Anti-SARS-CoV-2 Immunoglobulin Isotypes, and Neutralization Activity Against Viral Variants, According to BNT162b2-Vaccination and Infection History

Abstract

PurposeTo compare SARS-CoV-2 antigen-specific antibody production and plasma neutralizing capacity against B.1 wild-type-like strain, and Gamma/P.1 and Delta/B.1.617.2 variants-of-concern, in subjects with different Covid-19 disease and vaccination histories.MethodsAdult subjects were: 1) Unvaccinated/hospitalized for Covid-19; 2) Covid-19-recovered followed by one BNT162b2 vaccine dose; and 3) Covid-19-naïve/2-dose BNT162b2 vaccinated. Multiplex Luminex® immunoassays measured IgG, IgA, and IgM plasma levels against SARS-CoV-2 receptor-binding domain (RBD), spike-1 (S), and nucleocapsid proteins. Neutralizing activity was determined in Vero E6 cytopathic assays.ResultsMaximum anti-RBD IgG levels were similar in Covid-19‑recovered individuals 8‒10 days after single-dose vaccination and in Covid-19-naïve subjects 7 days after 2nd vaccine dosing; both groups had ≈2‑fold higher anti-RBD IgG levels than Unvaccinated/Covid-19 subjects tracked through 2 weeks post-symptom onset. Anti-S IgG expression patterns were similar to RBD within each group, but with lower signal strengths. Viral antigen-specific IgA and IgM levels were more variable than IgG patterns. Anti-nucleocapsid immunoglobulins were not detected in Covid-19-naïve subjects. Neutralizing activity against the B.1 strain, and Gamma/P.1 and Delta/B.1.617.2 variants, was highest in Covid‑19-recovered/single-dose vaccinated subjects; although neutralization against the Delta variant in this group was only 26% compared to B.1 neutralization, absolute anti-Delta titers suggested maintained protection. Neutralizing titers against the Gamma and Delta variants were 33‒77% and 26‒67%, respectively, versus neutralization against the B.1 strain (100%) in the three groups.ConclusionThese findings support SARS-CoV-2 mRNA vaccine usefulness regardless of Covid-19 history, and confirm remarkable protection provided by a single vaccine dose in people who have recovered from Covid-19.

SARS-CoV-2 seroprevalence and antibodies persistence among health care workers after the first COVID-19 wave in nine hospitals in Western France

“…Finally, the association that was observed with performing upper respiratory tract samples performed from a COVID-19 patient could be explained as a result of exposure to aerosolization [11] . Levels of SARS-CoV-2 antibodies decreased between day 0 and day 90, in line with previous reports [12] , [13] , [14] , [15] , [16] . Although several factors were associated with higher levels of total neutralizing antibodies such as symptom severity [12] , [13] , [15] , older age, and gender, results concerning factors associated with the level of total anti-nucleocapsid antibodies raised little interest to date, and may be different.…”

Durability of Humoral Responses after the Second Dose of mRNA BNT162b2 Vaccine in Residents of a Long Term Care Facility

“…Notably, median titers of anti-S IgG were considerably lower in the entire population, indicating a fast decay of response, which is in agreement with previous reports [18,28,29]. Overall, our studies confirm the accumulating evidence [14,[30][31][32] that long term humoral response and vaccine effectiveness in previously infected persons were superior to that in recipients who did not experience COVID-19 and received two doses of the vaccine [33]. By analyzing residents with or without previous COVID-19 infection, we demonstrated that median levels of specific antibody levels significantly decreased in the latter population over time, displaying titer values at least 10 times lower compared to the formers.…”

Neutralizing Antibody Activity Against the B.1.617.2 (delta) Variant Before and After a Third BNT162b2 Vaccine Dose in Hemodialysis Patients

“…Recently, the importance of IgA in neutralization of SARS-CoV-2 has been described in patients with COVID-19 infection (43,44). Sterlin (45). Anti-RBD and anti-S1 IgA were also significantly elevated in participants after BNT162b2 vaccination, but patterns were more variable than IgG patterns (45).…”

“…Sterlin (45). Anti-RBD and anti-S1 IgA were also significantly elevated in participants after BNT162b2 vaccination, but patterns were more variable than IgG patterns (45). Different studies suggest the development of vaccines that target a potent specific respiratory IgA response to SARS-CoV-2 (14,43,44,46).…”