'Past COVID infection does not fully protect young people against reinfection'

A past COVID19 infection does not completely protect young people from reinfection and vaccination is still necessary to boost immune response and reduce disease transmission according to an observational study published in The Lancet Respiratory Medicine journalThe research was conducted on more than 3000 healthy members of the US Marines Corps most of whom were aged 1820 years The researchers from the Icahn School of Medicine at Mount Sinai in the US emphasised that young people should take up the vaccine wherever possibleThey noted that despite previous infection and the presence of antibodies vaccination is still necessary to boost immune responses prevent reinfection reduce transmissionAs vaccine roll outs continue to gain momentum it is important to remember that despite a prior COVID19 infection young people can catch the virus again and may still transmit it to others said Professor Stuart Sealfon of Icahn School of Medicine at Mount Sinai a senior author of the studyImmunity is not guaranteed by past infection and vaccinations that provide additional protection are still needed for those who have had COVID19 Sealfon saidIn the study conducted between May and November 2020 around 10 per cent or 19 out of 189 participants who were previously infected with SARSCoV2 seropositive became reinfectedThis was compared to new infections in 50 per cent 1079 out of 2247 of participants who had not previously been infected seronegativeAlthough the study was in young fit mostly male Marine recruits the researchers believe that the risk of reinfection found in their study will apply to many young peopleIn the study US Marine Corps recruits completed an unsupervised quarantine at home for two weeks before entering a Marinesupervised quarantine facility for another two weeksThey received antibody tests to establish whether any of the recruits were seropositive or had previously been infected with SARSCoV2 and had antibodiesThey were also tested for new SARSCoV2 infection at baseline then weeks one and two of the quarantine and completed a questionnaire including demographic information risk factors medical history and COVID19 symptomsOf the 2346 Marines followed long enough for this analysis of reinfection rate 189 were seropositive and 2247 were seronegative at the start of the study Across both groups of recruits there were 1098 45 per cent new infections during the studyAmong the seropositive participants 19 10 per cent tested positive for a second infection during the study Of the recruits who were seronegative 1079 48 per cent became infected during the studyIn the study most new COVID19 cases were asymptomatic 84 per cent 16 out of 19 participants in the seropositive group vs 68 per cent 732 out of 1079 participants in the seronegative group or had mild symptoms and none were hospitalisedOur study shows that some individuals with lower levels of neutralising antibodies were reinfected indicating that it is possible that previously infected and recovered people are susceptible to new SARSCoV2 infection at a later time said Dawn Weir of the Navy Medical Research Centre USThese reinfections may be asymptomatic as observed in the majority of our participants Weir saidThe researchers note some limitations to their study including that it likely underestimates the risk of reinfection in previously infected individuals because it does not account for people with very low antibody levels following their past infectionThis story has been sourced from a third party syndicated feed agencies Midday accepts no responsibility or liability for its dependability trustworthiness reliability and data of the text Midday managementmiddaycom reserves the sole right to alter delete or remove without notice the content in its absolute discretion for any reason whatsoever