Why comparing the effectiveness of the COVID-19 vaccine can be misleading, experts say

The most important thing to know in a pandemic context and the universal idea of ​​protecting in a global health emergency is that the best vaccine is always the one available. In the United States, three vaccines are distributed across the country: Inoculant Pfizer / BioNTech, Moderna and Johnson & Johnson.. All three are highly effective at what matters most: preventing hospitalizations and deaths from COVID-19. But some people are skeptical of Johnson & Johnson’s option of having a lower efficiency figure.

Even the mayor of Detroit, the largest city in the state of Michigan, Mike Duggan, rejected 6,200 doses of Johnson & Johnson’s vaccine this week. “J&J is a great option, but Moderna and Pfizer are better“Said the official at a press conference and added:” I will do my best to ensure that the people of this city get the best. “

Now alright for scientists, this is not the right way to think about COVID-19 inoculants and to judge Johnson’s option inferior on the basis of its lower reported efficacy is misleading.

According to official figures compiled by Johns Hopkins University, the coronavirus has killed 523,238 people in North America, and the total infected nearly 29 million. The nation leads both world rankings, both for confirmed cases and deaths. Despite the fact that the new positives clearly appear to be declining, the SARS-CoV-2 virus continues to spread rapidly and the new variants are spreading around the world, raising growing concern among experts over the imminent extension of the virus. disease. Pandemic, despite rapid or slow, but brief vaccination campaigns. This is why denial of vaccine doses when supplies are tight is undermining the campaign to fight the pandemic.

Based on available data, in clinical trials vaccines produced by Pfizer / BioNTech, Moderna and Johnson & Johnson reduces COVID-19 death rate by 100%, compared to the placebo groups. In turn, they kept anyone who received the antidote out of hospitals. This means they could make the coronavirus a manageable problem, when it comes to managing and managing disease from a public health perspective.

For Amesh Adalja, Principal Investigator at the Center for Health Security at the prestigious Johns Hopkins University, “The goal of a vaccine is to domesticate SARS-CoV-2 so that it looks more like other respiratory viruses we live with, so when you look all three vaccines approved in the US, all extremely good at this point“.

However, there are important differences to note in vaccines. Johnson & Johnson is single dose, requiring a single dose, while Pfizer and Moderna are both. At a time, can be stored at conventional freezing temperature (2-8 ° C), unlike that of its two competitors, which require ultra-cold temperatures (-80 to -60 ° C and -25 to -15 ° C respectively). In addition, there is a discrepancy in the values ​​of inoculants: Johnson costs $ 10 per dose, while Pfizer has over 20 and Moderna costs $ 25 to $ 37 per dose.

These are significant advantages in terms of logistics for the benefit of the J&J option. This was declared to the specialized media Vox Saad Omer, director of the Yale Institute for Global Health, “this immunization option can increase equity“, because J&J vaccine could reach harder-to-reach places.

When you apply for United States Government Food and Drug Administration Agency (FDA) approval for your COVID-19 vaccine, Johnson & Johnson reported that its overall effectiveness in preventing cases of the novel coronavirus was 66.1%, a figure significantly lower than those recorded and reported by Pfizer and Moderna, around 95%. This difference when it comes to talking about efficiency has led some Americans to talk about an option that “falls short.”

Now alright scientists believe that these numbers cannot be compared fairly to each other. And that’s because the efficacy levels of COVID-19 vaccines are specific to the clinical trials they’ve been subjected to., and these technical scientific assessments have been carried out in different ways.

Additionally, U.S. health officials have pointed out that the most important numbers – that is, prevention of hospitalizations and deaths – are consistent across the board and perhaps more comparable. Since they started to be distributed, researchers note that vaccines do a remarkable job of keeping people with the disease.

For him Adalja concluded that “the best COVID-19 vaccine for the vast majority of people is the one they can get“, And that” they are fundamentally interchangeable “.

The points of comparison

To measure the effectiveness of inoculants, Pharmaceuticals test them at different stages and phases, where they make sure they are safe, look for the correct dose, and try to determine the degree of protection they provide.. These clinical trials are designed to test vaccines individually, it is not intended to test them against each other. This is why direct comparisons do not always make sense.

That’s how he expressed it Anthony Fauci, director of the National Institute of Allergies and Infectious Diseases, on the J&J vaccine, last January: “If this had happened before other vaccines were announced that were 94.95% effective, it would have been said that 66% effectiveness is an absolutely spectacular result.“.

In their Phase III trials, the vaccines were tested against the virus in the real world, in people “in the flesh”, which involves monitoring tens of thousands of participants for their symptoms, which in turn. are divided into randomized groups who inoculating real and those who received a placebo (randomized double-blind).

In addition, Johnson & Johnson’s efficacy results included trials in other countries, while Moderna and Pfizer / BioNTech’s results mainly came from US participants. J&J found that the effectiveness of the vaccine changed depending on the country in which it was studied. The vaccine was found to have a 72 percent overall effectiveness after four weeks in preventing symptoms of COVID-19 in the United States. Under the same criteria in South Africa, where a variant of the coronavirus with disturbing mutations that help it evade vaccines has spread widely, the company found an efficacy of 64%.

Researchers will have to find out now the performance of existing vaccines against variants, mutations and new strains in the real world. Although clinical trials of vaccines have been conducted independently of each other, “scientists should now coordinate, sharing protocols and pooling data to draw more useful conclusions,” warn the experts.

“Imagine what will happen when these studies produce results, each with their own populations, eligibility criteria, validation procedures, and clinical criteria.», He alerted Natalie Dean, assistant professor of biostatistics at the University of Florida, in the scientific journal Nature. “If we don’t want our final answers to be unintelligible, we must act now to examine how data can be compared and combined,” he recommended.

In the meantime, it’s important to note that vaccines are part of a comprehensive public health management response to COVID-19. Social distancing, handwashing, the use of masks, diagnostic testing, follow-up and isolation remain key to accelerating progress towards ending the pandemic.

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