In news that may discourage millions of coronavirus survivors, a new study has shown that antibodies "evaporate" in the airways rapidly after infection with the virus! However, vaccination has a positive effect later on and significantly increases antibody levels after two doses, according to a new study from the Karolinska Institute in Sweden.
The study's results indicated that receiving a second vaccine dose after recovering from COVID-19 may be important for protection against reinfection and preventing its transmission. In this context, Anna Sørensen, who led the research, explained, according to the journal "GCL Insight," that what makes the study unique is that we looked at samples from both blood and airways; this provided us with new insights into immune responses in areas affected by the virus, which is rare in studies due to the difficulty of sampling the airways. Hence, we knew little about antibody levels in that area compared to blood.
The Good News!
While the article deemed the quick return of antibodies after vaccination in those previously infected with the virus as good news, it noted this was the case not only in the blood but also in the airways. Scientists found that antibody levels in the airways after two vaccine doses were often higher than during the course of the disease. In contrast, individuals who had not been infected before vaccination showed much lower or even undetectable levels.
Moreover, Karen Lurie, a co-author of the study, pointed out that "the results of this research showed that studying blood alone does not reflect antibody levels in the respiratory system, which likely play a key role in neutralizing the virus where it exists. Therefore, completing vaccination with a second dose may be important for achieving optimal immune responses and reducing the spread of infection among individuals."
It is worth noting that the required antibody level for protection against infection remains unknown, despite all the studies conducted on this topic.
