Effectiveness of a nation-wide COVID-19 vaccination program in Mexico

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Abstract

BACKGROUND

Vaccination has been effective in ameliorating the impact of COVID-19. However, estimation of vaccine effectiveness (VE) is still unavailable for some widely used vaccines and underrepresented groups. Here, we report on the effectiveness of a nation-wide COVID-19 vaccination program in Mexico.

METHODS

We used a test-negative design within a national COVID-19 surveillance system to assess VE of the BNT162b2, mRNA-12732, Gam-COVID-Vac, Ad5-nCoV, Ad26.COV2.S, ChAdOx1 and CoronaVac vaccines, against SARS-CoV-2 infection, COVID-19 related hospitalization and death for adults ≥18 years in Mexico. VE was estimated using Cox proportional hazard models considering time-varying vaccination status in partial and fully vaccinated individuals compared to unvaccinated adults, adjusted by age, sex, comorbidities and municipality. We also estimated VE for adults ≥60 years, for cases with diabetes and comparing periods with predominance of variants B.1.1.519 and B.1.617.2.

RESULTS

We assessed 793,487 vaccinated compared to 4,792,338 unvaccinated adults between December 24 th , 2020, and September 27 th , 2021. VE against SARS-CoV-2 infection was highest for fully vaccinated individuals with mRNA-12732 (91.5%, 95%CI 90.3-92.4) and Ad26.COV2.S (82.2%, 95%CI 81.4-82.9), whereas for COVID-19 related hospitalization were 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). VE for all evaluated vaccines was reduced for adults ≥60 years, people with diabetes, and in periods of Delta variant predominance.

CONCLUSIONS

All evaluated vaccines were effective against SARS-CoV-2 infection and COVID-19 related hospitalization and death. Mass vaccination campaigns with multiple vaccine products are feasible and effective to maximize vaccination coverage.

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  1. SciScore for 10.1101/2022.04.04.22273330: (What is this?)

    Please note, not all rigor criteria are appropriate for all manuscripts.

    Table 1: Rigor

    NIH rigor criteria are not applicable to paper type.

    Table 2: Resources

    No key resources detected.


    Results from OddPub: Thank you for sharing your code and data.


    Results from LimitationRecognizer: We detected the following sentences addressing limitations in the study:
    Our study had some strengths and limitations. Amongst the strengths we highlight the use of a nation-wide surveillance system to monitor SARS-CoV-2 infections which can capture dynamics of COVID-19 transmission at the municipal level, allowing for evaluation of vaccination status and clinical follow-up of all suspected, confirmed, and negative COVID-19 cases in Mexico within the SISVER registry. This allowed us to evaluate three relevant outcomes for VE, including SARS-CoV-2 infection, and COVID-19 related hospitalization and death at a national level27. Furthermore, by evaluating a national vaccination campaign which incorporated multiple vaccines we were able to assess the feasibility of incorporating multiple vaccines simultaneously to maximize vaccination coverage, which will also be helpful when evaluating policies to implement heterologous schemes for vaccine boosters in the future. Finally, by incorporating a time-varying component to the vaccination status, we were able to capture shifts in exposure risks through the follow-up time to allow for more precise estimates of vaccine effectiveness for all evaluated outcomes. We would also like to acknowledge some limitations which should be considered to adequately interpret our results. First, the SISVER dataset is a sentinel surveillance system, which is designed to evaluate high-risk symptomatic cases which are assessed and tested for COVID-1931; because of its design, SISVER primarily identifies cases with moderate to s...

    Results from TrialIdentifier: No clinical trial numbers were referenced.


    Results from Barzooka: We did not find any issues relating to the usage of bar graphs.


    Results from JetFighter: We did not find any issues relating to colormaps.


    Results from rtransparent:
    • Thank you for including a conflict of interest statement. Authors are encouraged to include this statement when submitting to a journal.
    • Thank you for including a funding statement. Authors are encouraged to include this statement when submitting to a journal.
    • No protocol registration statement was detected.

    Results from scite Reference Check: We found no unreliable references.


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