Newly published research from Hong Kong University reveals the first confirmed case of SARS-CoV-2 reinfection, raising new questions while offering a small sliver of hope. The confirmation of the reinfection was made possible by testing the viral genomes from the infected person and comparing the differences between the viruses acquired during the first and second infections.
The reinfection case involved a 33-year-old man who lived in Hong Kong and was first infected with the virus behind COVID-19 in March 2020. The infection was confirmed with testing. This individual eventually recovered from the infection and, months later, traveled to Spain.
The former patient returned to Hong Kong this month, according to researchers, and was screened at the Hong Kong airport as part of measures to curb the spread of the virus. The man’s test came back positive for the virus…but this time around, he didn’t have any COVID-19 symptoms. How do the researchers know this is a case of reinfection, not simply detecting the original virus still in his body?
A new study on the case reveals that viral genomes were extracted from the virus retrieved from the patient using swabs. These two sample genomes were contrasted with each other, revealing that the first one from March was linked to strains passing around in the US and England during that time. The second strain identified in August, meanwhile, was closer to strains found in Europe later this summer.
Experts say the lack of symptoms in the second case is a positive sign, one indicating that after initial infection, the body may be able to properly fight off the virus, depriving it of the chance to cause illness. This is bittersweet news — it seems that SARS-CoV-2 reinfection is possible within months of the initial illness, but it also indicates that subsequent illnesses may be mild or asymptomatic.
Of course, there is one big ‘catch’ in all of this, and it’s that — at this point in time — the data comes from a single case. It will take time for additional reinfection cases to surface, giving experts additional opportunities to study the virus and how the body handles it the second time around.