Vaccine efficacy: Are some COVID-19 vaccines more effective than others? What is known about the Pfizer, Modera, Johnson & Johnson studios

NEW YORK: Are some vaccines against COVID-19 more effective than others?

It is difficult to say, as they were not directly compared in studies. But experts say vaccines are the same in what matters most: preventing hospitalizations and deaths.

“Luckily, all of these vaccines seem to protect us from serious disease,” said Dr. Monica Gandhi of the University of California, San Francisco, citing the results of the study of five vaccines used worldwide and a sixth that is still under review.

And real-world evidence, as millions of people get vaccinated, shows that they all work very well.

Still, people might wonder if one is better than another, as studies conducted before vaccine implementation found different levels of efficacy. The problem is that they do not offer comparisons between apples and apples.

Think of the two-dose vaccines of Pfizer and Moderna, which are about 95% effective in preventing disease. Studies for these shots counted a case of COVID-19 if it was mild, moderate, or severe, and were conducted before mutated worrying versions of the virus began circulating.

Johnson & Johnson then tested a single-dose vaccine and did not count mild illnesses. J&J’s shot was 66% protection against moderate to severe disease in a large international study. In the United States alone, where there is less diffusion of variants, it was 72% effective. Most importantly, once the vaccine effect started, he avoided hospitalization and death.

The two-dose AstraZeneca vaccine used in many countries has faced questions about the exact degree of its effectiveness indicated by the studies. But experts agree that these traits also protect from the worst results.

All over the world, hospitalizations are falling in countries where vaccines are being deployed, including Israel, England and Scotland, no matter what shots are fired. And the U.S. government’s first look at real-world data among essential workers provided further evidence that Pfizer and Moderna vaccines are highly protective (90%) against infections, whether there were symptoms or not.