The mRNA Vaccine Revolution: How the Nobel-winning Research Changed Infectious Disease Prevention

Friday - October 6 2023, 13:44 UTC - 1 year ago

The Nobel Prize for Physiology or Medicine was awarded to Katalin Karikó and Drew Weissman for their research into mRNA technology, which was key to developing the mRNA vaccines from Moderna and Pfizer/BioNTech that have saved millions of lives. mRNA vaccines are easy to produce and can be used to target multiple diseases, including the flu. The National Institutes of Health has already conducted trials on an mRNA flu vaccine and found promising results.

Hello again from The Checkup! .

This week the Nobel Committee for Physiology or Medicine honored two scientists whose research into messenger RNA (mRNA) technology paved the way for much-lauded covid-19 vaccines. Katalin Karikó and Drew Weissman figured out how to tweak mRNA to prevent it from setting off an inflammatory reaction. Their discovery, first published in 2005, was key to developing the mRNA vaccines from Moderna and Pfizer/BioNTech, part of a vaccination strategy that saved millions of lives.

Most vaccines train the immune system by supplying the pathogen against which they’re meant to protect—either the entire pathogen or some crucial component. The mRNA vaccines work a bit differently. They provide genetic code that cells within the body can translate into proteins. In the case of covid-19, the vaccines contain mRNA that codes for the "spike" protein found jutting from the outer surface of the virus. The body then produces copies of that protein, and the immune system learns to recognize it.

When foreign mRNA are injected into the body, the immune system spots a threat and creates inflammation. Karikó and Weissman found that by tweaking the genetic code slightly, they could nearly eliminate this problem. When the pandemic began in 2020, scientists had already been using their method to develop mRNA vaccines for other infectious diseases, so it was relatively simple to pivot to covid-19.

What makes mRNA a game changer? The vaccines are so easy to produce. When manufacturers wanted to update their covid vaccines this fall, they simply had to swap in a new code. By swapping in different codes, they should be able to target different pathogens.

There are a couple of reasons multiple companies are focusing their mRNA efforts on the flu. First, current flu vaccines rely on viruses grown in chicken eggs or cells, a laborious process that takes months. Using mRNA for flu vaccination would eliminate the need to grow the virus and speed the process substantially. That might allow for a better match between the vaccine and circulating flu strains (because the strains could be selected closer to flu season) and a quicker response should an influenza pandemic occur.

The other reason is that researchers can add in mRNA for many different flu strains to create a vaccine that might provide broader protection. Last year, a team at the University of Pennsylvania tested an mRNA vaccine containing antigens from all 20 known influenza subtypes that infect humans. In mice and ferrets, the vaccine protected against strains that matched the vaccine and strains that didn’t. This year, the National Institutes of Health launched a clinical trial to test another mRNA flu vaccine that doesn’t contain multiple antigens, but is designed to elicit a response to a portion of the virus that isn’t as likely to change from year to year.

Flu is just the beginning. The list of diseases for which mRNA vaccines are being developed goes on (and on and on): malaria, HIV, Zika virus, Epstein-Barr virus, cytomegalovirus, herpes, norovirus, Lyme disease, Nipah virus, C. difficile, hepatitis C, leptospirosis, tuberculosis, shingles, acne, and certain types of cancer, to name a few.