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COVID-19

COVID-19 Vaccine Effectiveness Against SARS-CoV-2 Infection

Strategic Insights

— 1 min read

A new study published in The Journal of Infectious Diseases has provided fresh insights into the effectiveness of the Pfizer-BioNTech COVID-19 vaccine against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection among long-term care facility staff in New York City. The research, conducted by the Epidemic Intelligence Service, found that two doses of the vaccine reduced the risk of SARS-CoV-2 infection by approximately 80% in both previously infected and uninfected individuals. The findings support recommendations that all eligible persons, regardless of prior infection, be vaccinated against COVID-19.

Key Takeaways:

  • Two doses of the Pfizer-BioNTech COVID-19 vaccine reduced the risk of SARS-CoV-2 infection by approximately 80% in both previously infected and uninfected individuals.
  • The vaccine was 54.6% (95% confidence interval, 38.0%-66.8%) more effective among unvaccinated, previously infected persons.
  • Fully vaccinated persons without prior infection had an 80.0% (67.6%-87.7%) lower risk of SARS-CoV-2 infection.
  • Persons fully vaccinated after prior infection had an 82.4% (70.8%-89.3%) lower risk of SARS-CoV-2 infection.
  • The study included long-term care facility staff in New York City aged 18 and above.
  • The research concluded that two doses of the Pfizer-BioNTech COVID-19 vaccine reduced severe acute respiratory syndrome coronavirus 2 infection risk by approximately 80% and increased protection from prior infection alone.

Statistics:

  • 54.6% lower risk of SARS-CoV-2 infection among unvaccinated, previously infected persons.
  • 80.0% (67.6%-87.7%) lower risk of SARS-CoV-2 infection in fully vaccinated persons without prior infection.
  • 82.4% (70.8%-89.3%) lower risk of SARS-CoV-2 infection in persons fully vaccinated after prior infection.
  • 80% reduction in SARS-CoV-2 infection risk with two doses of Pfizer-BioNTech COVID-19 vaccine.
  • 18 and above years old: long-term care facility staff in New York City included in the study.
  • January-June 2021: timeframe for the study.

Sources:

  • The Journal of Infectious Diseases, "Pfizer-biontech Coronavirus Disease 2019 Vaccine Effectiveness Against Severe Acute Respiratory Syndrome Coronavirus 2 Infection Among Long-term Care Facility Staff With and Without Prior Infection In New York City, January-june 2021", 2023;227(4):533-542.
  • NewsRx, "Data on COVID-19 Discussed by Researchers at Epidemic Intelligence Service (Pfizer-biontech Coronavirus Disease 2019 Vaccine Effectiveness Against Severe Acute Respiratory Syndrome Coronavirus 2 Infection Among Long-term Care Facility Staff ...)", March 6, 2023; p 139.

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