Objectives To derive and validate risk prediction algorithms to estimate the risk of covid-19
related mortality and hospital admission in UK adults after one or two doses of covid-19 …

Objectives Rapid review to determine the magnitude of association between potential risk
factors and severity of COVID-19, to inform vaccine prioritisation in Canada. Setting Ovid …

Background: The BNT162b2 mRNA (Pfizer-BioNTech) and ChAdOx1 (Oxford-AstraZeneca)
COVID-19 vaccines have demonstrated high efficacy against infection in phase 3 clinical …

Objective To evaluate the impact of vaccine scale-up on population level covid-19 mortality
and incidence in the United States. Design Observational study. Setting US county level …

Non-randomised studies assessing COVID-19 vaccine effectiveness need to consider
multiple factors that may generate spurious estimates due to bias or genuinely modify …

Background Prior to the availability of vaccines, the risk factors for developing severe forms
of COVID-19 were mostly older age and various comorbidities such as diabetes …

Objective To investigate the effectiveness of primary covid-19 vaccination (first two doses
and first booster dose within the recommended schedule) against post-covid-19 condition …

Background: Whether vaccine effectiveness against Coronavirus disease 2019 (Covid-19)
lasts longer than 6 months is unclear. Methods: A retrospective cohort study was conducted …

Summary Background The BNT162b2 mRNA (Pfizer–BioNTech) and ChAdOx1 nCoV-19
(Oxford–AstraZeneca) COVID-19 vaccines have shown high efficacy against disease in …

Objectives To derive and validate risk prediction algorithms (QCOVID4) to estimate the risk
of covid-19 related death and hospital admission in people with a positive SARS-CoV-2 test …