https://www.gov.uk/government/news/new-data-show-vaccines-reduce-severe-covid-19-in-older-adults
Early effectiveness of COVID-19 vaccination with BNT162b2 mRNA vaccine and ChAdOx1 adenovirus vector vaccine on symptomatic disease, hospitalisations and mortality in older adults in the UK: a test negative case control study
https://khub.net/documents/135939561/430986542/Early+effectiveness+of+COVID+vaccines.pdf/ffd7161c-b255-8e88-c2dc-88979fc2cc1b?t=1614617945615
Objectives
Real-world effectiveness of the Pfizer/BioNTech BNT162b2 vaccine and …
Astrazeneca ChAdOx1 vaccine against….
Confirmed COVID-19, hospitalisations and deaths
To estimate effectiveness on the UK variant of concern.
Setting
Community COVID-19 PCR testing in England
8th December 2020 and 19th February 2021
All adults in England aged 70 years and older (over 7.5 million)
All symptomatic COVID-19 testing in the community in over 70s
Test negative case control design
174,731 PCR tests
156,930 of these (89.8%) linked to vaccination data
44,590 (28.4%) were positive tests
112,340 (71.6%) were negative
Interventions
One and two doses of BNT162b2 vaccine
One dose of ChAdOx1 vaccine
Main outcome measures
Symptomatic PCR confirmed SARS-CoV-2 infection
Hospitalisations and deaths with COVID-19.
Symptomatic disease infection risk Results
Individuals aged more than 80 years vaccinated with Pfizer BNT162b2
Higher odds of testing positive in the first 9 days after vaccination (odds ratio up to 1.48)
Vaccine effects were noted from 10-13 days after vaccination
Reaching an effectiveness of 70% from 28-34 days, then plateauing
From 14 days after the second dose, vaccine effectiveness was 89%
(Fewer than 10 over 80 sent to ITU every day in UK)
Individuals aged more than70 years
Pfizer BNT162b2
Vaccine effectiveness reached 61% from 28-34 days then plateaued
AZ ChAdOx1
Vaccine effects, were seen from 14-20 days
Reaching an effectiveness of 60% from 28-34 days
Further increa..
