Ending Covid lockdown restrictions too swiftly could run the risk of new vaccine-resistant variants taking hold, top expert Sarah Gilbert has said.
Speaking to MPs on Wednesday, Oxford University’s professor of vaccinology also warned relaxing restrictions too quickly could boost transmission of the virus.
It comes after Boris Johnson this week revealed his roadmap out of lockdown, with a pledge to end all social distancing by June 21.
Gilbert has urged caution, however, telling the Commons’ science and technology committee: “To make sure that we have the lowest chance possible of new variants arising we need to prevent the virus from transmitting between people and we’re now doing that very effectively with the vaccines.”
She added: “We cannot allow only the vaccines to do all the work of protecting the population, while at the current time in the UK we still have relatively high levels of transmission.
“And there is a danger that if measures are lifted too quickly that transmission could increase, and that puts us at a greater risk of selection of new variants that are not so well effectively neutralised by the virus.
“It wouldn’t be all or nothing but it could be a significant change, and we want to minimise the chances of that happening as much as we possibly can.”
Anthony Harnden, deputy chair of the Joint Committee on Vaccination and Immunisation (JCVI) agreed “it’s really, really important that we don’t rush this”.
He said: “I refer back to my original answer about vaccination not being the only way out pandemic.
“We must go slowly, and the reason is because we want to keep transmission down and we want to keep infection rates down. And if we don’t, we will lose all the benefits of those vaccines that we’ve acquired and in the last few months because we will get the environment for new variant strains to emerge and have ‘vaccine escape’. So it’s really, really important that we don’t rush this.”
Schools are scheduled to reopen on March 8, followed by relaxations of some social distancing measures later in the month.
Non-essential shops, pubs, restaurants, hairdressers and gyms will reopen no earlier than April 12 in the prime minister’s phased plan.
Johnson is under pressure from backbench Tory MPs in the Covid Recovery Group, who have been demanding the government speeds up the plan.
The PM has argued, however, that England is taking a “cautious but irreversible” path out of lockdown.
Scientists are still examining new data about how effective the vaccines are in reducing transmission and hospitalisations.
Philip Dormitzer, vice president and chief scientific officer of viral vaccines at Pfizer, said the company believes its vaccine will protect against the variants seen to date.
He told the committee: “From real world effectiveness data, both UK and in Israel where the UK variant is common, we’re starting to get our first direct evidence, and we are seeing protection against the UK variant that is equivalent to the protection we saw in controlled trials before that variant was circulating.
“For other variants at this point we have to rely more on laboratory data, and the laboratory data thus far, I would say are quite reassuring.
“We do see with the South African variant some reduction in the level of neutralisation.
“So yes these mutations can reduce the level of neutralisation, but they do not reduce the level of neutralisation anywhere near as low as neutralisation that was observed at the time that people were protected in the trial.
“So we think it is likely that the vaccine will protect against the variants that we have seen to date, but the way to be sure is of course the real world data because laboratory measures of immunity cannot be translated directly to known protection – that requires actually observing protection in the field.”