Both UK vaccines working

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

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 increasing to 73% from day 35 onwards

Risk of emergency hospitalisation and death results

One dose of BNT162b2

Additional 43% lower risk of emergency hospitalisation

Additional 51% lower risk of death

One dose of ChAdOx1

Additional 37% lower risk of emergency hospitalisation

Insufficient follow-up to assess the effect of ChAdOx1 on mortality

Combined with the effect against symptomatic disease

Single dose of either vaccine is approximately 80% effective at preventing hospitalisation

Single dose of BNT162b2 is 85% effective at preventing death

Single dose of ChAdOx1 unknown protective effect against death

Conclusion

Significant reduction in symptomatic SARS-CoV2 positive cases in older adults

Even greater protection against severe disease

Both vaccines show similar effects

Protection was maintained for more than 6 weeks

A second dose of BNT162b2 provides further protection against symptomatic disease

Second doses of ChAdOx1 have not yet been rolled out in England

There is a clear effect of the vaccines against the UK variant of concern

Professor Jonathan Van-Tam

Joint Committee on Vaccination and Immunisation

not immunologically plausible the vaccine would work in younger age groups and not older ones.

Dr Mary Ramsay, PHE's head of immunisation, said it could.

If anything we would expect it to be a stronger protection from the vaccine

Lower down in the age range is that people's chances of being hospitalised and dying are much lower

France

Oxford/AstraZeneca vaccine, can be given to people with underlying health conditions in the 65-74 age group

1.1m doses in country

Germany

Still not giving the AstraZeneca to the over-65s

Now under discussion

Large stocks of that vaccine waiting to be used

(Belgium, Poland, Italy, Sweden)

Professor Andrew Pollard, Oxford Vaccine group

Findings were stunning

5,000 people dying every day in Europe, important to increase confidence in vaccines

disappointing in some senses

really high levels of protection

support their decision making

Oxford vaccine distributed to low-income countries, Covax scheme