How is Johnson & Johnson’s vaccine different from Pfizer and Moderna?

Last Saturday, the United States added a third effective weapon to its arsenal against COVID-19, after the Food and Drug Administration (FDA) granted emergency use authorization for a vaccine developed by Johnson & Johnson .

The company said it would start shipping millions of doses earlier this week, and that would deliver 100 million doses to the United States by the end of June. In addition to the 600 million doses of the first two vaccines licensed in the country, manufactured by Pfizer-BioNTech and Moderna, to be delivered over the next four months, that should be enough to cover all American adults who want to be vaccinated.

The new vaccine differs markedly from the two already in use in the United States. Here are the differences:

One shot instead of two

The Johnson & Johnson vaccine requires a single dose, while the Pfizer-BioNTech and Moderna vaccines are given in two doses several weeks apart.

How it works

Johnson & Johnson’s vaccine uses a different method to prepare the body to fight COVID-19: a viral vector called Ad26. Viral vectors are common viruses that have been genetically engineered not to cause disease, but can cause the immune system to increase its defenses. To do this, the Pfizer-BioNTech and Moderna vaccines use messenger RNA.

How it works

Johnson & Johnson’s vaccine being considered very effective to prevent serious illness and death, just like the Pfizer-BioNTech and Moderna vaccines. It is also very effective in preventing the milder version of the disease, although somewhat less than these two. It appears to be doing well against the highly contagious variant B.1.351, first identified in South Africa, which has posed at least one other vaccine candidate problem.

Storage and handling

Johnson & Johnson’s vaccine does not need to be stored at extremely low temperatures like that of Pfizer-BioNTech. It can be safely stored in a normal refrigerator for three monthsMuch more than Moderna’s vaccine, which spoils after a month if not stored frozen.

Side effects

Johnson & Johnson’s vaccine appears to be less inclined Pfizer-BioNTech and Moderna vaccines to trigger the types of side effects that require post-injection monitoring, which may make it more suitable for use in wheeled vaccination centers, where the vaccination process goes unchecked. the patient gets out of his car. It has been reported that side effects tend to be more severe after the second dose is given, which is not necessary with the Johnson & Johnson vaccine.

© The New York Times 2021

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