Tests show that antibody levels remain high nine months after SARS-CoV-2 infection – whether symptomatic or not.
The longer the pandemic continues, the greater the knowledge of medicine about that Sars-CoV-2-Virus. With the development of a Vaccine has taken a major step in the fight against the pandemic. Anyone who is fully immunized escapes the risk of developing severe or fatal disease or of having to be hospitalized. The question of the duration of the Vaccination protection is currently one of the most burning.
An Italian-British research team investigated this question using tests in the northeastern Italian province of Padua, where the pandemic was rampant from early 2020. Those affected were examined in the municipality of Vò in Veneto. The researchers from the University of Padua and the Imperial College in London tested 85 percent of the 3279 residents with the first in February and March 2020 PCR-Proceedings on Sars-CoV-2 and then in May and November 2020 on neutralizing antibodies against the virus. The results of the study can be found in the English-language journal “Nature Communications“Can be read.
Still detectable nine months later
So it turned out that the Antibody levels Even nine months after a SARS-CoV-2 infection, the disease was still high, regardless of whether the disease was symptomatic, symptomatic (asymptomatic), severe or mild. “We have no evidence that antibody concentrations differ significantly between symptomatic and asymptomatic infections, which is why we assume that immunity by surviving infection has nothing to do with the course of the disease “, says first author Ilaria Dorigatti.” But the number of antibody can vary depending on the method we use to find it in the blood. This can result in differences when comparing different results on this from different parts of the world. “
Antibody levels were tracked using three “assays” – tests that detect different types of antibodies that respond to different parts of the virus. The results showed that although all antibody types showed some decrease between May and November, the rate of decay varied depending on the assay.
The team also found cases of increased antibody levels in some people, suggesting possible re-infection with the virus and boosting the immune system.
Risk of contagion in the household
The team also looked at the infection status of other people in the household to assess the likelihood that an infected member would pass the infection on within the household. The research group’s modeling indicated a 26 percent risk that a person infected with SARS-CoV-2 would pass the infection on to another person in the household.
Safety rules also important after vaccination
According to the models, only 20 percent of those infected cause 79 percent of the infections, and the majority of Covid patients do not spread the disease any further. “These huge differences suggest that behavior remains a key to controlling the epidemic. Distance, masks and contact restrictions remain an important factor, even if more and more people are vaccinated,” says co-author Enrico Lavezzo of the University of Padua.
The “study also shows that manual contact tracing – the search for positive individuals on the basis of known and explained contacts – would have had a limited impact on containing the epidemic had it not been accompanied by mass screening,” reports the head of the Research project, Professor Andrea Crisanti from the University of Padua in one Press release.