New analysis shows a single shot of the vaccine can reduce the chance of needing hospital treatment by more than 80%.
New Public Health data based on those over 80 who have received the first jab show that the effects kicked in three to four weeks after the first vaccination.
The findings reiterate those found by Scottish health authorities last week which were hailed ‘spectacular’. Scientists have stressed that two doses are needed for best protection.
On Monday, health secretary Matt Hancock told a Downing Street briefing that the latest vaccine results were ‘very strong’.
Hancock added: “They may also help to explain why the number of Covid admissions to intensive care units among people over 80 in the UK have dropped to single figures in the last couple of weeks.”
England’s deputy chief medical officer, Prof Jonathan Van-Tam also added that the data offered a glimpse of how the vaccine programme ‘is going to hopefully take us into a very different world in the next few month’.
He explained that it was ‘absolutely critical’ that second doses ‘are still part of the course of immunisation against Covid-19 and no less important’.
Prof Van-Tam stressed there was a ‘significant likelihood’ that a second dose of a vaccine would ‘mature your immune response, possibly make it broader and almost certainly make it longer than it would otherwise be in relation to a first dose only’.
The PHE data – that has not yet been peer reviewed – suggests that the Pfizer vaccine leads to an 83% reduction in deaths from Covid in those over 80.
It also reduces the risk of people over 70 developing any symptoms by around 60%, three weeks after the first dose.
Prof Van-Tam explained that the decision to give the AstraZeneca vaccine – which was rolled out a month after the Pfizer vaccine – to older people was ‘clearly vindicated’. It comes after some European nations refused to give it to over 65s as trials were mainly done on younger adults.
He added that other countries would be ‘very interested’ in the data coming out of the UK.
Dr Mary Ramsay, Public Health England’s head of immunisation, said: “While there remains much more data to follow, this is encouraging and we are increasingly confident that vaccines are making a real difference.”
More evidence is needed to know how the vaccines protects against the Brazil variant (E484) that has been identified in the UK.
The government plans to offer 32 million people (nearly half the population) the first dose of the vaccine by the middle of April.
Currently, 30.4% of the UK population has received the first dose and 1.2% have received the second dose according to the latest Gov.uk data.