Background
Residents of nursing homes (NH) are at high risk of COVID-19 related morbidity and death and may respond poorly to vaccination because of old age and frequent comorbidities.
Methods
Seventy-eight residents and 106 staff members, naïve or previously infected with SARS-CoV-2, were recruited in NH in Belgium before immunization with two doses of 30µg BNT162b2 mRNA vaccine at day 0 and day 21. Binding antibodies (Ab) to SARS-CoV-2 receptor binding domain (RBD), spike domains S1 and S2, RBD Ab avidity, and neutralizing Ab against SARS-CoV-2 wild type and B.1.351 were assessed at days 0, 21, 28, and 49.
Results
SARS-CoV-2 naïve residents had lower Ab responses to BNT162b2 mRNA vaccination than naïve staff. These poor responses involved lower levels of IgG to all spike domains, lower avidity of RBD IgG, and lower levels of Ab neutralizing the vaccine strain. No naïve resident had detectable neutralizing Ab to the B.1.351 variant. In contrast, SARS-CoV-2 infected residents had high responses to mRNA vaccination, with Ab levels comparable to infected staff. Cluster analysis revealed that poor vaccine responders not only included naïve residents but also naïve staff, emphasizing the heterogeneity of responses to mRNA vaccination in the general population.
Conclusions
The poor Ab responses to mRNA vaccination observed in infection naïve residents and in some naïve staff members of NH suggest suboptimal protection against breakthrough infection, especially with variants of concern. These data support the administration of a third dose of mRNA vaccine to further improve protection of NH residents against COVID-19.
Background
Residents of nursing homes (NH) are at high risk of COVID-19 related morbidity and death and may respond poorly to vaccination because of old age and frequent comorbidities.
Methods
Forty residents and forty staff members either naïve or previously infected with SARS-CoV-2 were recruited in two NH in Belgium before immunization with two doses of 30μg BNT162b2 mRNA vaccine at day 0 and day 21. Binding antibodies (Ab) to SARS-CoV-2 receptor binding domain (RBD), spike domains S1 and S2, RBD Ab avidity, and neutralizing Ab against SARS-CoV-2 wild type and B.1.351 variant were assessed at days 0, 21, 28, and 49.
Results
SARS-CoV-2 naïve residents had lower Ab responses to BNT162b2 mRNA vaccination than naïve staff. These poor responses involved lower levels of IgG to all domains of the vaccine antigen, lower avidity of RBD IgG, and lower levels of Ab neutralizing the vaccine strain. No naïve resident had detectable neutralizing Ab to the B.1.351 variant. High and comparable Ab responses were observed in residents and staff previously infected with SARS-CoV-2. Clustering analysis revealed that poor vaccine responders not only included naïve residents but also naïve staff, emphasizing the heterogeneity of responses to mRNA vaccination in the general population.
Conclusions
The poor Ab responses to mRNA vaccination observed in infection naïve residents and in some naïve staff members of NH suggest suboptimal protection against breakthrough infection, especially with variants of concern. Adapted vaccination regimens may be needed to provide optimal protection against COVID-19 to vulnerable populations.
At the end of 2017 and 2018 two different unknown suspicious preparations were encountered and were subjected to a plethora of different analyses in order to identify, if present, any bioactive compound. It turned out that these samples contained the assumedly cognitive enhancing research peptides Selank and Semax, which, to our knowledge, have not completed any clinical trials. Moreover, an online search, excluding the dark web, demonstrated that these kinds of nootropic research peptides are freely available either as lyophilized powder for injection purposes or are present in nasal sprays. It stands to reason that controlling laboratories need to anticipate the uprising of these types of potentially dangerous molecules and must therefore be able to correctly identify these compounds. Therefore, these findings served as an incentive to develop a novel combined liquid chromatography tandem mass spectroscopy (LC–MS/MS) methodology, applicable to both hydrophilic or more hydrophobic peptides, which was utilized to analyze a total of 10 putative cognitive enhancing polypeptides, with variable biochemical characteristics, that are currently being sold online. The screening rationale, complying to the recommendation paper of the General European Official Medicines Control Laboratory (OMCL) network on the interpretation of screening results for unknown peptides by mass spectrometry, was also validated in different matrices as required by ISO 17025.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.