Vaccines, excellent real world data

Pfizer-BioNTech vaccine provides high levels of protection from the first dose

https://www.gov.uk/government/news/first-real-world-uk-data-shows-pfizer-biontech-vaccine-provides-high-levels-of-protection-from-the-first-dose

https://papers.ssrn.com/sol3/papers.cfm?abstract_id=3790399

BNT162b2 mRNA

Vaccine effectiveness in healthcare worker

Prospective cohort study of staff undergoing regular asymptomatic testing.

The SIREN study

N = 29,378

2 weekly intervals

Records symptoms, PCR and antibody test results

Therefore symptomatic and asymptomatic infections

Hazard ratios to compare time

Infection in unvaccinated and vaccinated groups

Findings, 5th February 2021

People who were antibody negative on recruitment

A single dose of BNT162b2 vaccine, effectiveness of 72%

21 days after first dose

Rising to 86% seven days after two doses

Conclusion

Vaccine effectively prevents both symptomatic and asymptomatic infection in working age adults

Cohort was vaccinated when the dominant variant in circulation was B1.1.7

Consistent data

Israel, Norwich Medical School

Pfizer COVID-19 BNT162b2 vaccine, after a single dose, ‘real-world’

At day 21

Vaccine effectiveness, 91%

After day 21

Remained at 90%

Expected to last form 9 weeks to 6 months

Vaccine effectiveness seems to be better at reducing severe disease that at reducing mild disease

Public health Scotland

Fourth week after first dose, reduced risk of hospitalisation

Pfizer, down 84% (n = 650,000)

Oxford-AstraZeneca, down 94% (n = 490,000)

Combined reduction in over 80s

Vaccination associated with 81% reduction in hospitalisation risk in the fourth week