Scientists have said the lifting of restrictions on fully vaccinated arrivals to the UK from the EU and the US, which starts from Monday, is not without risk.
From 4 a.m. on Monday, those who have been fully vaccinated in the US and Europe will be treated the same as UK residents, meaning arrivals from Amber List countries will not have to be quarantined when they enter England, nor to be tested on the eighth day after their arrival.
Instead, they will only be required to take a pre-departure test and PCR test no later than the second day after arrival – although different rules will apply for those traveling from France.
While the change is likely to be welcomed by travelers, scientists have issued a note of caution.
Professor Rowland Kao, an epidemiologist at the University of Edinburgh, said the risk lies in simultaneously opening the borders to fully vaccinated people while allowing the virus to spread so that large numbers of the population of the United Kingdom is infected.
This situation, he said, is of concern, as fully vaccinated people “although at relatively low risk for Covid, would by definition have a similar risk of carrying” breakout mutants “that escape vaccines”, adding that with high levels of spread it would be “difficult to eliminate such variants, if they are imported from abroad”.
One complication is that with high levels of infection, there has been a drop in the proportion of positive samples analyzed by genome sequencing, or the faster approach known as genotyping, to determine the variant qu ‘they contain.
“Since this is the primary way we identify the variants, it would mean that it will be very difficult to stop or even slow down the spread of all the variants in the country,” said Kao, who is a participant of Spi-M (the Pandemic Influenza Modeling Group).
“Of course, if the currently encouraging signs of declining cases continue, we should soon be in a position where the greatest risk has passed – however, some delay in lifting the restrictions would be epidemiologically reasonable. “
Professor Julian Hiscox, Chair of Infection and Global Health at the University of Liverpool, who participates in the Advisory Group on New and Emerging Respiratory Virus Threats (Nervtag), which advises the government on the dangers posed by new respiratory viruses, also urged caution. .
“As with anything related to Covid, there is a balance between infection and the consequences for human health and other factors such as the economy and people having fun,” he said. declared.
“Although the case rates and the corresponding likelihood of new variants are high, caution would dictate a more cautious approach. “
But Professor Adam Finn of the University of Bristol, who is a member of the Joint Committee on Vaccination and Immunization, said the rule change could have benefits.
“We know that people who are completely immune can be infected. They are much less likely to get seriously ill than unimmunized people when infected, including with delta and other variants, and a little less likely to be infected at all, ”he said. .
“Evidence is only emerging now as to whether, when infected, they are less likely to infect others, but it probably will at least to some extent.
“Granting increased freedoms to vaccinated people combined with continuous testing before and after travel therefore makes some logical sense, but of course carries a continued risk of virus importation.
“As in other areas of politics, this is a balancing act trying to find the best compromise between too much risk and too much caution. If this encourages more people to get the full vaccine, that is of course a bonus for them and for everyone. “
Professor Peter Openshaw of Imperial College London, who is another Nervtag participant, also said the rule change made immunological sense.
“In terms of harmonizing the recognition of vaccines delivered elsewhere, this also seems perfectly reasonable, as long as it is countries that have proper tracking and registration of vaccines delivered,” he said.
But, Openshaw added, it is very difficult for politicians when they rely on preliminary information, for example around transmission. “A lot of this is based on pretty weak evidence,” he said.
Dr Michael Head, a senior researcher in global health at the University of Southampton, said there may be some common ground when it comes to the rule change.
“For recent international arrivals who received two doses, replacing quarantine with daily testing would be a reasonable pragmatic compromise,” he said.