The dynamic and rapidly changing pattern of virus exposure and level of population
immunity during the evolving pandemic are potentially important confounders in the …

The efficacy of SARS-CoV-2 vaccines reported in Phase 3 trials varies from~ 45% to~ 95%.
This study tests the hypothesis that the observed variation in efficacy of SARS-CoV-2 …

Vaccines against COVID-19 approved for use in the EU/EEA have been shown to be highly
effective against wild-type SARS-CoV-2. However, their effectiveness against new variants …

Abstract Coronavirus disease 2019 (COVID-19) vaccine trials provide valuable insight into
the safety and efficacy of vaccines, with individually randomized, placebo-controlled trials …

Observational studies of the effectiveness of vaccines to prevent COVID-19 are needed to
inform real-world use. Such studies are now underway amid the ongoing rollout of SARS …

In all pivotal trials of COVID-19 vaccines, the history of previous SARS-CoV-2 infection was
mentioned as one of the main exclusion criteria. In the absence of clinical trials …

Background: The multiple efficacious vaccines authorised for emergency use worldwide
represent the first preventative intervention against coronavirus disease 2019 (COVID-19) …

Developing a safe and effective vaccine against severe acute respiratory syndrome
coronavirus 2 (SARS-CoV-2) is crucial to ending the COVID-19 pandemic. But even during a …

Background: Although several COVID-19 vaccines have been found to be effective in
rigorous evaluation and have emerging availability in parts of the world, their supply will be …

The urgency to develop vaccines during the COVID-19 pandemic has resulted in the
acceleration of clinical trials. Specifically, a broad spectrum of efficacy levels has been …