Moderna’s new vaccine targets COVID-19, the flu, and RSV

The combination vaccine delivered positive results in a mouse study.

Moderna is developing a combination vaccine to protect against COVID-19, seasonal influenza, and respiratory syncytial virus (RSV) — and early results in mice suggest the shot could one day save you from multiple yearly jabs.

The challenge: Because the viruses that cause infections can mutate over time, vaccines for them may need to change, too — that’s why we have to get a new flu shot every year and why we’ll likely need a COVID-19 booster.

Getting people vaccinated is one of the best ways to prevent the spread of diseases, but it can be hard to convince people (especially people who are afraid of needles) to get one vaccine, let alone multiple shots every year.

It’s relatively easy to tweak an mRNA vaccine to target new diseases.

The idea: A combination vaccine allows people to protect themselves against multiple diseases without subjecting themselves to multiple shots — the MMR vaccine, which protects against measles, mumps, and rubella, is a common example.

Now, Moderna has announced that a combination vaccine for COVID-19, seasonal flu, and RSV showed positive results in a mouse study, triggering a “robust” antibody response.

Moderna hasn’t yet released any data on the mouse study beyond a single chart attached to a tweet, nor has it announced plans to trial the three-in-one vaccine in humans. (For one thing, the RSV and flu shots haven’t been proven to work yet.)

However, the components of the combination vaccine are all either in human trials as standalone shots (the RSV vaccine and the flu vaccine) or already authorized for use (the COVID-19 vaccine). 

A human trial of a 2-in-1 shot, combining the COVID-19 and flu vaccines, is also in the works.

The big picture: Moderna’s COVID-19 vaccine wasn’t just unique for being one of the first approved to fight the pandemic — it was also just the second mRNA vaccine authorized by the FDA (Pfizer’s coronavirus shot was the first).

These vaccines use a molecule called mRNA to deliver instructions to cells — in the COVID-19 vaccine, for example, they train our bodies to make harmless bits of the coronavirus that can trigger an immune response to the real thing.

The beauty of mRNA vaccines is that, once you have one that works, it’s relatively easy to tweak its instructions to target new diseases — and now that mRNA vaccines have proven themselves with COVID-19, Moderna may have an easier time developing shots against the flu, RSV, or any combination of diseases. 

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