unexampled research has suggested that antibodies to Covid-19 may fade away within two to three calendar month among multitude who were infect but did n’t see any symptom , point that any substantial long - term immunity is unlikely for those mass . However , this does not necessarily signify that these people can be taint a second time , at least in the short term .
While very little is still sleep together about Covid-19 immunity , the study could have some significance for how the world near the ongoing pandemic in the futurity , such as the controversial plans to roll out “ immunity pass ” .
Reporting in the journalNature Medicine , scientist from Chongqing Medical University in China compared the resistant response to SARS - CoV-2 , the computer virus that causes Covid-19 , between symptomless multitude and diagnostic people in the city of Chongqing between January and February of this class .
During the malady , levels of computer virus - specific antibodies were detect to be significantly small in the asymptomatic grouping than in the diagnostic mathematical group , suggesting people without symptom plunge less of an resistant response . They also see that viral shedding — when the body releases the virus , ready to potentially taint others — occurred for 19 days in symptomless people , equate with 14 days in the symptomatic patient role . This suggests some symptomless people could be potentially infective for slightly longer than others .
Eight weeks after the illness had resolved , level of neutralizing antibody decreased by 81 percent in asymptomatic patients , compared to 62 per centum in symptomatic patients . symptomless patients also had lower levels of 18 pro- and anti - inflammatory cytokines , cell - signaling proteins , which further signal a watery immune reaction .
Experts who were not straight regard in the studyhave saidthese findings are “ not surprising ” and are for the most part in line with what ’s already known about soft infections of any cause , although the research has raised concern among some scientist .
" This powerfully suggests that granting immunity may well decrease within months of infection for a substantive proportionality of people,“commentedProfessor Liam Smeeth , Professor of Clinical Epidemiology at the London School of Hygiene and Tropical Medicine .
" We need larger field of study with longer espouse - up in more population , but these findings do suggest that we can not bank on people having had proven infections nor on antibody testing as strong evidence of long term immunity , ” he added .
Some governments have toy with the idea of using“immunity passports”that would allow hoi polloi who can establish they ’ve already been infected with Covid-19 to locomote more freely and get at more public areas . This research , however , propose the architectural plan is not unfailing as it ’s wrong to assume everyone who ’s had Covid-19 has pick up solid long - full term immunity to the disease .
That said , there is some hope that even symptomless patients might be protected from a 2nd infection , at least in the brusk term . Another study write inNaturelast week found that some neutralizing antibodies come up among asymptomatic people in lower layer are actually some of the most hefty . This hints that the lower grade of antibody will still protect you from begin ill again in the short term , although the bountiful question of long - term granting immunity stay unanswered just yet .
