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COVID-19 vaccines

Efficacy of Pfizer-BioNTech and AstraZeneca Vaccines Against COVID-19 Mortality Among Older Adults

Strategic Insights

— 1 min read

The study published in a pre-print version on medRxiv* provides evidence on the effectiveness of the Pfizer-BioNTech and AstraZeneca vaccines at preventing mortality among older individuals with coronavirus disease 2019 (COVID-19). The analysis of over 48,000 individuals aged 70 years and older found that vaccinated individuals had a reduced risk of death compared to unvaccinated individuals. Among those who received one dose of the Pfizer-BioNTech vaccine, the risk of death was reduced by 44%, while those who received one dose of the AstraZeneca vaccine saw a 55% reduction. The study also found that the second dose of the Pfizer-BioNTech vaccine offered additional protection, highlighting the importance of completing the full two-dose regimen.

Key Takeaways:

  • The Pfizer-BioNTech vaccine reduced the risk of death by 44% among individuals who received one dose, and by 69% among those who received two doses.
  • The AstraZeneca vaccine reduced the risk of death by 55% among individuals who received one dose.
  • The study found that the second dose of the Pfizer-BioNTech vaccine offered additional protection, emphasizing the importance of completing the full two-dose regimen.
  • The analysis included over 48,000 individuals aged 70 years and older, with COVID-19.
  • The study provides evidence that both the Pfizer-BioNTech and AstraZeneca vaccines offer high levels of protection against COVID-19 mortality after a single dose.
  • The findings support prioritizing the first dose in at-risk groups in the context of high disease incidence and vaccine supply or delivery constraints.

Statistics:

  • 48,096 individuals aged 70 years and older were included in the analysis.
  • 79.1% of COVID-19 cases were unvaccinated, while 12.7% had been vaccinated with BNT162b2, and 8.2% had been vaccinated with ChAdOx1.
  • Among individuals aged 80 years and older, 16.1% of unvaccinated individuals died, compared with 9.2% among those vaccinated with one dose of BNT162b2, 11.3% of those vaccinated with one dose of ChAdOx1, and 4.7% of those vaccinated with two doses of BNT162b2.
  • The survival analysis estimated that individuals vaccinated with one dose of BNT162b2 were 44% less likely to die from COVID-19 than unvaccinated individuals, while those vaccinated with one dose of ChAdOx1 were 55% less likely to die and those vaccinated with two doses of BNT162b2 were 69% less likely to die.

Sources:

  • Lopez, et al. (2021). Efficacy of the Pfizer-BioNTech and AstraZeneca vaccines against COVID-19 mortality among older adults. medRxiv* [pre-print version].

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