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

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

It is difficult to say because they have not been compared directly in the studies. But experts say vaccines are similar in what matters most: preventing hospitalizations and deaths.

“Fortunately, all of these vaccines appear to protect us from severe disease,” said Dr. Monica Gandhi of the University of California, San Francisco, citing the results of studies for five vaccines used worldwide and a sixth that is still ongoing. examination.

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

However, people may wonder if one is better than the other, as studies conducted before the launch of vaccines found different levels of effectiveness. The problem is that it does not provide comparisons between apples and apples.

Consider the two-dose vaccines from Pfizer and Moderna, which have been shown to be approximately 95% effective in preventing disease. Studies for these photos counted a COVID-19 case if it was mild, moderate, or severe – and were done before worryingly mutant versions of the virus began circulating.

Then, Johnson & Johnson tested a single-dose vaccine and did not count mild diseases. J & J’s hit was 66% protection against moderate to severe disease in a large international study. Only in the USA, where there is a smaller spread of variants, it was 72% efficient. More importantly, once the effect of the vaccine began, it prevented hospitalization and death.

The AstraZeneca two-dose vaccine used in many countries has been questioned about the exact degree of its effectiveness indicated by studies. But experts agree that these photos also protect against the worst results.

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