Tuesday, March 02, 2021

PHE Preprint: Pfizer-BioNTech and Oxford-AstraZeneca Vaccines Reduce Severe COVID-19 in Older Adults



While there are certainly unknowns regarding how well current vaccines will fare against some of the emerging COVID variants, and a strong possibility that booster shots will be needed down the line, I count myself as someone who is eagerly looking forward to the day I can get my first dose of (any) of the three COVID vaccines available in the United States. 

Not that I expect it to be a 100% shield against infection (it isn't), or even a guarantee against severe illness from SARS-CoV-2 infection.  But increasingly, data from places where significant quantities of vaccine have been rolled out have shown a beneficial effect. 

The CDC's MMWR published a report last week showing a significant reduction in patients requiring mechanical ventilation in Israel following their massive vaccination program. 
Reduction in COVID-19 Patients Requiring Mechanical Ventilation Following Implementation of a National COVID-19 Vaccination Program — Israel, December 2020–February 2021

Early Release / February 26, 2021 / 70

Ehud Rinott1,*; Ilan Youngster, MD2,*; Yair E. Lewis, MD, PhD3 


What is already known about this topic?

Clinical trials have demonstrated the efficacy of COVID-19 vaccines in a controlled setting. Israel initiated a national vaccination campaign in December 2020, prioritizing persons aged >60 years and other high-risk populations.

What is added by this report?

By February 2021, 2-dose vaccination coverage was 84% among persons aged ≥70 years and 10% among those aged <50 years. The ratio of COVID-19 patients aged ≥70 years requiring mechanical ventilation to those aged <50 years declined 67% from October–December 2020 to February 2021.

What are the implications for public health practice?

These findings provide preliminary evidence of the effectiveness of vaccines in preventing severe cases of COVID-19 at the national level in Israel.

In a similar vein, we have an encouraging report from the UK's PHE on a preprint showing a significant reduction in severe illness in older recipients of two different COVID vaccines. While preliminary data, it suggests an 80% decrease in hospitalizations among recipients over the age of 80, and a 70% reduction in symptomatic infections in those over 70.

First, the PHE press release, followed by a link to the 21-page PDF study.  And for a last stop, expert reaction from the Science Media Centre. 

New data show vaccines reduce severe COVID-19 in older adults

New data show both Pfizer-BioNTech and Oxford-AstraZeneca vaccines significantly reduce severe COVID-19 in older adults.
Published:1 March 2021

Today Public Health England (PHE) has submitted a pre-print of a real-world study that shows that both the Pfizer and Oxford-AstraZeneca vaccines are highly effective in reducing COVID-19 infections among older people aged 70 years and over. Since January, protection against symptomatic COVID, 4 weeks after the first dose, ranged between 57 and 61% for one dose of Pfizer and between 60 and 73% for the Oxford-AstraZeneca vaccine.

The pre-print article:
  • compares the rate of vaccination in symptomatic people aged over 70 years of age who test positive for COVID-19, compared to those who test negative
  • compares the rate of hospitalisation in confirmed COVID-19 cases aged over 80 who were vaccinated more than 14 days before testing positive, compared to unvaccinated cases
  • compares the rate of deaths in confirmed COVID-19 cases aged over 80 who were vaccinated with Pfizer vaccine more than 14 days before testing positive, compared to unvaccinated cases
In the over 80s, data suggest that a single dose of either vaccine is more than 80% effective at preventing hospitalisation, around 3 to 4 weeks after the jab. There is also evidence for the Pfizer vaccine, which suggests it leads to an 83% reduction in deaths from COVID-19.

The data also shows symptomatic infections in over 70s decreasing from around 3 weeks after one dose of both vaccines.

The new analysis adds to growing evidence that the vaccines are working and are highly effective in protecting people against severe illness, hospitalisation and death.

Dr Mary Ramsay, PHE Head of Immunisation, said:
“This adds to growing evidence showing that the vaccines are working to reduce infections and save lives.
“While there remains much more data to follow, this is encouraging and we are increasingly confident that vaccines are making a real difference.
“It is important to remember that protection is not complete and we don’t yet know how much these vaccines will reduce the risk of you passing COVID-19 onto others.
“Even if you have been vaccinated, it is it is really important that you continue to act like you have the virus, practise good hand hygiene and stay at home.
From this week, the NHS has started to deliver second doses to those people vaccinated first, which will provide higher and longer lasting protection.

Separate studies in healthcare workers show that one dose of the vaccine is preventing people from catching asymptomatic COVID-19 by at least 70%. This will help to reduce the spread of infection in hospitals and care homes, ultimately offering more protection to these vulnerable populations.

The full study is available at the link below:

Early effectiveness of COVID-19 vaccination with BNT162b2 mRNAvaccine and ChAdOx1 adenovirus vector vaccine on symptomaticdisease, hospitalisations and mortality in older adults in the UK: a testnegative case control study 

Jamie Lopez Bernal1,2,3, Nick Andrews1,2, Charlotte Gower1 , Chris Robertson4 , Julia Stowe1 , Elise Tessier1 , Ruth Simmons,1 Simon Cottrell5 , Richard Roberts5 , Mark O’Doherty6 , Kevin Brown1 , Claire Cameron7 , Diane Stockton7 , Jim McMenamin7 , Mary Ramsay1,2 
1. Public Health England, London, United Kingdom
2. NIHR Health Protection Research Unit in Vaccines and Immunisation, London School of Hygiene and Tropical Medicine, London, United Kingdom
3. NIHR Health Protection Research Unit in Respiratory Infections, Imperial College London, United Kingdom
4. University of Strathclyde, Glasgow, United Kingdom.
5. Public Health Wales, Cardiff, United Kingdom.
6. Public Health Agency Northern Ireland, Belfast, United Kingdom.
7. Health Protection Scotland, Glasgow, United Kingdom.

And Expert reactions can be viewed at:

MARCH 1, 2021
Expert reaction to a preprint looking at the early effectiveness of COVID-19 vaccination with the Oxford-AstraZeneca or Pfizer-BioNTech vaccine on symptomatic disease, hospitalisations and mortality in older adults in the UK

A preprint, an unpublished non-peer reviewed study, suggests both the Pfizer-BioNTech and Oxford-AstraZeneca vaccines reduce severe COVID-19 in older adults.

While the current crop of vaccines may not be enough to quickly end the pandemic, they can help blunt its impact, and that can make a huge difference - not only for individuals - but for society as a whole.  

And right now, we need every advantage we can get.