A Norovirus Vaccine Is in Late-Stage Trials: What It Means for Thru-Hikers
Raise your hand if you’ve ever been personally victimized by Norovirus.
Norovirus, a highly contagious virus that causes gastroenteritis, is one of the most dreaded illnesses among thru-hikers. It spreads quickly, hitting communal spaces like shelters, privies, and campsites, leaving hikers sidelined with debilitating symptoms like vomiting and diarrhea. Now, an mRNA-based vaccine in late-stage trials offers hope for hikers and others vulnerable to outbreaks in close-contact settings.

When the pit toilet looks like this… sometimes it’s better to just dig a hole. Photo: Sprinkles
Norovirus in Nature
Norovirus is a stubborn and highly contagious virus that requires only 10 particles to cause infection. It can linger for days on surfaces like privy doorknobs, shelter floors, and tables — frequent touchpoints on heavily trafficked trails such as the Appalachian Trail and Pacific Crest Trail. Unfortunately, hand sanitizer is ineffective against it, and some water treatment methods fall short of removing it entirely.
Outbreaks are especially common in crowded shelters or during peak hiking seasons. While some tend to believe Norovirus spreads through contaminated water, the real source is likely improper handwashing and poor waste disposal practices by hikers. A CDC investigation on the PCT revealed widespread fecal contamination on shared surfaces, while water sources tested clean—highlighting just how crucial proper hygiene is to preventing transmission.

In other words, please wash your hands after you poop! Should that need to be said? Photo: Pacific Southwest Forest Service
For hikers, catching norovirus can mean days of debilitating symptoms, severe dehydration, and, in some cases, having to abandon their trek altogether.
How Does This Vaccine Work?
Moderna’s norovirus vaccine, currently in a phase 3 trial called Nova 301, is the world’s first mRNA-based vaccine for this virus. Using the same groundbreaking technology behind COVID-19 vaccines, it trains the immune system to recognize the virus by delivering instructions to produce virus-like particles that trigger an antibody response.
The vaccine targets three norovirus strains, aiming to provide broad protection. While earlier trials showed it generates a strong immune response, the current study involving 25,000 participants will determine its effectiveness in reducing severe illness and its duration of protection.
What Could It Mean for Hikers?
A successful vaccine could be a game-changer for thru-hikers in two main ways:
- Reduced Severity: Even if hikers catch the virus, a vaccine may reduce symptoms, making recovery faster and less debilitating.
- Fewer Outbreaks: Vaccinated hikers could reduce the spread in communal areas, reducing the number of Norovirus cases long-distance trails see each year.
Moderna aims for at least 65% efficacy, a threshold that would significantly mitigate the worst impacts of the virus. If trials are successful, the vaccine could be submitted for regulatory approval by 2026.
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Comments 5
How long before the Orange Menace and his cabal of corrupt incompetents put an end to that?
Orange Man Trump? …errr, better check your facts here…
Trump was all for the mRNA Covid shots, and could not stop bragging about it!
Remember Operation Warp Speed?
These shots are more appropriately called modRNA with the widespread use of pseudouridine as a substitute. Couldn’t get me anywhere near any of the pharma harma stuff. Foreign protein manufacturing in your body has and is a bad idea. Just look at real life results who took it for the last four years. You might not show symptoms till the worst happens.
Assessment of Myocardial ¹⁸F-FDG uptake at PET/CT in Asymptomatic SARS-COV-2 vaccinated and Nonvaccinated Patients (Published Journal Radiology Sept. 2023)
T. Nakahara, Y. Iwabuchi, et. Al
Measured ¹⁸F-FDG uptake with PET scans. (positron emission tomography (PET)
Study shows myocardial damages with uptake.
Included 303 nonvaxxed and 700 vaxxed.
Vaxxed had overall higher myocardial FDG uptake compared to nonvaxxed.
The uptake was observed in patients imaged in four date ranges. 1-30 days, 31-60 days. 61-120 days and 121-180 days after second vaccination, with increased ipsilateral axillary uptake in vaccinated vs. nonvaccinated patients.
Editor Emeritus, Dr. Bluemke in editorial noted “The main results…for asymptomatic patients vaccinated for COVID-19 before PET had about a 40% greater radiotracer activity in the myocardium than unvaccinated individuals. (Statistically) The P value was low, less than .0001, translated to only one time out of 10,000 would these results occur by chance.”
This is suggesting that mild myocardial inflammation could be more common than expected. F-FDG uptake was higher in all vaccinated quartiles with age adjustments. Further, the myocardial SUVmax (g/ml) does not recover with time and was even above the level on the unvaccinated in the 40 patients who only received one dose.
Hey Stephen! Thank you for your thoughtful comment. I appreciate you starting this conversation!
I’ve read the article you’ve linked and have a few thoughts on it.
It’s important to note that the study you mentioned observed mild myocardial ^18F-FDG uptake in vaccinated individuals, which the authors suggested could indicate low-grade inflammation. However, the researchers emphasized that the clinical relevance of this finding remains uncertain and requires further investigation. This means we cannot draw conclusions about significant harm or long-term effects based solely on these results.
Additionally, the study did not demonstrate a direct connection between mRNA vaccines and severe adverse outcomes, nor did it suggest avoiding these vaccines. Instead, it highlighted the need for ongoing research into how vaccines might interact with the body in subtle ways.
I think it’s essential to approach these topics with a clear understanding of the data and context. While everyone is entitled to their perspective, broad generalizations about “foreign protein manufacturing” and mRNA vaccines don’t align with the findings of the referenced study or the broader body of research. I appreciate the fact that the COVID19 vaccine became a highly politicized topic, and the fast-moving, tumultuous time surrounding the initial lockdown made it hard for easily-understandable and accurate information to be conveyed.
You mention pseudouridine and, to me, your statement about it reflects a misunderstanding or mistrust of the science behind mRNA technology (which, again, is totally understandable as it takes people years of targeted study and research to ever fully understand it! I am in no way claiming to be an expert, though I will say I have a degree in Chemical & Biomolecular Engineering from Johns Hopkins, and have spent time at least at the periphery of this topic).
Pseudouridine is simply a modified version of the nucleoside uridine, which is one of the building blocks of RNA. It is often used instead of natural uridine. This substitution enhances the mRNA’s stability and reduces its immunogenicity (the likelihood of triggering an unwanted immune response), making the vaccine more effective and safe. If I’m correctly understanding your comment, you’re suggesting that it is inherently harmful, potentially causing long-term or hidden effects. Studies and clinical trials have consistently shown mRNA vaccines using pseudouridine to be both effective and safe, with millions of doses administered globally and a strong safety profile. Assertion about “real-life results” over four years seems to imply that pseudouridine could and has caused long-term harm, but this is not supported by current evidence or the paper you have referenced.
Again, I understand this is a very hot-button issue for a lot of people, and I hope I haven’t offended you in any way by replying to your comment. I love seeing papers from reputable, peer-review sources used in discussions like these so I really do thank you for directing me to an interesting one! I just have to push back, as I think the conclusion you drew from it lacked a bit of context and overgeneralized the findings, particularly around the fact that no clinical evidence of myocarditis or significant cardiac dysfunction was observed in the individuals in the study.
Anyways, I hope you have a great rest of your day! Cheers, K
Yes, thank you for this respectful venture into understanding the the basis and benefits of this vaccine. Let’s be “safe” together…including in the ways we help each other make sense of our world.