Six-month follow-up post-third dose of vaccine
infections
MALIGNANCIES, INFECTIONS, HEMATOLOGIC MALIGNANCIES, BREAKTHROUGH SARS-COV-2 INFECTION
Forty-seven patients (44%) out of 106 completed 4–6 months’ follow-up for the third dose study. All these patients were seropositive 4 weeks after the third dose and strikingly, we observed that all patients maintained a positive anti-S antibody at 4–6 months’ follow-up. Eleven of these 47 patients had solid malignancies and 36 had hematologic malignancies. Six patients had received anti-COVID monoclonal antibody (moAb) therapy as per standard of care (4 tixagevimab-cilgavimab or Evusheld, 1 casirivimab/imdevimab or regen-co-v, and 1 sotrovimab between the 4 week and 4–6 months’ follow-up). A striking increase in titers in this small cohort of patients was noted to a median titer of 17481.2 AU/mL. Four patients had breakthrough SARS-CoV-2 infections and 9 patients had received a fourth dose of COVID-19 vaccine outside of the context of the study prior to the time of 4–6 months’ follow-up. Of the four breakthrough infections, one patient had no symptoms and three had mild symptoms.The median decline in titer for 41 patients who did not receive anti-SARS-CoV-2 (anti-S) moAb treatment in the interim to confound results was –922.2 AU/mL. When compared to the antibody levels 4 weeks after booster vaccination, the median percentage decline in titers was 56.4%. However, despite the noted decline not a single patient in this cohort seroreverted (