Fig 1.
Flowcharts showing inclusion and exclusion criteria for nested case-control studies within the HEROES/RECOVER cohort of frontline workers: 613 cases of first-time post-vaccination infection following a third dose of COVID-19 origin strain WA-1 monovalent mRNA vaccine were matched 1:1 to controls based on site and time between vaccination and blood draw.
Fig 2.
Flowcharts showing inclusion and exclusion criteria for nested case-control studies within the HEROES/RECOVER cohort of frontline workers: 350 cases of reinfection were matched 1:1 to controls based on site, vaccination status, variant of first infection, and time between immune conferring event (either vaccine or infection) and blood draw.
Table 1.
Demographic and health characteristics for nested case-control samples within the HEROES/RECOVER prospective cohort of frontline workers: the first-time post-vaccination sample was matched by site and days between booster vaccine and blood draw, and the reinfection sample was matched on site, vaccination status, variant of first infection, and days between most recent immune conferring event and blood draw.
Table 2.
Quantitative antibody results, including end titers and area under the curve (AUC) calculations for SARS-CoV-2 receptor-binding domain (RBD) and (S2) spike protein subunits in nested case-control samples from the HEROES/RECOVER prospective cohort of frontline workers.
Fig 3.
Adjusted relative risk reduction for first-time post-vaccination infection with Omicron following a third dose of an origin strain WA-1 monovalent mRNA COVID-19 vaccine among frontline workers in the HEROES/RECOVER cohort with 95% confidence intervals using an end titer level of 1:60 as the reference.
Samples where antibody response was still detected at the final dilution were imputed to 1:9720. The estimated percent reduction was 50% near the 1:1620 dilution for RBD and between the 1:540 and 1:1620 dilution for S2.
Table 3.
Unadjusted and adjusted odds ratios (ORs) generated by conditional logistic regression models for a nested sample of individuals with first-time post-vaccination infection following third COVID-19 origin strain WA-1 monovalent mRNA vaccine dose and matched controls (n = 1226) and for a nested sample of individuals with reinfection and matched controls, stratified by vaccination status (n = 700) from the HEROES/RECOVER prospective cohort of frontline workers.
Fig 4.
Adjusted relative risk reduction in reinfection with Omicron among frontline workers in the HEROES/RECOVER cohort infection by humoral antibody titer levels with 95% confidence intervalsa using end titer level of 1:60 as the reference and stratified by number of origin strain WA-1 monovalent mRNA COVID-19 vaccine doses.
Samples where antibody response was still detected at the final dilution were imputed to 1:9720. Among unvaccinated individuals, the estimated percent reduction was 50% between the 1:540 and 1:1620 dilution for RBD. Among individuals with 3 prior COVID-19 vaccine doses, the estimated percent reduction was 50% between the 1:60 and 1:180 dilution. a95% confidence interval only available for models with a statistically significant coefficient for end titer when alpha is 0.05.