A Longitudinal Study of BNT162b2 Vaccine-Induced Humoral Response and Reactogenicity in Health Care Workers with Prior COVID-19 Disease

Abstract

BackgroundThe SARS–CoV–2 mRNA vaccines now available are highly effective at preventing infection and afford the prospect of an end to the pandemic. Vaccines are in scare supply, however. Current recommendations in the United States are that subjects with a previous history of SARS CoV-2 infection/COVID-19 disease should receive the full vaccine regimen. This is despite the fact that prior SARS-CoV-2 infection infection confers some degree of protection and that the immune response to the vaccine is not well studied.MethodsThe present study compared the time course and magnitude of the humoral immune response to an mRNA SARS-CoV-2 vaccine (BNT162b2) in subjects with prior infection/COVID-19 disease (n=24) and those without prior infection (n=25). Serum anti-Spike RBD antibody and serum neutralizing activity were assessed longitudinally prior to and at 2-week intervals for 56 days post first dose of vaccine. Subjects received the standard Pfizer BNT162b2 mRNA vaccine regimen i.e., two doses of 30 µg, 3 weeks apart.FindingsThe cohort with prior COVID-19 achieved robust increases in anti-Spike IgG antibody and serum neutralizing activity compared to the SARS–CoV-2 naïve cohort at day 14 post vaccine. Thereafter, the COVID-19 cohort showed relatively little further increase in humoral immunity even after the second dose such that anti-Spike IgG and neutralizing activity were similar in the 2 groups from day 28 through day 56.ConclusionsIn contrast to the responses of SARS–CoV-2 naïve subjects in whom a 2 dose regimen appears to be required to achieve robust immune protection, subjects with prior SARS–CoV-2 infection exhibit immune memory and have a robust response to the first dose of an mRNA vaccine. They may require only a single dose of vaccine.

Effects of age, sex, serostatus, and underlying comorbidities on humoral response post-SARS-CoV-2 Pfizer-BioNTech mRNA vaccination: a systematic review

“…In three separate studies, baseline antibody titers of seropositive individuals were multiple folds higher than of seronegative subjects after the second vaccine dose [ 12 , 17 , 24 ]. On the other hand, some publications stated that there was no significant difference between these two groups after the second dose [ 16 , 19 , 21 ]. As a result, different recommendations can be gathered from different sources.…”

Effects of Age, Sex, Serostatus and Underlying Comorbidities on Humoral Response Post-SARS-CoV-2 Pfizer-BioNTech Vaccination – A Systematic Review

“…In two separate studies, antibody titers of seropositive individuals are multiple folds higher than those baseline seronegative subjects after the second vaccine dose [17,26]. On the other hand, some publications stated that there is no significant difference between the two groups after the second dose [27,28,29]. As a result, different recommendations can be gathered from different sources.…”

“…Kelsen et al . recommended that subjects with prior COVID-19 may require only a single dose of vaccine [29], and eventually a second dose only when the antibody levels decline significantly ( i . e ., typically, after 12 months), or in case new VBM and VoC, characterized by the so-called “escape mutations”, become endemic.…”

“…As a result, different recommendations can be gathered from different sources. Kelsen et al recommended that subjects with prior COVID-19 may require only a single dose of vaccine [29], and eventually a second dose only when the antibody levels decline significantly (i.e., typically, after 12 months), or in case new VBM and VoC, characterized by the so-called "escape mutations", become endemic. This is in contrast with the recommendation of Demonbreun et al stating that one vaccine is not enough to produce strong protection against SARS-CoV-2 infection among most people previously infected [30].…”

Characterization of the significant decline in humoral immune response six months post-SARS-CoV-2 mRNA vaccination: A systematic review

“…Some studies reported that seropositive groups continue to have increased Ab levels compared to seronegative groups, while others reported that there is no significant difference between the two groups. [37][38][39][40][41][42] These disparities in trend are conveyed in the rate of decline of Ab titers at 5-6 months after full immunization compared to peak levels. Among the four journal articles included in this study, two reported that seropositive groups had a larger percent decline in Ab titers from peak compared with seronegative groups.…”