If, for example, you receive the Pfizer vaccine in Mexico it may not be the same as if you receive it in Turkey, assuming that if you receive it in Mexico it is because you live in Mexico and if you receive it in Turkey it is because you live in Turkey. Let’s see. When we heard that the Pfizer vaccine showed an efficacy of 94.5%, it was like this because during the experimental phase 170 of the 43,661 volunteers who received the application (some of the “real vaccine” and others of the “fake vaccine” or placebo) They were the ones who fell ill with Covid 19 and of those 170 only eight had received the true one and the other 162 received the false one. Comparison between these figures resulted in an efficiency of 94.5%. If there had been no difference in the proportion of patients between the two groups, the efficacy would have been zero, that is, zero, and by contrast, if there had been no patient among those who received the real vaccine, but there were in the other group then the efficiency would be 100%. So far so good but it turns out that in the real world things can (and usually) be different, as it turns out that the groups of volunteers for this type of research are not a fully representative sample of the general population, since they are not included In experimental studies, certain groups, for example, pregnant women or people suffering from serious or chronic diseases, so that the results of the application of the vaccine in the open population of a Country will not give identical results to those of the studies, but Even beyond these circumstances, there are other factors that influence the result in the general population, such as the speed with which the vaccination program planned by the governments is fulfilled as well as the proportion of people who were not vaccinated, either because they rejected be it or because the calls and the promotion of vaccination were not successful for all geographic corners and also depending on the ca ntity of people who, due to having been vaccinated, relax or abandon protection measures to avoid contagion and transmission of the microbe in question, such as the use of face masks, hygiene, etc. Thus, to express the benefit of the vaccine, one speaks of efficacy, but to measure the results of the vaccination, one speaks of effectiveness, which refers in the jargon of immunizations to the best or worst result of the vaccination strategy, where appropriate. that despite a vaccine with excellent efficacy the impact of vaccination may be weak due to a mediocre vaccination strategy, or else, the case that a moderate efficacy vaccine could result in a high impact because the vaccination strategy was excellent . The pace, speed and extent of vaccination can cause a vaccine to perform better or worse than would be expected based on the efficacy of the product alone. It is well said that “vaccines do not save lives” and that, instead, “vaccination programs do save lives”. It is not the same to vaccinate before than after, to vaccinate at a good pace than slowly, to vaccinate few than many. And globally, special care will have to be taken: In Africa, especially in its southern region, the most dangerous variant of Covid 19 has already arrived and is multiplying infections that are also more deadly, but what has not arrived is the vaccine and it is not seen that it will arrive in the next months. This panorama is catastrophic and very contrasting with the expectations in the richest countries, but also, if vaccination is not carried out quickly in Africa, the new strain will jump to the rest of the continent, and in fact, to the rest of the world. Inequality takes its toll on everyone. Let’s see if we understand that way.
firstname.lastname@example.org Cardiologist from UNAM. Master in Bioethics.