Yes, he can. Asymptomatic shedding (no visible signs of an outbreak) even on an antiviral drug occurs frequently. Antiviral drugs taken alone (without a condom) reduce the incidence of transferring herpes to an unifected partner by 49% according to this article: http://consults.blogs.nytimes.com/2010/06/18/giving-your-partner-herpes/. There is no such a thing as 100% protection from herpes.
Unfortunately, herpes is with you for life. If people with the virus would recognize they can no longer have sexual relations with unifected partners without disclosing it; making sure their partners understand the risk and take all of the necessary precautions to prevent it; so many people would not have to suffer from this virus. Many of us have terrible outbreaks years later as our immune systems breakdown. With me, I decided early on not to have sexual relations with unifected partners and have been alone since. There are so many other STDs that I am more proned to as a result of being imfected with the herpes virus and I don't want to deteriorate my health any more than I have already done so.
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