A large-scale Icelandic study reveals the presence of antibodies, massive, four months after infection.
How long do you stay immune to Covid-19 after being infected? The question, a major issue in the fight against the coronavirus, has agitated the scientific world since the start of the pandemic. An Icelandic study provides some answers.
“The New England Journal Of Medecine”, measured the presence of antibodies in patients who tested positive for coronavirus over time. The study concludes that antibodies against Covid-19 did not decrease within 4 months of diagnosis. “Data-reactid =” 25 “> The study, published in “The New England Journal Of Medecine”, measured the presence of antibodies in patients who tested positive for coronavirus over time. The study concludes that antibodies to Covid-19 did not decrease within 4 months of diagnosis.
Antibodies increasing for two months
To reach these conclusions, the researchers conducted tests on more than 30,000 people in Iceland. Scientists used two different types of coronavirus tests: nasal swabs, which detect virus fragments indicating infection, and tests that measure antibodies in the blood, which can determine whether a person is currently infected. or if it has already been.
Among the group of people who tested positive, further testing found that antibodies rose for two months after their infection was diagnosed, and then remained stable for the next two months. Or a proven presence of antibodies four months after infection.
Immunity “may not be ephemeral”
To explain the result of previous studies, which suggested a rapid disappearance of antibodies after infection, the researchers hypothesize: these studies may have looked at the first wave of antibodies that the immune system produces in response to an infection. But a second wave of antibodies forms after a month or two of infection, and these seem more stable and long-lasting. Hence the stable presence of antibodies four months after infection.
case of reinfection observed in some countries, several months after the first infection, nor to establish whether patients with a severe form of Covid-19 produce more antibodies than the milder forms. “data-reactid =” 31 “> This study does not, however, explain the rare case of reinfection observed in some countries, several months after the first infection, nor to establish whether patients with a severe form of Covid-19 produce more antibodies than the milder forms.
More antibodies in severely ill patients
Nevertheless, scientists have noted differences in the presence of antibodies between patients. Thus, antibody levels were higher in older people and those who were more severely affected by the virus, while in women, who tend not to get as sick as men from the virus, the rate antibody count was lower. Finally, smokers had lower antibody levels than the average patient.
If the study does not advance the quantity of antibodies necessary to be immunized against an infection, this new data is important in the fight against Covid-19, in particular with a view to a potential vaccine. As scientists at Harvard University write in a commentary accompanying the study, if a vaccine can stimulate long-lasting antibody production as a natural infection appears to do, it gives hope that “immunity to this unpredictable and highly contagious virus may not be ephemeral ”.
