Has a new mutation of COVID-19 just mooted the multi-billion-dollar effort to find vaccines? “Very unlikely,” Operation Warp Speed’s top scientist told CNN’s Jake Tapper yesterday. While nations shut down travel to the UK to keep the new and much more contagious variant from spreading past its borders, Dr. Moncef Slaoui told the State of the Union audience that the vaccines now approved would almost certainly defeat it anyway.

It’s not impossible that it could get around the vaccine, but the targeting of the spike protein is so efficient that it’s all but impossible, Slaoui said:

TAPPER: Absolutely. There’s a light at the end of the tunnel, thanks to the efforts of you and the scientists for Operation Warp Speed. I want to ask you. British Prime Minister Boris Johnson says he’s now imposing stricter guidelines because there’s this new variant of COVID-19 spreading in the U.K. that — quote — “may be up to 70 percent more transmissible than the earlier strain.” Do you think that variant is here in the U.S.? What can you tell us about it?

SLAOUI: So, we don’t know yet. We are, of course, particularly the NIH and the CDC, looking very carefully into this. Many, many strains of the virus are sequenced all the time. This is virus is what is called RNA virus. This is an approach to being a virus that is prone to more mistakes in the way RNA is made than when it’s a DNA virus. And, therefore, there will be variance.

The key is that the spike protein requires really very, very specific three-dimensional structure that makes it hard for it to mutate too much. So, up to now, I don’t think there has been a single variant that would be resistant to the virus — to the vaccine. We can’t exclude it, but it’s not there now. And this particular variant in the U.K., I think, is very unlikely to have escaped the vaccine immunity.

TAPPER: OK, so you are confident that the vaccines we have, Pfizer and Moderna, will also protect against any of these new variants that we’re hearing about, whether in the U.K. or South Africa?

SLAOUI: Well, you can never say never in science, so there could be at some point something that comes up that helps the virus escape. But, because the vaccines are inducing antibodies against many different parts of the spike protein, the chances that all of them change, I think, are low, but they are not inexistent.

Let’s hope Slaoui’s right — and he almost certainly is. We’re used to the flu vaccine, which has limited effect because of the significant mutations that the virus makes each year. Those vaccines rely on whole-virus exposures, in which manufacturers have to guess which strains might be most prevalent ahead of the season. Even a wrong guess can help boost antibodies in general, which is why the vaccine is worthwhile either way. The mechanism behind the Pfizer and Moderna vaccines — messenger RNA sequences or mRNA — is entirely different. It teaches the body how to stop the process by which the virus replicates, which should be relatively stable regardless of variant.

The UK certainly hopes that’s the case. Travel bans will keep British travelers at home altogether, and health officials worry that another countrywide lockdown might be necessary:

The new mutation, or variant, was first detected in southeast England in September and is quickly becoming the dominant strain in London and other regions in Britain. Experts said it does not appear more deadly or resistant to vaccines.

At a news conference from 10 Downing Street, British Prime Minister Boris Johnson said the new variant “may be up to 70 percent more transmissible” than previous versions of the virus here.

“This is spreading very fast,” he said, announcing local and international travel bans and other extreme measures for about 18 million people in England beginning Sunday. Wales and Scotland followed with their own tightened restrictions, including banning all but essential movement around the isle.

Many countries have reimposed tough social distancing measures as coronavirus cases roared back in second and third waves. Britain, however, appears to be the first to point to a specific coronavirus variant for a surge in infections and the need to bring back the toughest measures.

The UK has already begun rolling out the Pfizer vaccinations, and will shortly do the same for Moderna if they haven’t yet already. That will hopefully stanch the transmission spike in the new variant within the next few weeks. If left unchecked, the variant’s rapid transmission could spark more variations and perhaps even some significant mutations, which could threaten to escalate the virus’ resistance to the vaccines.

In other words, we should be very happy that the vaccines have arrived when they did for even more reasons now. This is good news … if we can vaccinate enough people quickly.