Sam Fazeli, a Bloomberg Opinion contributor who covers the pharmaceutical industry for Bloomberg Intelligence, answered questions about the emergence in the U.K. of a mutant variant of the coronavirus, which has prompted strict lockdown measures across England and led neighboring countries to put up trade and travel restrictions to protect against its spread. The conversation has been edited and condensed.

How unusual is this virus mutation?

SF: As far as viruses go, it’s not unusual to see mutations like this. They happen all the time, even within the same person. In fact, there have already been some 4,000 different documented mutations in the Sars-Cov-2 virus that causes Covid-19 as it has spread around the globe. Until now, none have been a real cause for concern. But the latest one that has been discovered in the U.K. is potentially worrisome, and I believe the government’s action in imposing severe lockdowns in London and southeastern England is warranted until more information is available.

The U.K. government says it took its action on lockdowns in part because the new variant may be as much as 70% more transmissible than original strains. What evidence is there of that?

SF: There is little hard data to prove that the new variant is transmitted more easily. The rapid rise in the number of cases in southeastern England may simply be because the virus was at the right place at the right time, just as was the case with a variant — so-called D614G — that was subsequently shown not to have better transmission but still became the dominant version of the virus in the U.S. and Europe. Also, one of the mutations related to this new variant has previously been shown to actually reduce transmission. So it’s just too early to know whether the spread is just luck or the result of a biological property of the virus. Without more information, though, it’s best to take these added precautions.

Does this variant cause a more severe form of Covid-19?

SF: Again, there are no hard data to suggest one way or another, but it’s very early days. Data on overall case counts relative to hospitalizations and mortality will in the next few weeks be able to provide preliminary clues. But definitive answers will need deeper study as there are many other confounding drivers of hospitalizations, such as the fact that infections are occurring in a colder climate, which is generally associated with weaker immune systems. Again, the mutation now dominant in the U.S. and Europe was thought to have 50% higher mortality, but that has turned out not to be the case.

What about vaccines? Is the immunity caused by the approved Pfizer Inc.-BioNTech SE and Moderna Inc. shots good enough to prevent disease from this variant?

SF: This is the big concern, but here’s what we know. This latest variant evolved with 17 mutations. Eight of these occurred in the part of the virus that’s targeted in the vaccines made by Pfizer-BioNTech and Moderna, as well as the shot in development by AstraZeneca Plc and the University of Oxford and many other companies. The working hypothesis of how this variant evolved is that it came from a chronically infected, immunocompromised patient who was treated with human convalescent plasma to protect against Covid-19. This gave the virus plenty of time to evolve in a way to allow it to grow despite the immune protection provided by the plasma. The problem is, that may also make it less sensitive to our current vaccines, given that the plasma therapy likely contained antibodies similar to those induced by the vaccines. Luckily, this is a relatively easy question to answer using blood from vaccinated individuals and laboratory experiments that look at how effectively this blood can kill the new variant. Also, given the high level of efficacy of the Pfizer-BioNTech and Moderna vaccines, a reduction from the 95% we have seen so far to even 60% or 70% would still mean a very good level of protection. Also, vaccine trials underway by AstraZeneca and Novavax Inc. include large numbers of subjects in Britain and can directly answer this question in the next few weeks. The U.K. rollout of Pfizer-BioNTech’s vaccine will allow a similar analysis.

Source link

By admin

Leave a Reply

Your email address will not be published. Required fields are marked *