Observational Studies: Apply It 1

  • Recognize observational studies and list the key components
  • Describe confounding factors that may influence an association

Effective Vaccines?

A scientist in a lab coat holds a micropipette facing a bench filled with lab equipment.
Figure 1. Careful data collection and weekly testing helped researchers evaluate how effective the COVID-19 vaccines were after their rollout.

In March 2020, COVID-19 was declared a pandemic by the World Health Organization. In December 2020, vaccines using Messenger RNA technology were given emergency use authorization by the Food and Drug Administration in the United States. Over the next 13 weeks, 3,950 health care personnel, first responders, and other essential and frontline workers who had received the vaccine completed weekly COVID-19 testing to determine whether they had tested positive for COVID-19. In this study, researchers were following the effectiveness of the vaccines in a real-world setting.[1]

  1. Centers for Disease Control and Prevention. (2021, April 2). Interim estimates of vaccine effectiveness of BNT162b2 and mRNA-1273 COVID-19 vaccines in preventing SARS-CoV-2 infection among health care personnel, first responders, and other essential and frontline workers – eight U.S. locations, December 2020-March 2021. Morbidity and Mortality Weekly Report, 70(13), 495-500. https://www.cdc.gov/mmwr/volumes/70/wr/mm7013e3.htm ↵