Ann: HSV-2 Phase II Initial Results, page-69

Not many people understand how the trial is run and how HSV works. When looking at outbreaks (OBs) you are comparing it to the pre-vaccination time period which is 45 days. Outbreaks are not an exact science. They basically come when they come (although there are factors that can increase the likelihood but we won't get into them here). Even the placebo groups can experience a decrease in outbreaks just by chance. In other words they just didn't have as many during the post vaccination assessment as they did during the prevaccination baseline. Overall you are looking for a statistically significant reduction of OBs between the placebo and non-placebo groups. It is worth noting the average person gets 4-6 OBs per year.

By far the more important determinant that is assessed and which determine the success of the vaccine to a greater extent is the viral shedding rate. Individuals who have HSV-2 shed virus even when they do not have an OB and as a result can transmit the virus when they do not have an OB. This is the factor and gives HSV-2 it's social stigma and what psychologically impacts individuals who have it. In other words you can potentially pass on the virus anytime during physical skin-to-skin contact.

Both recent trials of Agenus and Genocea reported a significant reduction in viral shedding which (in my opinion) was far from optimal. Genocea is still running with their vaccine (GEN003) and Agenus appears to have shelved theirs.

That being said the 90% reduction in OBs is by far the best result I have heard of to date but will not hold much weight until the shedding results are in.

I hope this helps.