Young people are more likely to report Covid-19 reinfection, according to a study published in the preprint server MedRxiv.
The authors of the study, including those from Mount Sinai, the Naval Research Centre, examined 3,249 young, healthy, mostly male Marine recruits between the ages of 18-20 before they started basic training.
Of the 189 participants that tested positive for antibodies, 19 ended up testing positive for the virus six weeks later, according to the study.
“Our findings indicate that reinfection by SARS-CoV-2 in healthy young adults is common,” said Mount Sinai’s Dr Stuart Sealfon in a release.
The researchers noted that though “antibodies induced by infection to SARS-CoV-2 are largely protective, they do not guarantee effective immunity against subsequent infection.”
The results revealed that of the 19 recruits who were reinjected, 84.2 per cent, or 16 of them, didn’t show any symptoms at all.
Researchers noted that overall, many young people who contract the virus tend to be asymptomatic or have few symptoms. This can lead to a less robust immune memory response.
“This could lead to higher overall rates of re-infection among this population compared to other populations,” researchers wrote.
They added that those who are reinfected could “have a similar capacity” to transmit the infection as those who are infected the first time.
The researchers also pointed out that little is known about vaccine immunity and said it is “possible that both previously infected and vaccinated individuals may later become infected” again.
The researchers concluded that young adults “can be an important source of transmission to more vulnerable populations.”