how long it will continue to mutate and what will happen to the vaccines

The first news from China spoke of a virus that exceeded the usual parameters. It was then understood that in addition to the variant of the place where he was from -in Wuhan- the Covid 19 mutated and generated new worrying variants. Among them, Delta. Vaccines with different technologies have appeared, although all created against this first version of the coronavirus. Today, to the two doses is added the possibility of a third and the options in the world are diverse: combination vaccines, improved doses and up to one Nasal spray progress in the prevention of contagion. The specialists consulted by Bugle they answer on the chances of developing new mutations and the way forward in terms of vaccines.

“In the evolutionary process of the virus, mutations and new ones will surely keep appearing», Says Horacio Salomón, biochemist, doctor in virology and senior researcher at Conicet. Against them it is likely that next year “some vaccines are suitable so that the leakage of the immune response is less ”.

“This does not mean that the available vaccines stop working. I don’t even think the development of a new vaccine is so relevant today, although it is possible that the infamous third dose come with some improvements, for example, against Delta, ”he said.

In this sense, Pfizer has announced that it make a vaccine against the Delta variant. However, the CEO of the pharmaceutical company, Albert Bourla, told US broadcaster NBC that he didn’t think it was necessary. “The current vaccine against Covid 19 works very well against the variant,” he contributed in this regard.

The important thing about this third dose, according to Solomon, is that it acts as booster and increase the levels of neutralizing antibodies so that in case of contagion, the body quickly clears the virus. “There is still no hard data on when it would be practical to receive this vaccine. A good idea would be to guarantee a generalized strengthening one year after the second dose, ”he explains.

And he explains that it’s not clear either what will happen after delta, especially if other mutations occur that are beyond the body’s ability to defend itself. “It’s very difficult to make predictions. The key is now in complete diagramsThis is the way to prevent the virus from continuing to replicate on a large scale and, therefore, to continue to mutate, ”he adds.

Strains and variants

For Belkys Maletto, biochemist, doctor of chemical sciences and researcher at Conicet, it is not so easy to discuss the future of the coronavirus. “Although analogies are made between the Covid and the flu and this is why at one point there was talk of the possibility of offering a different vaccine each year, the truth is that the coronavirus behaves very dynamic and unexpected and we still cannot specify what will happen ”.

Most of the vaccines developed to date focus on the S protein (peak) or even in a part of this protein which is RBD. Is this the route of the virus to the body: through the spicule of the coronavirus, it is because the virus binds to the receptor of the cell and infects it. “This key with which the Covid is trying to enter has been slightly modified in order to evade the immune system. For a new vaccine to be necessary, a variant would have to emerge that drastically changes the S protein, it would almost be like to face a new virus “, he remarks and specifies that he considers it” unlikely “.

He agrees with Salomon that the available vaccines are effective against the mutations known to date. He also cautions that most of the conclusions about the new variants and immunity generated by the vaccines are drawn based on the humoral response (neutralizing antibodies). “And this is not the only defense we have”, underlines the expert, who is professor of clinical biochemistry at the Faculty of Chemical Sciences of the National University of Cordoba.

“The memory cell response it is generally not taken into account because it is more expensive to measure. But it must also be taken into account as a useful tool, ”he emphasizes. These are B lymphocytes, which are used to recognize the virus and generate antibodies, and T lymphocytes, which develop a series of molecules capable of attacking the coronavirus. “There is a study done on T lymphocytes which shows that its scope does not change with the emergence of new variants of concern ”, he comments and quotes a book published in the magazine Cell July of this year.

Alternative vaccines

According to Maletto, don’t think salvation is in a new vaccine. “Some details can be adjusted for a third dose, although this third dose can also be reinforced by the hand of heterologous vacunas. For example, that a person who has received two from Sinopharm adds a reinforcement from Pfizer, ”he summarizes. And he adds: “Even before the coronavirus, we knew that the combination of different vaccine platforms resulted in an improvement in the quantity and quality of antibodies. “

He claims that some vaccines can be refined, although he assures that it is impossible to track the Covid: “It is neither rational nor practical to change vaccines every two or three months, which is when a new variant emerges. “

The other limitation, according to Maletto, is that there are still countries without even a dose. “The World Health Organization (WHO) has already said, it is not advisable to give the third dose to some when there are others who have not yet received the first. And not only because of the consequences on this unprotected population, but also because in the territories where the virus circulates freely, the possibilities that new significant mutations appear», He confirms.

The element that could make the difference for the specialist is the development of a vaccine administered by the nasal route. “There are already clinical trials, although they are pending approval. It would be one more step to take upper airway immunity and thus advance not only against serious diseases but also on the prevention of infections, ”he concludes.

MG