Reacción a "Expert reaction on the new variant B.1.1.529 detected in South Africa"

What do we know about this new variant?

Very little so far. On the one hand, it accumulates a large number of mutations in the spicule, including some that we believe are associated with increased transmissibility and others associated with reduced antibody efficacy. However, as they have never been seen together, we cannot know whether this is really the case or not. Experiments are already being carried out to tell us whether the response to antibodies is similar or not, and in parallel we are looking at its epidemiological growth rate, which will allow us to know whether it has greater or lesser transmissibility than Delta. The fact that for the moment it has been seen growing rapidly in South Africa, displacing Delta, does not necessarily indicate an advantage in transmissibility. We have to wait to see what course it follows in South Africa and, above all, compare with other countries, to see if it makes a niche for itself or not.

For example, Beta was one that we were very concerned about at the time but it never took off beyond South Africa. Therefore, we need to see what trajectory it follows in countries with different epidemiological situations (vaccination, growing or declining cases, etc.). It is true that in South Africa a rapid identification test is being used (genomic sequencing takes some time) and it does seem to be growing at a very fast rate.

Does it deserve special attention in your opinion?

Yes, it does. Not so much because of what we know, which at the moment is little, but because of the potential of the combination of mutations we see. Many of them we have seen in other variants of concern. We must follow it and see whether we are in a scenario like with Delta a few months ago, or it is a false alarm. We must have the ability to identify these potential threats, follow them and assess them. The vast majority come to nothing but some, like Delta, have displaced earlier variants making epidemiological control a little more difficult. In any case, now more than ever, it should be remembered that prevention is based on multiple layers, all of them imperfect but together very good. The best layer we have is vaccines but with Delta we have seen that they do not stop transmission sufficiently. However that does happen when we add masks, distance and ventilation. And that lesson applies to any variant past, present and future.

In light of what is known, could it affect the effectiveness of vaccines?

We don't know yet, we have seen some of the more worrisome mutations in that regard in other variants before, but we also know that it is the combination of all the mutations, how they combine in a particular variant, that determines its behavior. Some mutations in this variant we know that reduce antibody neutralization because we have seen them before. It is not good news, but the immune response also includes the cellular response, which we all have but it is rarely measured because it is not easy. What we do know is that variants carrying some of the mutations reduced effectiveness a little bit but not greatly and there was still good protection against hospitalization and death.