MEET THE TEAM 

MEET THE TEAM 

     

     

Effectiveness of the Pfizer-BioNTech and Oxford-AstraZeneca vaccines on covid-19 related symptoms, hospital admissions, and mortality in older adults in England: a test-negative case-control study

Home / Resources / Effectiveness of the Pfizer-BioNTech and Oxford-AstraZeneca vaccines on covid-19 related symptoms, hospital admissions, and mortality in older adults in England: a test-negative case-control study
June 1, 2021 by Immunise - a PI India Initiative Resources

To estimate the effectiveness of the Pfizer-BioNTech BNT162b2 and Oxford-AstraZeneca ChAdOx1-S vaccines against confirmed covid-19 symptoms (including the UK variant of concern B.1.1.7), admissions to hospital, and deaths.

  • URL
 https://www.bmj.com/content/373/bmj.n1088.full
  • Date of publication
 13 May 2021, BMJ
  • Category 
 Vaccine Effectiveness 
  • Study Design
 Test negative case-control study
  • Country of Study
 England
  • Level of Evidence
 Level IV: case-control study
  • Aim/ Question studied
 To estimate the effectiveness of the Pfizer-BioNTech BNT162b2 and Oxford-AstraZeneca ChAdOx1-S vaccines against confirmed covid-19 symptoms (including the UK variant of concern B.1.1.7), admissions to hospital, and deaths.
  • Study done / What did they do?
 In the test-negative case control study, they included 156 930 adults aged 70 years and older who reported symptoms of covid-19.

This study provides preliminary real-world evidence for the efficacy of the Pfizer-BioNTech BNT162b2 and Oxford-Asta-Zeneca ChAdOx1-S vaccines against symptomatic covid-19, hospitalizations, and death in older people in England.
Results
  • Participants aged 80 years and older who received BNT162b2 vaccination before January 4, 2021 had a higher risk of testing positive for covid-19 in the first nine days after vaccination. 
  • Vaccine effects were observed 10 to 13 days after vaccination, yielding a vaccine effectiveness of 70%.
  • Vaccination effectiveness of 89 % 14 days after the second dose.
  • The vaccine’s effectiveness with BNT162b2 was 61%.
  • With ChAdOx1-S, effects were seen 14 to 20 days after vaccination, with an effectiveness of 60% from 28 to 34 days, increasing to 73%  from day 35 onwards.
  • Conclusion
 -Vaccination with either BNT162b2 or ChAdOx1-S resulted in a significant reduction in symptomatic covid-19 in older adults, as well as additional protection against severe disease.
  • Summary
 -A single dose of either BNT162b2 or ChAdOx1-S provides significant protection against covid-19 as well as additional protection against severe disease for at least six weeks, including protection against the UK variant of concern (B.1.1.7)

 

– A single dose of either vaccine provides 60-70% protection against symptomatic covid-19 and approximately 80 % protection against hospitalisation.

In adults aged 70 and up, BNT162b2 and ChAdOx1-S provide comparable levels of protection.

 

Leave a Reply

Your email address will not be published.