Best news ever! A Norovirus vaccine that works!
As a parent or two young kids, I dread the slightest hint of nausea. Now, perhaps, I might have one less pathogen to fear and perhaps in old age, I can even take a cruise.In the recent NEJM there is a report of an RCT assessing the safety, immunogenicity, and efficacy of an intranasal norovirus viruslike particle (VLP) vaccine. The study was conducted in adults aged 18 to 50. They received two doses of either vaccine or placebo and were subsequently inoculated with Norwalk virus during an inpatient challenge with 10 times the infectious dose and monitored for infection and gastroenteritis symptoms for a minimum of 4 days. (No way I'd ever volunteer for this study)
The study included 98 patients with 90 completing both injections. A Norwalk virus–specific IgA seroresponse was found in 70% of vaccine recipients. This level of response is similar to my old Maryland colleague Samer El Kamary's 2010 JID paper that showed a 79% response rate. Vaccination significantly reduced the frequencies of Norwalk virus gastroenteritis (occurring in 69% of placebo and 37% of vaccine recipients, P=0.006) and Norwalk virus infection (82% of placebo and 61% of vaccine recipients, P=0.05). Not perfect, but still a great result.
Note: These data were also presented at earlier IDSA (2010) and ICAAC (2011) meetings.
Source: RL Atmar et al. NEJM Dec 8, 2011
Update: This news is pretty good too. (Massive drop in in-hospital deaths...in Canada)
I guess that since norovirus is a very common infection, the impact of the vaccine could be large, despite the fact that the effectiveness of the vaccine is <50%. I have always wanted to see a cost-benefit analysis of making anti-emetic drugs over-the-counter since many ER visits and some hospitalizations occur due to dehydration associated with norovirus. Since these drugs are relatively safe, I imagine the cost savings would be large.
ReplyDeleteI'm not sure we can judge effectiveness with this efficacy trial with 10x the infectious dose. I agree that a cost-analysis of anti-emetics and this vaccine would be very important.
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