Why Pfizer’s order for a third vaccine booster dose sparked controversy and controversy with the FDA and CDC

No doubt the Pfizer announces its impending application on July 8 wing United States Food and Drug Administration (the FDA) so that the use of a third dose of your vaccine is allowed, this has caused some confusion.

The pharmaceutical company argued that recent data obtained in Israel revealed that, in relation to the response to the Alpha variant, the vaccine’s efficacy in protecting against symptomatic disease caused by the Delta variant decreased from over 90% to 64%. He added that in his experiments a third dose produces 5-10 times higher levels of neutralizing antibodies than those which occurred after the second dose and planned that the third dose could be given 6 to 12 months after the second.

Because the possibility of a third dose had been discussed for a few months, Pfizer’s announcement gave the impression that the booster dose of the vaccine may soon become a reality. But controversy arose when, unexpectedly, and within hours of Pfizer’s announcement, the US Centers for Disease Control and Prevention (the CDC) and the FDA they said in a joint declaration that “until now there was no need for a third dose for the American population”.

To understand this controversy, we must remember how the effectiveness of a vaccine is measured. The efficacy of a vaccine results from its comparison with a placebo in a phase III study, while efficacy is assessed by comparing vaccinated and unvaccinated people in a real-life national immunization program.

In this sense, among the different ways of measuring the effectiveness of a vaccine in real life, three stand out: 1, the effectiveness of a vaccine to protect us from infection and mild symptomatic COVID-19. 2 °, the effectiveness of a vaccine to prevent that, if it infects us, it is serious and takes us to the hospital. Yes 3, the effectiveness of a vaccine so that disease does not cause us death.

The efficacy of a vaccine is obtained by comparing a vaccine to a placebo in a phase III study.

The point is, while some studies have shown that vaccines, including those from Pfizer, are less effective in preventing mild symptomatic illnesses, the effectiveness of protection against serious illness and death, fortunately, has not changed substantially.

This then explains the immediate response from the CDC and the FDA., who said that, for this reason, now is not the time to have a third dose in the united states and its eventual need would be determined after a rigorous process based on science and evidence.

This scientific process, they said, takes into account several laboratory data, of clinical tests and from cohorts or large population groups, which may include data from pharmaceutical companies. This is why they conclude that the need for a third dose does not depend solely on studies from a single pharmaceutical company.

In addition to the CDC and the FDA, The World Health Organization (WHO) and the European Medicines Agency (EMA) spoke on July 9, saying that there is currently no scientific basis for giving a third dose..

The CDC and the FDA also say that The United States is fortunate to have very effective vaccines that are widely available for ages 12 and up., and that fully vaccinated people be protected against serious illness and death, even against variants currently circulating in the country like the Delta.

No doubts, The big problem in the United States is that unvaccinated people are still at risk, since according to data cited by different health authorities, virtually all hospitalizations and deaths from COVID-19 occur in this group..

WHO and EMA have also said that there is currently no scientific basis for administering a third dose.

In this regard, it has been observed that in the United States, the Delta variant has spread faster in states where the population has not achieved the high vaccination rates achieved in most jurisdictions. For example, although they had more difficult times at the start of the pandemic, Arkansas and Missouri now rank first and second in daily infections and hospitalizations per capita in the United States, according to data from Johns Hopkins University.. Most of these events are caused by the Delta variant in unvaccinated people..

This can be explained because only 34.6% of Arkansans and 39.4% of Missourians had been fully vaccinated through July 6, compared to 47.5% nationally. It was recently reported that in the state of Maryland, 95% of new COVID-19 cases, 93% of new hospitalizations and 100% of deaths were in unvaccinated people.

This huge difference in vaccine coverage means that, in the words of the doctor, Antoine Fauci, White House COVID-19 Advisor, there are two types of population in the United States: protected areas, where more than 70% of the population has received at least one dose, and unprotected areas, where only 35% of the population is in this situation..

In short, rather than thinking about a third dose to avoid a symptomatic infection, the effort should be aimed at increasing the use of existing vaccines which are very effective in preventing serious illness and death.

Coronavirus Podcast Material: Fact vs Fiction, with Dr. Elmer Huerta, by CNN

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