One dose of vaccine against Covid-19 in Scotland has cut hospital admissions by more than 85%, according to the first data to be published on the impact of the UK programme.
By the fourth week after receiving the initial dose, the Pfizer and Oxford-AstraZeneca vaccines had reduced the risk of hospitalisation from Covid-19 by up to 85% and 94% respectively, according to a study by Scottish universities and Public Health Scotland.
Among people aged 80 and over – those at highest risk because of their advanced years – vaccination was associated with an 81% reduction in hospital admission risk in the fourth week, when the results for both vaccines were combined.
“The brilliant news is that [the study suggests] the vaccine delivery programme, in its current format … is working,” said Dr Josie Murray, of Public Health Scotland, who was involved in the study, known as the EAVE-II project.
“The other fantastic news is that we are potentially protecting our NHS hospitals, from people needing to attend as a consequence of the Covid-19 if they’ve had the vaccine.”
The study suggested that both vaccines were working well, said the researchers. The study was not set up to look at any differences between the two. The Pfizer/BioNTech was available first so there is more data, but the Oxford/AstraZeneca was mostly used in the older age group.
The Oxford/AstraZeneca vaccine appears to have performed very well in older people. Only two people given that vaccine were admitted to hospital in the study. There were more hospital admissions in those given the Pfizer vaccine, but among more people immunised. Even so, the very good Oxford vaccine results could cause a rethink in those countries that have decided not to allow it to be used in people over the age of 65 because of a shortage of trial data.
Both vaccines are being given as single doses until up to 12 weeks. While there is trial data to support the gap for the AstraZeneca vaccine, there is none for the Pfizer vaccine, which was given as a second dose at three weeks.
The study showed an apparent rise in the number of hospital admissions among people given one dose of the Pfizer vaccine after 21 days. The numbers were very small and there was uncertainty over their significance, said the researchers.
“We haven’t specifically looked at the idea of waning immunity,” said Prof Chris Robertson, from the University of Strathclyde and statistics lead with the health protection group of Public Health Scotland.
He said the numbers were consistent with a relatively constant protection of about 70% at that stage. “It is an important point but we can’t at the moment say anything about that,” he said. They needed further analyses with longer-term follow-up.
Murray said the prioritisation guidance from the Joint Committee on Vaccine and Immunisation (JCVI) on which groups should get the vaccines first was working, and she called for everybody to accept both doses when offered.
“We are asking everybody that if you are offered the vaccine, please take your first dose,” she said. “The first thing we can say based on these data, is that when you are offered the second dose, please also take that because it’s very important. We can see from these data that you can protect yourself and your family and your friends.”
People should continue to follow all the public health guidance, such as washing hands and keeping apart, even when they have been vaccinated, she said.
Data on vaccine effect was gathered between 8 December and 15 February. During this period, 1.14m vaccine doses were administered and 21% of the Scottish population received a first dose. About 650,000 people have had the Pfizer vaccine and 490,000 have had the Oxford-AstraZeneca vaccine.
“These results are very encouraging and have given us great reasons to be optimistic for the future. We now have national evidence – across an entire country – that vaccination provides protection against Covid-19 hospitalisations,” said the lead researcher, Prof Aziz Sheikh, director of the University of Edinburgh’s Usher Institute.
“Rollout of the first vaccine dose now needs to be accelerated globally to help overcome this terrible disease.”