A new study provides support for high effectiveness of the Pfizer COVID vaccine against hospital admissions up until around 6 months after being fully vaccinated. The real-world, retrospective cohort study included data from 3.4 million Californian residents and was recently published in The Lancet. 

The importance of this Californian study is that up until now we've mainly relied on phase three study results to assess vaccine efficacy. This study (and another, even bigger one in Chile—with the CoronaVac) brings much greater statistical significance to the outcome findings and makes it possible to look at subgroups.

In this episode, Lead author Dr. Sara Y Tartof, a Research Scientist Epidemiologist with Kaiser Permanente Department of Research & Evaluation in Southern California discusses the implications for vaccination programs with Oncology Times reporter Peter Goodwin.