Effect of COVID-19 on Anti-S Antibody Response in Healthcare Workers Six Months Post-Vaccination

Abstract

The current study aimed to determine to what extent prior COVID-19 infection affects the response of specific antibodies following vaccination. The study involved 173 healthcare professionals who completed the two-dose vaccination course with BNT162b2, including 40 who previously experienced clinical COVID-19. The levels of anti-SARS-CoV-2 S1S2 IgG (anti-S) and, in some cases, anti-SARS-CoV-S-RBD IgG (anti-S-RBD) were determined six months after complete vaccination. A level exceeding the cut-off values for both anti-S and anti-S-RBD was observed in 100% of subjects, but after setting the analysis to 5- and 10-fold cut-off levels, the percentage of subjects meeting this criterion was significantly higher for anti-S-RBD. The 100-fold cut-off level was achieved by only 21% and 16% for anti-S and anti-S-RBD, respectively. Anti-S and anti-S-RBD levels above ten times the positive cut-off were respectively observed in 91% and 100% individuals with a history of COVID-19, while among those without COVID-19, these values were 64% and 90%, respectively. Significantly higher incidence of values above 10 and 100 times the cut-off became apparent among people with a history of COVID-19. In conclusion, vaccination against COVID-19 following infection with the disease provides higher levels of specific antibodies 6 months after vaccination than those of individuals without a history of the disease, which supports the use of a booster dose, particularly for those who have not experienced SARS-CoV-2 infection.

Decline of Anti-SARS-CoV-2 IgG Antibody Levels 6 Months after Complete BNT162b2 Vaccination in Healthcare Workers to Levels Observed Following the First Vaccine Dose

“…One dose of vaccine received after COVID-19 is sufficient to produce peak antibody levels extremely quickly. These findings agree with the results of previous studies and go in line with the recommendation of second dose administration 6 months after recovering from COVID-19 [14][15][16][17][18][19][20][21][22][23][24][25][27][28][29][30]. Furthermore, these results can be explained by the limited humoral response to SARS-CoV-2 and the self-maintenance nature of the immune system.…”

“…While IgG antibodies can be detected in a vast majority of COVID-19 patients 10 days after the infection, their levels generally decrease over time [4][5][6][7]. Similar patterns in antibody dynamics could be predicted after vaccination [15][16][17][18][19][20][21]. Post-COVID-19 specific antibodies are directed toward different antigens, such as the nucleoprotein (NP) and spike (S) antigens.…”

Immunogenicity evaluation after BNT162b2 booster vaccination in healthcare workers

“…In Finland, mRNA vaccine displayed only 53% from the initial IgG level after 6 months, but antibody waning was not observed against COVID-19 hospitalization 28 . In a HCW Polish cohort it was reported that there are higher levels of specific antibodies 6 months after vaccination in subjects experiencing the disease after the first round of vaccination, the finding supporting once more the use of a booster dose, especially for non-infected subjects 29 .…”

Antibody responses to mRNA versus non-mRNA COVID vaccines among the Mongolian population

“…In a cohort analysis of SARS-CoV-2 anti-S-RBD IgG levels and neutralizing antibodies in fully vaccinated healthcare workers, the concentration of anti-RBD and anti-S antibodies was increased in individuals who received the full dose of Pfizer/BioNTech vaccine [19] . A study involving healthcare professionals who received two doses of BNT162b2 vaccine showed increased levels of anti-SARS-CoV-2 S1S2 IgG and anti-SARS-CoV-2 S-RBD IgG at 6 months after vaccination [20] . Firinu et al.…”