1.8 ml sodium chloride is added to a vial of Pfizer / BioNTech COVID-19 vaccine concentrate ready for administration at Guy’s Hospital at the start of the largest vaccination program in UK history on December 8, 2020 in London, UK.

Victoria Jones – Pool | Getty Images

LONDON – New data from England has shown how effective coronavirus vaccines are in fighting the disease, even after just one dose.

In December, the vaccine developed by Pfizer and BioNTech became the first vaccine to be approved and launched in the UK

The elderly, health workers and nursing home workers were the first to be vaccinated. This was soon followed by the shot developed by the British company AstraZeneca and the University of Oxford, another vaccine that requires two doses.

Infection control

Figures in a research report by Public Health England released Monday, but pending peer review, showed Pfizer and Oxford-AstraZeneca vaccines are highly effective in reducing Covid infections in people aged 70 and over.

Since the study began in January, protection against symptomatic Covid four weeks after the first dose has ranged between 57% and 61% for the Pfizer vaccine and between 60% and 73% for the AstraZeneca vaccine.

The effectiveness of the vaccine in the data for Public Health England is calculated using a mathematical statistic called the odds ratio. Click here for full data and methods.

Reduce hospital stays and deaths

The study, which included data from over 7.5 million people, also found that a single dose offered additional protection against hospitalizations and death.

It is said that coronavirus cases in vaccinated people had about half the risk of severe outcomes compared to non-vaccinated cases. It combined this with estimates of their effectiveness against symptomatic disease and predicted that a single dose of either vaccine would be about 80% effective in preventing hospitalization in the elderly about three to four weeks after the first dose.

It has also been suggested that a single dose of the Pfizer vaccine is 85% effective in preventing death from Covid-19 in those over 80.

British Health Secretary Matt Hancock called the results “very strong”.

“They could also help explain why the number of Covid ICU admissions for people over 80 in the UK has dropped to single digits in recent weeks,” he said.

UK policymakers feel vindicated after deciding to postpone the second dose to around three months in order to vaccinate more people with a first dose faster. Experts in the US hesitated with the strategy, and White House chief medical officer Dr. Anthony Fauci said Monday that “there are risks on both sides”.

As of Sunday, 20,275,451 Brits have received their first dose of vaccine and 815,816 have received both doses, government data said.

The UK vaccination program was widely hailed as a triumph amid tragedy. The UK has the fifth highest number of infections in the world after the US, India, Brazil and Russia, with nearly 4.2 million infections and over 123,000 deaths. This is the fifth highest number of deaths in the world, according to Johns Hopkins University.

—CNBC’s Bryn Bache contributed to this article.