Norovirus Vaccine: Why We’re Not Holding Our Breath

If you’re anything like me, you’ve been absolutely terrified about the possibility of norovirus entering your home. Yes, the gastrointestinal virus makes its rounds every year, but this year’s prevalence and severity seem especially nasty. If your TikTok feed looks anything like mine, everyone and their mother (literally) is battling norovirus, complete with vomiting, diarrhea, stomach cramps, and more unpleasant (to put it mildly) symptoms.  

Norovirus is often referred to as the “stomach flu”, but the truth is, it’s not related to influenza in any way. It’s a gastrointestinal virus, so while it spreads from person to person like respiratory viruses, it mostly causes gastrointestinal symptoms. It’s not going to cause, say, a runny nose (though some people do get fevers, headaches, and body aches). 

Many people also report being exhausted even after the worst of the vomiting and diarrhea have passed — and not surprisingly, dehydration is a real concern when you can’t keep even water in your system.

The current norovirus season seems bleak

It feels as though norovirus has been a topic of conversation more so than ever this year — between so many social media testimonials about the “virus from hell”, countless headlines indicating that cases are on the rise, and maybe even people you know IRL telling you they’re down with the stomach flu, it’s very (very) easy to feel like norovirus is thriving harder than ever at the moment.

It’s hard to say whether norovirus has mutated in such a way that it’s spreading even faster and wider than it typically does, or if it simply has peaked earlier this year than is typical. But we do know this: Norovirus is always around. It’s more common during the winter, but anyone can catch it at any time. You can also catch it multiple times according to the CDC, as there are multiple different types of norovirus.

So…that’s delightful! And it begs the question: If immunity-via-infection isn’t enough to protect us against repeated bouts of norovirus, can we get protection via a vaccine? 

Well, sadly, the answer is no…at least not yet. 

Norovirus vaccine efforts are underway, though

Pretty much every time I come across a social media post about norovirus, the reaction is the name: “Why is there no vaccine for this?” 

The good news? Efforts to develop a norovirus are underway. The bad news? It won’t be available this year… and we can’t really say when it will be available. 

Here’s what we do know: Moderna is inching closer to rolling out an MRNA vaccine. In September 2024, Moderna released news that the first dose of the vaccine had been dosed via an ongoing clinical trial. 

But why aren’t we even closer?

Now, norovirus has been around for a long, long time, and people may wonder why we’re not closer to a widely available vaccine already. Of course, vaccines take time to develop and test, but when it comes to norovirus, the demand is certainly there. 

Here’s the thing, though: While norovirus is absolutely miserable when it afflicts you, it’s typically over within one to three days, and doesn’t cause long-term harm in the majority of cases. 

“There are a couple challenges [with prioritizing a norovirus vaccine]. One is that it’s a disease that’s incredibly uncomfortable when you have it but for most people, it’s self-limited and short-lived,” Moderna’s clinical therapeutic area head, gastrointestinal and bacterial pathogens, Doran Fink, MD,  says, according to Fortune. “The focus on vaccine development has been on diseases that are causing a higher rate of hospitalizations and deaths. So it’s been, in part, a matter of priorities.

That’s not to say it can’t have larger effects — the virus is potentially (though rarely) fatal, especially in vulnerable populations, per the CDC. On top of that, the burden of norovirus is very real: It can rip through schools, childcare centers, long-term care facilities, hospitals, restaurants, and most famously, cruise ships, which has a serious ripple effect on people’s jobs and daily lives. 

But, once again, it typically only affects someone for one to three days — which, granted, can feel like an eternity when you’re confined to the bathroom, experiencing nasty symptoms, and unable to eat or drink anything.

For now, all we can do is protect ourselves against this nasty little bug

…Which is easier said than done, unfortunately. Norovirus is notoriously hard to defeat. For example: Did you know hand sanitizer isn’t particularly effective against norovirus? According to the CDC, good, old-fashioned hand-washing is necessary to get the virus off your palms. And, regular household cleaners don’t stand a chance either: You need to use bleach — and if the virus enters your home, you’ll need to go through a thorough disinfection process (which is outlined here) in order to even stand a chance against everyone else in the house going down as well. 

Norovirus is also resistant to heat, and food contaminated with the virus looks, smells, and tastes completely normal, yet can quickly sicken people. By the way, part of norovirus’s danger lies in how easily and efficiently it infects people: People with the virus shed billions (yup, billions) of viral particles, yet it only takes a few particles to make someone sick. The route of contamination is also particularly disgusting: According to the CDC, you get norovirus by ingesting tiny particles of an infected person’s poop or vomit. 

So yes, the virus is nasty…and probably won’t go away completely even with a vaccine

The challenge of developing an effective norovirus vaccine — as is the case with vaccines for so many viruses — is accounting for all the variants of the virus. According to a report from CNBC, immunizing against norovirus is a challenge because the virus has so many different types: The Moderna vaccine can reportedly address the three genotypes that cause the bulk of norovirus infections, but unfortunately, the genotype that is causing many of this season’s infections is not covered.

This vaccine likely won’t eradicate all norovirus infections (how nice would that be?) and that isn’t even the goal: However, the vaccine may be able to make the virus more bearable and less dangerous for vulnerable populations — and hey, that’s better than no protection at all.

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Zara Hanawalt is a freelance journalist and mom of twins. She's written for outlets like Parents, MarieClaire, Elle, Cosmopolitan, Motherly, and many others. In her (admittedly limited!) free time, she enjoys cooking, reading, trying new restaurants, and traveling with her family.