After Covid Success, RNA Vaccines May Be Here To Stay

No RNA-based vaccine has been approved for any disease. Still, with no serious side effects reported thus far in thousands of volunteers who got the Pfizer drug, the findings are a sign that after years of uncertain promise, RNA vaccines could hold promise

- Tom Avril

PHILADELPHIA

When Drew Weissman first started injecting mice with genetic molecules called messenger RNA, it did not go well. Many of the animals became overwhelmed with harmful inflammation, and some died.

But Weissman solved that problem with a bit of clever biochemistry 15 years ago, working with then-colleague Katalin Kariko at the University of Pennsylvania. Now their work forms the backbone of two vaccines for COVID-19, including the one for which dramatic early results were announced this week.

The vaccine made by Pfizer Inc. and the German firm BioNTech SE, where Kariko now works, appeared to reduce the risk of illness by more than 90%, though the results were based on fewer than 100 confirmed cases of the disease. As the trial continues, some physicians are reserving judgment until they see evidence that the drug helps the elderly and others who are more vulnerable.

No RNA-based vaccine has been approved for any disease. Still, with no serious side effects reported thus far in thousands of volunteers who got the Pfizer drug, the findings are a sign that after years of uncertain promise, RNA vaccines may be here to stay.

The advantages of RNA could extend well beyond the rapid production of vaccines. As millions of high school students learn every year in biology class, the twisty molecules contain recipes for making proteins: the building blocks of life. In theory, that means they could be used to treat any number of diseases in which a person’s natural proteins are deficient in some way.