-2 virus again, although at this point he is showing to be asymptomatic.
There have been reports of potential re-infection before, but because of the nature of the disease which is known to migrate to different parts of the body, the possibility has been that the re-infections were merely the result of live virus shifting away from tested points to other portions of the body, then returning. In this instance, genetic analysis of disease samples showed that he was dealing with a different strain of the virus than he had previously contracted.
This does not affect the current vaccine expectations for a number of reasons. First and foremost is the rarity of this occurrence. Much as transfer from owners to pets has been documented but seems to be an exceedingly unusual event, this detection demonstrates that a second infection is theoretically possible, not that it is likely. Another is the fact that the re-infection was with a second strain; it may mean that vaccines may best work if tailored to individual strains. As yet, there are only six distinct strains which have been positively identified, each varying only slightly from the others. Some researchers suspect more, but there are few indications of rapid mutation. Another positive finding is that the patient is asymptomatic on his second infection after being hospitalized by the first; it indicates that biological defenses may develop after an initial infection, even if those defenses are not enough to prevent the disease from taking root at all.
This is not a devastating blow to research efforts, although it may be interpreted in some locations as such. It is instead a valuable piece of information in the fight against COVID-19’s spread.
