Scientists are urging people not to “rely on the fact that your neighbours have been vaccinated” as they warned it is “pretty much impossible” for the UK to reach herd immunity against Covid-19.
Professor Paul Hunter and his colleague Alastair Grant, from the University of East Anglia, have warned that herd immunity cannot be achieved either through natural infection or the programme using the Pfizer/BioNTech and Astra Zeneca vaccines.
Prof Hunter told Radio 4’s Today programme that vaccines would allow a return to near-normal life for large parts of society but those who refuse a jab will not be protected by herd immunity.
He said: “The rolling out the vaccine is going to make a huge difference and going to enable us to relax many of the restrictions that we’re under at the moment and, certainly as we’re moving into spring when the better weather comes along, that’ll considerably help.
“I think there are two key issues. The first is that if you are uncertain about whether you want the vaccine or not – and especially if you’re a vulnerable person – you cannot rely on the fact that your neighbours have been vaccinated so please, please, please make sure you go and be vaccinated yourself.”
He said the second issue was that, particularly going into next winter, those who have not had a vaccine were at ongoing risk from coronavirus.
He said there was a need to “make sure we have appropriate tracking and tracing systems in place so that we identify where local outbreaks are occurring early enough to stop them.
“This is something that happens in measles…particular communities with low uptake of measles vaccines can have suddenly very nasty, very severe outbreaks of measles and what you have to do is make sure we’ve got systems in place to spot these early before they become real problems for the people concerned.”
Prof Hunter said it was going to be “pretty much impossible” to reach herd immunity with the vaccines or through naturally-acquired infection.
While vaccines were “very good at stopping people getting severe illness and dying” and will suppress spread of infection to other people, they will not completely stop it.
“There will continue to be a risk to those people who are not vaccinated,” he said.
Meanwhile, Professor Sir Mark Walport, who is advising ministers as a member of the Scientific Advisory Group for Emergencies (Sage), told the Today programme that “all the evidence says have a vaccine”.
He said it was “likely” that restrictions could be eased in the spring as the top nine priority groups are vaccinated.
“The restrictions won’t suddenly all go overnight, we will need to reduce them gradually,” he said, adding it was “difficult to predict the future precisely”.
Asked whether there should be a plan to vaccinate the entire population in the future, including children, he said children do not get severe disease from Covid-19 but can transmit infection so “ultimately yes” they should be vaccinated.
But he said the current plan must be to vaccinate the most at risk.
The UEA study suggests that everyone, including children, would need to be inoculated with the “more effective” Pfizer jab in order for the UK to achieve herd immunity.
Coronavirus vaccines have not been licensed for use in children, but trials with young people are continuing.
The scientists recommend that all health and social care professionals should be vaccinated with either the Pfizer or Moderna jabs, both of which have reported around 95% efficacy in clinical trials, in order to prevent patients and vulnerable people from becoming infected.
The researchers used mathematical modelling to assess how effective the Oxford and Pfizer vaccines would be in bringing the coronavirus reproduction number (R) down.
R is the number of people that one infected person, on average, will pass a virus on to.
Initial findings showed that 69% of the population would need to be given the Pfizer jab, or 93% the Oxford vaccine, to bring the R number below 1.
But when the researchers took into account the highly transmissible UK variant, they found that vaccinating the entire UK population with the Oxford jab would only reduce the R value to 1.3.
Prof Grant said the combination of “relatively low headline efficacy and limited effect on asymptomatic infections” means the Oxford vaccine “cannot take us to herd immunity, even if the whole population is immunised”.
He said: “For this reason, we recommend that health and social care workers, and others who have lots of contacts with those vulnerable to infection, should receive one of the mRNA vaccines in preference.
“The Oxford vaccine will no doubt be an important control intervention, but unless changes to the dose regime can increase its efficacy, it is unlikely to fully control the virus or take the UK population to herd immunity.”