Many countries have already started to put a third dose of coronavirus vaccines elderly or immunosuppressed people. It is, for example, the case of Israel. Others like United Kingdom, United States, Germany and Franceto get ready to do it soon. Meanwhile, some countries do not reach 1% of their vaccinated population.
Therefore, the who issued a statement yesterday asking that countries with sufficient economic power to acquire and administer that third dose change your mind and donate it to the nations that need it most.
With this, the debate that already existed on this issue only intensifies. And, while the pharmaceutical companies themselves talk about the need for a third dose, there are many experts in immunology who maintain that, at least for the moment, it is not necessary. Of course, it may be necessary within a year, as with other vaccines, which need booster dose. But, at least for the moment, these scientists argue that it is much more primordial donate vaccines coronavirus.
Why a third dose?
The advancement of the delta variant around the world has changed immunization plans. With the above, it was calculated that at least one 70% of the population of a country should receive coronavirus vaccines to achieve the group immunity, also known as herd immunity.
However, this new variant is much more contagious, so that firewall that vaccines suppose must be much larger. So much so that some experts place the percentage at 90%. This, in countries like Spain, where more than 10% of the population is children, makes it practically impossible to think about that figure. Furthermore, one would have to assume that everyone wants to be vaccinated. It is true that, fortunately, in our country the percentage of people who reject vaccination is very low, but not non-existent. For this reason, as numerous experts recently explained in a report by The country, perhaps the time has come to stop thinking in percentages and simply focus on vaccinate as much as possible.
But does that mean that we must resort to a third dose like Israel? Actually, at least for now, it doesn’t seem like it’s necessary. Although the percentages vary in the different studies that have been carried out, at the moment it seems that the protection against the delta variant of all coronavirus vaccines is quite high. It is lower than against the other variants and the second dose is much more necessary, since the percentage of effectiveness with the first is very low.
But, once complete, protection against mild illness is located between 60% and 88%, depending on the vaccine in question. And it is much higher for hospitalizations and deaths. It is true that in ICUs there are people with the complete regimen, but the percentages are very low and, in certain cases, it is because they have other risk factors.
Antibodies aren’t everything
Lately there is much talk that a significant drop in antibodies has been observed after vaccination in a few months. So, explained without context, this may seem worrisome. But it’s actually totally normal.
It is true that after contact of the immune system with a pathogen, either directly or with a simulation carried out by the vaccine, they are generated antibodies specific against him. These antibodies, if another infection occurs later, will be able to fight the infection faster. But that’s not all, because the immunity It consists of many other components.
Broadly speaking, when a pathogen enters the body, it will be recognized by a type of immune system cell, called B cells. These, after that first contact, follow two different routes. Some become plasma cells, which are the ones that synthesize the antibodies. Here begins the fight against that strange agent. A fight in which other components also participate, such as macrophages, or helper T lymphocytes.
As for the rest of B cells, they become memory cells, which will be prepared to trigger the entire previous process much faster in the event of a second infection. Therefore, antibodies are not everything. If we think of our immune system as a storage room, they are those things that we sometimes store, but that we actually know we may not use again, so we end up throwing them away. Of course, now we know where we can buy them, so in case we need them we will go faster for them.
Something like this happens with coronavirus vaccines. The antibodies are disappearing, but the memory cells remain. Therefore, if we face the virus in the future, everything will pass faster that if we met him for the first time and, continuing with the simile, we had to go from store to store looking for what we need to destroy him. Therefore, as long as this immunity beyond antibodies accompanies us, a third dose it is not so necessary. Perhaps specific cases should be assessed in immunosuppressed patients, for example, but do not do it in an extended way.
Yesterday himself, the new science minister of Spain, Diana morant, He recognized that we may have to vaccinate many more times. This does not have to mean that we need a third dose of the coronavirus vaccines.
It is one thing to understand that we may have to living with the virus and, therefore, vaccinate again in next seasons, and another that, in this same, we need one more dose. It may be that in the future it will be like a flu and only vaccinate most vulnerable people. Or that, for a time, we all have to do it.
The truth is that trying to talk about all this ahead of time is to venture to make claims about a virus that we do not know how it will behave. We must be cautious and see how the situation progresses. But there is something that we do know well.
According to data from Our World in Data, approximately the 29% of the world population has received a dose of the coronavirus vaccines. In Spain, for example, a 58% already have the complete pattern. However, there are countries where only 1% of its population have received any doses. Talking about a third dose when there are people who still have the first one so far away, may not be the most accurate. In the words of the managing Director from the WHO, Tedros Adhanom Ghebreyesus, “We cannot accept that countries that have already used most of the world’s vaccine supply use even more.”
The main reason, of course, is the health of these people. We should not have to look for another pretext, because there are no first and second lives. But even if we go beyond that overriding reason, it is also for the global good. More unvaccinated people mean a greater chance for the virus to mutate to variants of concern, such as delta. If we intend to cut him off, we should do it all over the world.
The virus does not understand economic resources or skin colors. Therefore, vaccines should not make a difference to this, either.