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

• URL

• Date of publication

• Category 

• Study Design

• Country of Study

• Level of Evidence

• Aim/ Question studied

• Study done / What did they do?

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.

• 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

• Summary

– 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.