England lifted almost all of its pandemic restrictions on Monday, which some Britons have hailed as ‘freedom day’. However, the British government made a notable exception: people traveling to England from France must remain in quarantine upon arrival, even if they have been fully vaccinated.
The rule, announced Friday, was fueled by concerns about the presence of the beta variant of the coronavirus in France and is intended as a precautionary measure, officials said.
“While vaccines help us turn the tables against this virus, we need to proceed with caution,” said Dr. Jenny Harries, the chief executive of the UK Health Security Agency, said in a statement on Friday. “That means we have to maintain our defenses against new variants and protect our hard-won progress through the exceptional rollout of vaccinations.”
Here are answers to some frequently asked questions about the beta variant.
What is the Beta variant?
The beta variant, previously known as B.1.351, was first discovered in South Africa last year. It contains several mutations, in a protein called spike, that allow the virus to bind more tightly to human cells.
It also contains the E484K mutation, also known as the “Eek” mutation, which appears to help the virus partially evade antibodies. This mutation has emerged independently in multiple variants, including Gamma, which showed up in Brazil, and in some samples of Alpha, which were first identified in Britain.
The World Health Organization and the Centers for Disease Control and Prevention have both identified beta as a “variant of concern.”
Why are people concerned about it?
Scientists and health officials were concerned about beta because it was spreading quickly through South Africa, and research showed that some vaccines were less potent against it.
For example, South Africa stopped using the AstraZeneca-Oxford vaccine in February after clinical trials suggested the vaccine did not provide good protection against mild or moderate disease caused by beta. (Following research, however, has suggested that several licensed vaccines offer strong protection against serious diseases caused by the variant.)
Some monoclonal antibody treatments are also less effective against the variant, although there are other approved antibody treatments that seem to work well against it.
Beta’s ability to bind tightly to human cells may also make it more transferable; the CDC notes that it appears to be about 50 percent more contagious than the original strain of the virus. However, it doesn’t seem as contagious as Delta.
Where is it common?
Beta has now been reported in 123 countries, but it is much less common than Delta.
Initially, beta spread widely throughout South Africa, where it once made up more than 95 percent of virus samples sequenced in the country.
It’s not so dominant anymore. In the past four weeks, beta has accounted for just 5.6 percent of virus samples sequenced in South Africa, according to GISAID, a repository of viral genomes. (This decrease is most likely due to the advent of the highly contagious Delta variant, which now accounts for 77.6 percent of the sequences.)
In the past four weeks, the variant also represented 3.7 percent of virus samples sequenced in France, according to GISAID. It is especially common on Réunion, a French island in the Indian Ocean, where beta makes up 31.2 percent of the sequences.
Beta is not common in the United States, where it accounts for only 0.1 percent of infections, according to CDC estimates. It was discovered in Britain but is responsible for a negligible proportion of infections there.
Do the Beta Vaccines Work?
The vaccines appear to be less potent against beta than against other versions of the virus. But studies suggest that two doses of several commonly used vaccines should still provide strong protection.
Studies in Qatar, where the beta variant was once responsible for half of all infections, have shown that two doses of the Pfizer vaccine are 72 to 75 percent effective at preventing infection with beta, a lower degree of protection than the injections offer against other variants. But both the Pfizer and Moderna vaccines provided strong protection against the worst results; a full course of both vaccines was more than 95 percent effective in preventing serious illness and death.
“While Pfizer’s efficacy was only 75 percent against beta, and thus breakthrough beta infections are not uncommon, these breakthrough infections are mild and it is very rare for someone who has been fully vaccinated to require serious hospitalization or die from a breakthrough beta infection. Laith Abu-Raddad, an infectious disease epidemiologist at Weill Cornell Medicine-Qatar who led both studies, said in an email.
As extra good news, he added that there is also “no sign” that the protection these vaccines provide against beta has declined in the first few months after the injections.
In a clinical trial in South Africa conducted when Beta was dominant, the Johnson & Johnson vaccine had an overall efficacy rate of 64 percent, but 82 percent efficacy in preventing serious disease.