Comparison of the effectiveness of four SARS-COV-2 v accines in Nuevo Leon, Mexico: A test-negative control study.

OBJECTIVE

The objective of the present study was to provide statewide estimates of real-world effectiveness in reducing the odds of one primary (symptomatic COVID-19 infection) and two secondary outcomes (hospitalization and severe COVID-19 infection) by four vaccines BNT162b2 (Pfizer-BioNTech), ChAdOx1 (AstraZeneca), Ad5-nCoV (CanSinoBIO), and CoronaVac (Sinovac Life Sciences), used in Northeast Mexico.

DESIGN

We conducted a test-negative case-control study and analyzed statewide surveillance data from December 2020 to August 2021. SITE: Primary attention and hospitalization.

PARTICIPANTS

Two inclusion criteria were applied, age≥18 years and having a real-time reverse-transcriptase-polymerase-chain-reaction assay or a rapid test for antigen detection in postnasal samples (N=164,052). The vaccination was considered complete if at least 14 days had passed since the application of the single or second dose and the beginning of symptomatology.

INTERVENTIONS

Does not apply.

MAIN MEASUREMENTS

Point and 95% confidence intervals (CI) of vaccine effectiveness were calculated per type of vaccine using the formula 1 - odds ratio, adjusted by sex and age.

RESULTS

Complete vaccination offered from none (CoronaVac - Sinovac) to 75% (95%CI 71, 77) (BNT162b2 - Pfizer) effectiveness in reducing symptomatic COVID-19 infection, regardless of sex and age. The fully ChAdOx1 (AstraZeneca) scheme reached the maximum effectiveness in hospitalization (80%, 95%CI 69, 87) and the fully BNT162b2 (Pfizer) scheme the maximum effectiveness in severity (81%, 95%CI 64, 90).

CONCLUSIONS

More studies are needed to compare benefits of different vaccines and guide policy makers select the best option for their population.