Effectiveness of a Nationwide COVID-19 Vaccination Program in Mexico Against Symptomatic COVID-19, Hospitalizations, and Death: a Retrospective Analysis of National Surveillance Data

Objectives: Vaccination has been effective in ameliorating the impact of COVID-19. Here, we report vac-cine effectiveness (VE) of the nationally available COVID-19 vaccines in Mexico. Methods: Retrospective analysis of a COVID-19 surveillance system to assess the VE of the BNT162b2, messenger RNA (mRNA)-12732, Gam-COVID-Vac, Ad5-nCoV, Ad26.COV2.S, ChAdOx1, and CoronaVac vac-cines against SARS-CoV-2 infection, COVID-19 hospitalization, and death in Mexico. The VE was estimated using time-varying Cox proportional hazard models in vaccinated and unvaccinated adults, adjusted for age, sex, and comorbidities. VE was also estimated for adults with diabetes, aged >= 60 years, and compar-ing the predominance of SARS-CoV-2 variants B.1.1.519 and B.1.617.2. Results: We assessed 793,487 vaccinated and 4,792,338 unvaccinated adults between December 24, 2020 and September 27, 2021. The VE against SARS-CoV-2 infection was the highest for fully vaccinated indi-viduals with mRNA-12732 (91.5%, 95% confidence interval ICI] 90.3-92.4) and Ad26.COV2.S (82.2%, 95% CI 81.4-82.9); for COVID-19 hospitalization, BNT162b2 (84.3%, 95% CI 83.6-84.9) and Gam-COVID-Vac (81.4% 95% CI 79.5-83.1), and for mortality, BNT162b2 (89.8%, 95% CI 89.2-90.2) and mRNA-12732 (93.5%, 95% CI 86.0-97.0). The VE decreased for all vaccines in adults aged >= 60 years, people with diabetes, and periods of Delta variant predominance.