What is the future of Covid?

• Covid-19 The seventh Covid wave arrives, revenues increase by 78% in one month

• Coronavirus How likely is it that a new dangerous variant of Covid will emerge?

Although we are immersed in the

, the truth is that since the vaccines arrived or, rather, since their administration began to advance, we have relaxed a lot thanks to their

.

The truth is that people continue to die and Covid is still among us: infections continue to increase and the number of hospitalized is similar to that of four months ago.

With each new wave it is increasingly difficult to find someone who, regardless of vaccination, has not been infected.

And the situation we are in today has nothing to do with the one we were in a year or a year and a half ago, for example.

Now practically almost everyone is vaccinated [92.7% of the population over 12 years of age have two doses and 53.5% over 18 years of age have a booster], there are many who have been vaccinated and infected and are a minority those who have not been vaccinated or infected, in the words of Agustín Portela, head of the Division of Biological Products, Advanced Therapies and Biotechnology of the Spanish Medicines Agency (Aemps).

This is how his presentation began

one of those that took place at the

organized a few days ago by the Surveillance Group of the Spanish Society of Epidemiology (SEE), in which participated, among others, Pilar Aparicio Azcárraga, general director of Public Health of the Ministry of Health;

Marina Pollán Santamaría, director of the National Center for Epidemiology;

o María José Sierra, number two of the Center for the Coordination of Health Alerts and Emergencies (CCAES).

During the conference, public health surveillance was vindicated as the most effective instrument to detect, control and prevent future pandemics, and for this several demands were put on the table, such as the need for

.

One of the tables was dedicated to reviewing the lessons learned after the Covid pandemic and that is where Portela, who is also responsible for the Clinical Evaluation Unit for Vaccines for Human Use, spoke about

.

Lessons learned from Covid

The specialist began by reviewing issues that have become apparent in this time of pandemic.

Although SARS-CoV-2 encodes more than 25 proteins, all the

authorized in the European Union

(spicule, known as S), which is what allows the virus to bind to the cell to through the ACE2 receptor.

"Without that union, the virus does not infect," Portela pointed out.

Therefore, the immune system of a naturally infected person and a vaccinated person respond differently (as happens with other viruses):

.

In this way, Portela indicated, the protection in people who have been infected or infected and vaccinated (hybrid immunity) is going to be much greater than in people who have only been vaccinated.

Hence, the expert advocated focusing surveillance tasks on those who are only vaccinated.

The protection provided by the vaccine against mild disease decreases over time

(in the case of omicron, it practically disappears after 24 weeks, although with a third dose it recovers and there is high efficacy), but

.

The vaccine does not prevent reinfections, but it does prevent serious infections, stressed Portela, who linked it to

: the greater the number of these, the more protection.

In addition,

.

"Once we have come into contact with the first antigen, there are memory cells that, when they meet the antigen again, quickly produce antibodies, each time with greater affinity. By having antibodies of greater affinity, with less quantity we can neutralize the same amount of virus".

This explains that the first time you are in contact with the virus, it begins to multiply in the upper respiratory tract and the low-affinity antibodies take about 20 days to neutralize the virus, so while the virus reaches the airways lower respiratory tract and cause severe illness.

When there are more contacts with the virus, the immune system acts earlier, in less than a week (5-7 days), neutralizes it and prevents it from advancing to the lower respiratory tract.

And

, Portela stressed.

In this sense, the expert also explained how it is possible that with all the variants that have existed and with the vaccines being based on the protein S of the Wuhan strain, our immune system recognizes the virus.

"There is another mechanism that has been known for a long time, which is somatic hypermutation. Memory cells have a mechanism whereby when they meet the antigen again, they generate a wide variety of different antibodies. In other words, what happens

and that is why, although we have not been vaccinated against the omicron strain, we have antibodies against it".

Three possible scenarios

After this review, Portela spoke of the

and placed three scenarios.

.

"The virus surprises us with the plasticity it has to accumulate mutations and remain viable. But as long as there are neutralizing antibody titers in the sera of the vaccinated that recognize a new variant, there may be a wide circulation of the virus but not an increase in cases. serious (hospitalization, ICU, death), as long as we have that certain recognition".

Another much more speculative and complicated scenario, according to the expert, is

.

"It's very unlikely, but if it did happen there could be a change in tropism, the virus could infect other cells."

In that case, Portela pointed out that there could be some protection against the severity of the disease "thanks to antibodies that recognize other places on the Spike."

The specialist emphasized that it

, although he indicated that every time a new variant comes out, scientists describe whether it binds to ACE2 or not, that is, they do not rule out that this could happen.

The third scenario, "a very tremendous thing that we hope doesn't happen," would be

.

"This is very, very unlikely, they are very small proteins, but if this were to happen we could also have a change in tropism and disease. In that case, there would be some protection against gravity thanks to the antibodies that recognize other proteins of the virus in those people who have been infected. And those who have

because they would never have seen that protein," added Portela.

Focus surveillance on newborns

Knowing that the vaccine does not prevent infection and that there are many people who have already been infected several times, the Aemps specialist raised some questions: "When we have all been infected multiple times with all the possible variants of SARS-CoV-2 Do you think the virus will continue to circulate? Where should

be carried out ?

According to Portela, in

: flu, respiratory syncytial virus, when there were no vaccines, measles... For them and for their parents."

The specialist compared the gravity of

.

"They are

. The infection in children and adults is different. At the moment when there are many people infected, to be able to infect a vaccinated person and that has already gone through the infection, the virus needs an immune escape variant, which is capable of escaping that immune system and the entire wide range of antibodies generated".

On the other hand, in the case of children it is not like that, he stressed.

"Children are protected for the first few months by the antibodies transmitted to them by the mother, but as soon as that is over

."

For all these reasons, although it is a group that is not closely monitored because it is understood that it cannot cause serious disease, but in case this mechanism occurs, the expert recommends future surveillance in newborns and unvaccinated children.

Conforms to The Trust Project criteria

Know more

• Coronavirus

• covid 19

• Infectious diseases

• Respiratory diseases

• Vaccines