The arrival of the COVID-19 caught us off guard. In fact, we continue to pay the consequences of that lowering of our guard. For this reason, it is important to monitor the places where new viruses that could lead to pandemics could emerge. One of the largest reservoirs of pathogenic viruses, especially coronaviruses, are bats, which is why scientists from all over the world sample viruses extracted from their organism. And that is how they discovered the Khosta-2a virus belonging to the same subgenus as SARS-CoV-2 that has brought us so many headaches.
Those responsible for the discovery are a team of scientists belonging to the Washington State University Paul G. Allen School for Global Health. As reported in a study published in PLOS Pathogens, the first thing they did was check if they could infect humans. And unfortunately they saw that it does have the ability to enter our cells. Furthermore, existing vaccines do not appear to be effective against them.
For this reason, the recommendation of these researchers is that, instead of putting all the effort into developing vaccines against SARS-CoV-2 variants, effective alternatives against the sarbecovirus. That is, against that subgenre to which both the cause of COVID-19 and Khosta-2 belong.
Khosta-2, like Khosta-1, was isolated from Russian bats in 2020. At first it seemed that they did not have the ability to infect humans, so they were not a concern. We had enough that year with what we had.
However, over time it was discovered that Khosta-2 has the ability to penetrate our cells. That’s bad news, but what exactly does it mean?
The key is in the spike protein, which we have heard so much about with the COVID-19 coronavirus. This protein is the key that viruses use to enter the cells of their hosts. In turn, the cells have different receptors, which are like the lock in which that key fits. The Khosta-2 spike protein has been shown to fit into the ACE2 receptors, which are precisely the same ones used by SARS-CoV-2. That means they can enter our cells. And, perhaps, it could also mean that the vaccines that have been developed against COVID-19 may be effective against it. After all, what these vaccines do is cause antibodies to be synthesized against the spike protein.
The problem is that, although they may fit the same lock, the spike proteins of both viruses are not exactly the same. They couldn’t be sure, so they had to test. First, they exposed the virus to samples of serum from people vaccinated against COVID-19. This means that they exposed the virus to antibodies that had been synthesized against SARS-CoV-2. Unfortunately, they failed to neutralize the virus.
There was still hope that naturally synthesized antibodies might be more effective. Therefore, they repeated the process with serum from people who had passed an infection with the Omicron variant. Again, no result.
Two bad news and two good
So far we only have bad news. On the one hand, that Khosta-2 can penetrate human cells. And, on the other, that the vaccines we have against the COVID-19 coronavirus are not effective.
However, these scientists have also found two pieces of news to be optimistic. The first is that, even though it can enter the cells, it seems that it is missing some of the genes that would confer pathogenicity against humans. It is useless that the virus can enter the cells if it is not capable of taking over our replication machinery and start making copies with it. And it seems that he is not able to do it.
Also, the latest good news is more of a reflection. This time they have arrived on time. The virus has been discovered before it infects humans, so science can anticipate its movements. Rather than take this news as something apocalyptic, we should be glad that, little by little, we are learning to monitor some of the viruses that surround us. If the techniques used in this continue to improve and the financing does not stop, it could be that the next epidemic does not catch us off guard. Who knows? Perhaps it will even be possible to prevent it from becoming a pandemic.