Half the population will need to be vaccinated to slow the spread of the coronavirus, England’s immunisation chief has said.
Dr Mary Ramsey, head of immunisation at Public Health England, said the COVID-19 vaccine will be given first to the most at-risk people, to prevent them from getting seriously ill and dying, then to a wider group of people, to slow community transmission.
It has been a breakthrough week in the search for vaccines to bring the virus under control, leading many experts to believe a return to normal life could be possible within a year.
Last week, a vaccine being developed by US pharmaceutical giant Pfizer and its German partner BioNTech was found to be 90% effective in preventing COVID-19 in a trial of over 43,000 participants in six countries. No safety concerns or serious side-effects were reported.
Then, on Monday, US firm Moderna showed its vaccine was 95% effective in trials.
Interim data suggests the Moderna vaccine is highly effective in preventing people getting ill and also works across all age groups, including the elderly.
Unlike the Pfizer vaccine, which needs to be stored at -70C, presenting challenges to the task of distribution, the Moderna vaccine remains stable at -20C, equal to most household or medical freezers, for up to six months.
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Dr Ramsay, who has been responsible for the national surveillance of vaccine-preventable diseases at Public Health England since 1994, said vaccination will initially be targeted at the most vulnerable.
Speaking on BBC Breakfast, Dr Ramsay said: “There is two ways that you could use the vaccine, and the one we’re going for is to actually try and prevent people having serious disease and dying of this terrible infection.
“We’re going to target people who are at highest risk, so we should very quickly see an impact in the numbers of deaths that are happening – it will depend a bit on what the background rate is at that time.
“But if we’re in a high-incidence period, and we vaccinate the people at highest risk, we will begin to see an impact on deaths and hospitalisations quite quickly, because we’re going to go for those people who are most likely to end up... in those situations.
“Later on, if it turns out that the vaccine interrupts transmission, then we may give it to a wider group of people. And then we really need to get maybe half the population vaccinated to really see an impact on spread within communities.”
She said the Pfizer vaccine may have to be stored in wholesalers’ warehouses because of the need to keep it below -80C.
While some parts of the UK have facilities that will be able to store the Pfizer vaccine, other parts would have to use commercial freezers.
Though an end to the pandemic may still be a long way off, the breakthroughs mean an end to a life of lockdowns and tier-system restrictions could be in sight.
One of the scientists behind the Pfizer vaccine has said the impact of the jab will kick in next summer, and life should be “back to normal by next winter”.
On Sunday, Professor Ugur Sahin, co-founder of BioNTech, told the BBC’s Andrew Marr Show it was “absolutely essential” to have a high vaccination rate before autumn next year to ensure a return to normal life next winter.
He acknowledged that the next few months will be “hard” and said the promising preliminary results from the vaccine will not have an impact on infection numbers in the current wave.
“Our goal is to deliver more than 300 million of vaccine doses until April next year, which could allow us to already start to make an impact,” he said.
“The bigger impact will happen until summer, the summer will help us anyway because the infection rate will go down in summer.”
Sir John Bell, regius professor of medicine at Oxford University and a member of the UK government’s vaccine taskforce, predicted last week after the Pfizer results were released that life would be back to “normal by spring”.
He also said Oxford University and AstraZeneca’s rival vaccine candidate is likely to be available in “weeks, not months”, and that he’s optimistic it will get a good result as well.
The UK has said not everyone will get a vaccine at once, with priority going to NHS workers and elderly people.
Boris Johnson has warned that it is still "very, very early days" in the development of a vaccine.
Speaking in the Commons on Tuesday, health secretary Matt Hancock said: "We do not yet know whether or when a vaccine is approved, but I have tasked the NHS with being ready from any date from 1 December."
On Sunday, the government said a further 168 people had died within 28 days of testing positive for COVID-19.
There were also a further 24,962 lab-confirmed cases of coronavirus in the UK.
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