SARS-CoV-2 Receptor-Binding Domain IgG Response to AstraZeneca (AZD1222) COVID-19 Vaccination, Jamaica

The Caribbean region is lacking an assessment of the antibody response and side effects experienced after AstraZeneca COVID-19 vaccination (AZD1222). We examined severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike receptor-binding domain (RBD) IgG levels and report the side effects noted in a Jamaican population after AZD1222 vaccination. Median RBD IgG levels for persons without evidence of previous SARS-CoV-2 infection were 43.1 binding international units (bIU)/mL 3 to 7 weeks after the first dose, increasing to 100.1 bIU/mL 3 to 7 weeks after the second dose, and decreasing to 46.9 bIU/mL 16 to 22 weeks after the second dose. The median RBD IgG level 2 to 8 weeks after symptom onset for unvaccinated SARS-CoV-2-infected persons of all disease severities was 411.6 bIU/mL. Common AZD1222 side effects after the first dose were injection site pain, headache, and chills. Most people reported no side effects after the second dose. AZD1222 is widely used across the English-speaking Caribbean, and our study provides evidence for its continued safe and effective use in vaccination programs.