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Immunogenicity of bivalent versus monovalent mRNA booster vaccination among adult paramedics in Canada who had received three prior mRNA wild-type doses
Introduction. Comparative immunogenicity from different mRNA booster vaccines (directed at WT BA.1 or BA.4/5 antigens) remains unclear.
Methods. We included blood samples from adult paramedics who received three mRNA WT-directed vaccines plus a fourth dose of the following: (1) WT monovalent (2) Moderna BA.1-WT bivalent or (3) Pfizer BA.4/5 WT bivalent vaccine. The primary outcome was angiotensin-converting enzyme 2 (ACE2) inhibition to BA.4/5 antigen. We used optimal pair matching (using age sex-at-birth preceding SARS-CoV-2 infection and fourth vaccine-to-blood collection interval) to create balanced groups to individually compare each vaccine type to each other vaccine (overall within subgroups defined by SARS-CoV-2 infection and after combining BA.1 and BA.4/5 cases). We compared outcomes with the Wilcoxon matched-pairs signed rank test.
Results. Overall 158 paramedics (mean age 45 years) were included. ACE2 inhibition was higher for BA.1 compared to WT (P=0.002); however no difference was detected between BA.4/5 vs. WT or BA.1 vs. BA.4/5. Among cases with preceding SARS-CoV-2 there were no detected between-group differences. Among cases without preceding SARS-CoV-2 the only detected difference was BA.1>WT (P=0.003). BA.1 and BA.4/5 cases combined had higher ACE2 inhibition than WT (P=0.003).
Conclusion. Omicron-directed vaccines appear to improve Omicron-specific immunogenicity; however this appears limited to SARS-CoV-2-naive individuals.
Preprint: Immunogenicity of bivalent versus monovalent mRNA booster vaccination among adult paramedics in Canada who had received three prior mRNA wild-type doses
Introduction: Comparative immunogenicity from different mRNA booster vaccines (directed at wild-type [WT] BA.1 or BA.4/5 antigens) remains unclear.
Methods: We included blood samples from adult paramedics who received three mRNA WT-directed vaccines plus a fourth dose of: (1) WT monovalent; (2) Moderna BA.1-WT bivalent; or (3) Pfizer BA.4/5-WT bivalent vaccine. The primary outcome was angiotensin-converting enzyme 2 (ACE-2) inhibition to BA.4/5 antigen. We used optimal pair matching (using age sex-at-birth preceding SARS-CoV-2 infection and fourth vaccine-to-blood collection interval) to create balanced groups to individually compare each vaccine type to each other vaccine (overall within subgroups defined by SARS-CoV-2 infection and after combining BA.1 and BA.4/5 cases). We compared outcomes with Wilcoxon matched pairs signed rank test.
Results: Overall 158 paramedics (mean age 45 years) were included. ACE-2 inhibition was higher for BA.1 compared to WT (p=0.002); however no difference was detected between BA.4/5 vs. WT or BA.1 vs BA.4/5. Among cases with preceding SARS-CoV-2 there were no between-group differences. Among cases without preceding SARS-CoV-2 the only difference was BA.1 > WT (p=0.003). BA.1 and BA.4/5 cases combined had higher ACE2 inhibition than WT (p = 0.003).
Conclusion: Omicron-directed vaccines appear to improve Omicron-specific immunogenicity; however this appears limited to SARS-CoV-2-naïve individuals.
Preprint: The relationship between the number of COVID-19 vaccines and infection with Omicron ACE2 inhibition at 18-months post initial vaccination in an adult cohort of Canadian paramedics
The coronavirus disease 2019 (COVID-19) pandemic caused by the SARS-CoV-2 virus has rapidly evolved since late 2019 due to highly transmissible Omicron variants. While most Canadian paramedics have received COVID-19 vaccination the optimal ongoing vaccination strategy is unclear. We investigated neutralizing antibody (NtAb) response against wild-type (WT) Wuhan Hu-1 and Omicron BA.4/5 lineages based on the number of doses and past SARS-CoV-2 infection at 18 months post initial vaccination (with a Wuhan Hu-1 platform mRNA vaccine [BNT162b2 or mRNA-1273}). Demographic information previous COVID-19 vaccination infection history and blood samples were collected from paramedics 18 months post initial mRNA COVID-19 vaccine dose. Outcome measures were ACE2 percent inhibition against Omicron BA.4/5 and WT antigens. We compared outcomes based on number of vaccine doses (two vs. three) and previous SARS-CoV-2 infection status using the Mann-Whitney U test. Of 657 participants the median age was 40 years (IQR 33-50) and 251 (42%) were females. Overall median percent inhibition to BA.4/5 and WT was 71.61% (IQR 39.44-92.82) and 98.60% (IQR 83.07-99.73) respectively. Those with a past SARS-CoV-2 infection had a higher median percent inhibition to BA.4/5 and WT when compared to uninfected individuals overall and when stratified by two or three vaccine doses. When comparing two vs. three WT vaccine doses among SARS-CoV-2 negative participants we did not detect a difference in BA.4/5 percent inhibition but there was a difference in WT percent inhibition. Among those with previous SARS-CoV-2 infection(s) when comparing two vs. three WT vaccine doses there was no observed difference between groups. These findings demonstrate that additional Wuhan Hu-1 platform mRNA vaccines did not improve NtAb response to BA.4/5 but prior SARS-CoV-2 infection enhances NtAb response.
The relationship between the number of COVID-19 vaccines and infection with Omicron ACE2 inhibition at 18-months post initial vaccination in an adult cohort of Canadian paramedics
The coronavirus disease 2019 (COVID-19) pandemic caused by the SARS-CoV-2 virus has rapidly evolved since late 2019 due to highly transmissible Omicron variants. While most Canadian paramedics have received COVID-19 vaccination the optimal ongoing vaccination strategy is unclear. We investigated neutralizing antibody (NtAb) response against wild-type (WT) Wuhan Hu-1 and Omicron BA.4/5 lineages based on the number of doses and past SARS-CoV-2 infection at 18 months post-initial vaccination (with a Wuhan Hu-1 platform mRNA vaccine [BNT162b2 or mRNA-1273]). Demographic information previous COVID-19 vaccination infection history and blood samples were collected from paramedics 18 months post-initial mRNA COVID-19 vaccine dose. Outcome measures were ACE2 percent inhibition against Omicron BA.4/5 and WT antigens. We compared outcomes based on number of vaccine doses (two vs. three) and previous SARS-CoV-2 infection status using the Mann-Whitney U test. Of 657 participants the median age was 40 years (IQR 33–50) and 251 (42 %) were females. Overall median percent inhibition to BA.4/5 and WT was 71.61 % (IQR 39.44–92.82) and 98.60 % (IQR 83.07–99.73) respectively. Those with a past SARS-CoV-2 infection had a higher median percent inhibition to BA.4/5 and WT when compared to uninfected individuals overall and when stratified by two or three vaccine doses. When comparing two vs. three WT vaccine doses among SARS-CoV-2 negative participants we did not detect a difference in BA.4/5 percent inhibition but there was a difference in WT percent inhibition. Among those with previous SARS-CoV-2 infection(s) when comparing two vs. three WT vaccine doses there was no observed difference between groups. These findings demonstrate that additional Whttps://www.covid19immunitytaskforce.ca/citf-databank/#accessing https://www.covid19immunitytaskforce.ca/citf-databank/#accessinguhan Hu-1 platform mRNA vaccines did not improve NtAb response to BA.4/5 but prior SARS-CoV-2 infection enhances NtAb response.