Anti-SARS-CoV-2 IgG against the S Protein: A Comparison of BNT162b2, mRNA-1273, ChAdOx1 nCoV-2019 and Ad26.COV2.S Vaccines

Abstract

Background: COVID-19 vaccines induce a differentiated humoral and cellular response, and one of the comparable parameters of the vaccine response is the determination of IgG antibodies. Materials and Methods: Concentrations of IgG anti-SARS-CoV-2 antibodies were analyzed at three time points (at the beginning of May, at the end of June and at the end of September). Serum samples were obtained from 954 employees of the Nicolaus Copernicus University in Toruń (a total of three samples each were obtained from 511 vaccinated participants). IgG antibody concentrations were determined by enzyme immunoassay. The statistical analysis included comparisons between vaccines, between convalescents and COVID-19 non-patients, between individual measurements and included the gender, age and blood groups of participants. Results: There were significant differences in antibody levels between mRNA and vector vaccines. People vaccinated with mRNA-1273 achieved the highest levels of antibodies, regardless of the time since full vaccination. People vaccinated with ChAdOx1 nCoV-2019 produced several times lower antibody levels compared to the mRNA vaccines, while the antibody levels were more stable. In the case of each of the vaccines, the factor having the strongest impact on the level and stability of the IgG antibody titers was previous SARS-CoV-2 infection. There were no significant correlations with age, gender and blood type. Summary: mRNA vaccines induce a stronger humoral response of the immune system with the fastest loss of antibodies over time.

Humoral Immune Response Diversity to Different COVID-19 Vaccines: Implications for the “Green Pass” Policy

“…Moreover, according to Szczepanek et al. ( 33 ), our data confirmed that natural COVID-19 infection combined with vaccination results, on average, in higher antibody titer and higher neutralizing activity with respect to fully vaccinated individuals without prior COVID-19, as reported elsewhere ( 35 ). Next, we investigated the correlation between total anti-RBD antibody and neutralizing capacity, finding that the concentration of serum antibodies against Spike is partially correlated with ACE2-RBD binding inhibition, as sera with lower antibody titer could show similar neutralizing activity to that observed in sera with higher antibody titer, consistently with previous reports ( 36 ).…”

“…Indeed, whereas a high anti-RBD antibody titer implies a higher probability of having an effective neutralizing activity, we could see a remarkable association between the type of vaccine and the related serum neutralizing antibodies, with mRNA-based vaccines being overall more capable of producing antibody-mediated inhibiting activity respect to adenoviral DNA-based vaccines, as also reported by Szczepanek et al. ( 33 ). Together with the ELISA-based qualitative assessment of peptide reactogenicity in sera from study participants, our data show that the polyclonal response to vaccination confers different levels of protection and that the neutralizing activity cannot be recapitulated by the measurement of serum antibodies against Spike-RBD alone, in contrast with previous findings ( 37 ).…”

“…Indeed, while this manuscript was in peer-reviewing, Szczepanek et al. ( 33 ) have described substantial differences in the anti-Spike IgG levels from a cohort of 511 individuals vaccinated with mRNA-1273, BNT162b2, Ad26.COV2.S, and ChAdOx1 nCoV-19. Our study shows that all four approved vaccines in the European community are effective in stimulating a humoral response against SARS-CoV-2 Spike, and, as already reported ( 34 ), the magnitude of the total anti-RBD antibody decreases with age.…”

Analysis of immunization time, amplitude, and adverse events of seven different vaccines against SARS-CoV-2 across four different countries

“…Our study found that the previous history of SARS-CoV-2 was related to an increase in change in antibody levels, as confirmed elsewhere (12). Also, we found higher levels in antibodies in older patients when they had previous SARS-CoV-2 infection and received Gam-COVID Vac or ChAdOx1-S.…”

“…The greatest change in antibody levels occurred with mRNA-1273, followed by BNT162b2 mRNA and Gam-COVID-Vac. Previous studies have shown a greater change in antibody titers for mRNA vector vaccines (12)(13)(14).…”