Using national COVID-19 notification, hospitalisation, and vaccination datasets from Brazil, we did a testnegative, case-control study to assess the effectiveness of four vaccines (CoronaVac [Sinovac], ChAdOx1 nCoV-19 [AstraZeneca], Ad26.COV2.S [Janssen], and BNT162b2 [Pfizer-BioNtech]) for individuals with laboratory-confirmed previous SARS-CoV-2 infection. We matched cases with RT-PCR positive, symptomatic COVID-19 with up to ten controls with negative RT-PCR tests who presented with symptomatic illnesses, restricting both groups to tests done at least 90 days after an initial infection. We used multivariable conditional logistic regression to compare the odds of test positivity and the odds of hospitalisation or death due to COVID-19, according to vaccination status and time since first or second dose of vaccines.

16th May 2022 • comment

In this report, the authors assessed the number of childhood and adolescent vaccinations administered in the months before and after the start of the COVID-19 outbreak in Colorado. Findings suggest that since the onset of the COVID-19 pandemic, vaccination uptake in children and adolescents has shown a significant decrease in Colorado. While the clinical implications of our observation are not yet known, public health advocates should consider addressing this drop to avoid the potential for vaccine-preventable diseases.

14th December 2020 • comment