Vaccine Efficacy: Are Some COVID-19 Vaccines More Effective Than Others? What is known about studies by Pfizer, Modera, Johnson & Johnson?

NEW YORK – Are Some COVID-19 Vaccines More Effective Than Others?

It’s hard to say because they weren’t directly compared in studies. But experts say the vaccines are the same for what matters most – preventing hospitalizations and deaths.

“Fortunately, all of these vaccines look like they protect us from serious illness,” said Dr. Monica Gandhi of the University of California, San Francisco, citing study results for five vaccines in use around the world and a sixth still in use. assessed.

And realistic evidence, as millions of people receive the vaccines, shows that they all work very well.

Still, people may wonder if one is better than the other as studies conducted before the vaccines were rolled out found varying levels of effectiveness. The problem is they don’t compare apples to apples.

Consider the two-dose vaccines of Pfizer and Moderna, which have been found to be about 95% effective in preventing disease. Studies for those shots counted a COVID-19 case, be it mild, moderate, or severe – and were conducted before worrying mutant versions of the virus started circulating.

Next, Johnson & Johnson tested a single-dose vaccine and didn’t count mild illnesses. J & J’s shot was 66% protective against moderate to severe disease in a large international study. Only in the US, where there are fewer variants, was it 72% effective. More importantly, once the effect of the vaccine started, it prevented hospitalization and death.

The two-dose vaccine of AstraZeneca used in many countries has raised questions about its exact degree of effectiveness, as studies show. But experts agree that those shots also protect against the worst results.

Around the world, hospital admissions are declining in countries where vaccines have been rolled out, including Israel, England and Scotland – regardless of which injections are given. And the U.S. government’s first look at real-world data among key workers provided further evidence that the Pfizer and Moderna vaccines are highly protective – 90% – against infections, regardless of whether there were symptoms or not.