Vaccination strategy and anti - SARS-CoV-2 S titers in healthcare workers of the INT – IRCCS “Fondazione Pascale” Cancer Center (Naples, Italy)

Abstract

Background Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection and the resulting disease, coronavirus disease 2019 (COVID-19), have spread to millions of people globally, requiring the development of billions of different vaccine doses. The SARS-CoV-2 spike mRNA vaccine (named BNT162b2/Pfizer), authorized by the FDA, has shown high efficacy in preventing SARS-CoV-2 infection after administration of two doses in individuals 16 years of age and older. In the present study, we retrospectively evaluated the differences in the SARS-CoV-2 humoral immune response after vaccine administration in the two different cohorts of workers at the INT - IRCCS “Fondazione Pascale” Cancer Center (Naples, Italy): previously infected to SARS-CoV-2 subjects and not infected to SARS-CoV-2 subjects. Methods We determined specific anti-RBD (receptor-binding domain) titers against trimeric spike glycoprotein (S) of SARS-CoV-2 by Roche Elecsys Anti-SARS-CoV-2 S immunoassay in serum samples of 35 healthcare workers with a previous documented history of SARS-CoV-2 infection and 158 healthcare workers without, after 1 and 2 doses of vaccine, respectively. Moreover, geometric mean titers and relative fold changes (FC) were calculated. Results Both previously infected and not infected to SARS-CoV-2 subjects developed significant immune responses to SARS-CoV-2 after the administration of 1 and 2 doses of vaccine, respectively. Anti-S antibody responses to the first dose of vaccine were significantly higher in previously SARS-CoV-2-infected subjects in comparison to titers of not infected subjects after the first as well as the second dose of vaccine. Fold changes for subjects previously infected to SARS-CoV-2 was very modest, given the high basal antibody titer, as well as the upper limit of 2500.0 BAU/mL imposed by the Roche methods. Conversely, for naïve subjects, mean fold change following the first dose was low ($$ \overline{x} $$ x ¯ =1.6), reaching 3.8 FC in 72 subjects (45.6%) following the second dose. Conclusions The results showed that, as early as the first dose, SARS-CoV-2-infected individuals developed a remarkable and statistically significant immune response in comparison to those who did not contract the virus previously, suggesting the possibility of administering only one dose in previously SARS-CoV-2-infected subjects. FC for previously infected subjects should not be taken into account for the generally high pre-vaccination values. Conversely, FC for not infected subjects, after the second dose, were = 3.8 in > 45.0% of vaccinees, and ≤ 3.1 in 19.0%, the latter showing a potential susceptibility to further SARS-CoV-2 infection.

Safety and antibody response to two-dose SARS-CoV-2 messenger RNA vaccination in patients with multiple myeloma

“…While high immunogenicity in MM patients is promising, clinical trials in the general population reported a 100% seroconversion rate for both vaccine types [ 3 , 4 ]. Median antibody titers in immunocompetent populations in response to the vaccine measured by the same assay used in this study have been found to be > 250 U/mL [ 13 , 14 ]. Of note, the only participant on teclistamab did not develop an antibody response.…”

Use of Quantitative Dried Blood Spots to Evaluate the Post-Vaccination Level of Neutralizing Antibodies against SARS-CoV-2

“…In addition, these analyzers are already present in many clinics and hospitals worldwide for diagnostic tests. The Roche Elecsys anti-SARS-CoV-2 S assay was also demonstrated to be a reliable assay to confirm recent COVID infections [26] and was proposed as a useful tool to evaluate the need for one or two vaccine doses in the case of pre-existing anti-SARS-CoV-2 antibodies, the purpose being to limit potential adverse effects [27]. Higher titers are indeed detected in people with a previous SARS-CoV-2 infection and also those who have been vaccinated compared to people without previous exposure to the virus: a median value of 30,527 U/mL in plasma for recovered COVID-19 patients versus a median value of 1975 U/mL in COVID-19 negative people 10 days post-vaccination [8].…”

Bimodal Antibody-Titer Decline Following BNT162b2 Mrna Anti-SARS-Cov-2 Vaccination In Healthcare Workers of The INT – IRCCS “Fondazione Pascale” Cancer Center (Naples, Italy)

“…On 22 nd December 2020, the Italian regulatory agency for drugs AIFA (Agenzia Italiana del Farmaco) authorized in Italy the use of BNT162b2/P zer vaccine, in 2 doses with an interval of 21 days between the doses [10]. Recent studies have found that subjects infected with COVID-19 develop higher antibody titers after vaccination [11] and present protective immunity for at least 6 months [12], but the impact of previous exposure to SARS-CoV-2 on immune response elicited by the vaccines needs to be further veri ed in larger trial studies. Several studies have shown that the immune response to the vaccine after the rst dose is substantially more pronounced in individuals with pre-existing immunity and it is similar to the immune response developed after the second dose in individuals not previously infected [11,13,14,15].…”

“…Recent studies have found that subjects infected with COVID-19 develop higher antibody titers after vaccination [11] and present protective immunity for at least 6 months [12], but the impact of previous exposure to SARS-CoV-2 on immune response elicited by the vaccines needs to be further veri ed in larger trial studies. Several studies have shown that the immune response to the vaccine after the rst dose is substantially more pronounced in individuals with pre-existing immunity and it is similar to the immune response developed after the second dose in individuals not previously infected [11,13,14,15]. However, few data are available on the accurate monitoring of the titers' decline, response to further boosters, optimal vaccine dosage and role of different adjuvants on vaccine e cacy.…”