Or, if he uses only a condom during intercourse, what is the reduction of transmission? 

Condoms reduce transmission from males to females by 96% when used with every intercourse - VERY effective.  I am not seeing the difference between your first question and your second one?  Can you clarify please?  It looks to me like in both questions you as asking about the reduction in transmission if he uses a condom.

Terri

Thanking  you again,  Ms. Warren.  Your advice is so appreciated.

Our data, which is acquired from looking at what we call discordant couples (one is infected with HSV 2 and one is not), indicates about a 10% transmission rate per year with no interventions at all, having sex about twice per week, avoiding sex with outbreaks of course.  It should be noted that these couples that were studied are not brand new partner - they've been having sex for a while before they entered the studies and transmission is most common in the first three months of a new relationship, so these number might not apply specifically to your situation, but it is an estimate.

Antiviral medication reduces transmission by about 50% and for most people have few side effects.

Terri

That is only about HSV 2, correct, but remember that these couples are what we term "survivors", that is, they haven't acquired HSV 2 during the course of their sexual relationship, so far.

Terri