Given our interest in both infectious diseases and vaccines, it is not surprising that we at ACSH have been following the progress of the first ever vaccine against norovirus, aka the stomach flu, or the cruise ship virus.
Norovirus is the second most common infection in the U.S. (second only to the common cold) averaging about 20 million cases per year, resulting in about 60 thousand hospitalizations and about 700 deaths per year. And it is estimated that this virus costs the US an astounding $5.5 billion in healthcare costs
ACSH s Dr. Josh Bloom, who spent many years doing antiviral research, is especially intrigued. He says, Norovirus is the perfect bug. It is generally considered to be the single most contagious pathogen in the world. It has been estimated that as few as 10 virus particles can cause infection. He continues, Although the disease is rarely fatal you might wish that it was when you have it.
And there is virtually nothing you can do to protect yourself. There is no vaccine and no treatment (except rehydration for severe cases). The virus is not only highly infective, but it is tough as nails, surviving conditions that would destroy other viruses. The best current advice (CDC) is to wash your hands, with which Dr. Bloom takes issue:Please. You can either wash or cut off your hands and it will make no difference. This damn thing will get you one way or another.
Enter Ligocyte, a Montana-based company that has been working on the world s first (and only) norovirus vaccine for many years. As their clinical trials have progressed, more evidence of efficacy has been demonstrated. So much so that the Japanese pharmaceutical giant Takeda purchased Ligocyte last year.
And the vaccine is exceeding expectations. In a presentation at the IDWeek meeting, David Bernstein, MD, of Cincinnati Children's Hospital Medical Center and colleagues reported that the Ligocyte/Takeda vaccine is performing very well.
In a phase I/II study, 98 people agreed to drink water containing a significant dose of the virus (and you do NOT want to know where this comes from ). Half received the vaccine and half got a placebo injection. Those who got the vaccine experienced a 52% reduction in symptoms.
Furthermore, 8.3 percent of those receiving placebo got severe symptoms vs. zero from the vaccinated group.
Dr. Bernstein says: "If the vaccine continues to prove as effective as our initial results indicate, it could be used for specific populations or situations - in those at a higher risk of severe disease such as the elderly or at high risk for infection or transmission such as in day care, people going on a cruise, those in nursing homes or in the military."
Dr. Bloom comments, These are very good results. Almost certainly better than initial expectations. And with some tweaking of the dose and possibly adding other viral strains it is likely to get better. His 2011 op-ed entitled New Vaccine May Give Norovirus the Heave Ho discusses progress as of two years ago, and is good background reading on this topic.
And for your edification (and amusement) today s Wall Street Journal features an article entitled 10 things cruise lines won t tell you, which is certainly germane to this topic.