That's not what I've read.  I've read that after 12-16 weeks you are
generally immune to further infection.  For instance, if you have oral
herpes HSV-1 on your mouth, then you will not be at risk for
contracting from someone else on your genitals through oral sex.

From: http://www.herpes.com/hsv1-2.html
"A prior infection with oral HSV-1 lowers the risk of acquiring genital
HSV-1 even further. Studies show that genital HSV-1 infections almost
always occur in people who have no prior infection with HSV of either
type (Corey, Annals of Internal Medicine, 1983).

In the absence of prior oral infection, however, HSV-1 spreads easily
to the genital area, usually through oral sex. In some countries, such
as Japan and parts of Great Britain, genital HSV-1 is as common as
genital HSV- 2, or more common.

"Prevalence rates of genital HSV-1 differ based on the practice of oral
sex and on the percentage of people who are HSV-1 positive from
childhood," explains Anna Wald, MD researcher at the University of
Washington at Seattle.

Finally, the question of immunity and HSV types is complicated by an
additional issue. Some studies suggest that the ganglia themselves may
acquire some immunity to HSV after they are exposed to one viral type.

In the laboratory, infection of ganglia with more than one virus is
difficult, suggesting that it may be more difficult to acquire a second
HSV type in a location where you already have HSV. A prior genital
infection with HSV-1, for example, may give more protection against
genital HSV-2 than a prior oral infection with HSV-1.

What does all this mean on a practical level? Let's look at some
examples to find out. Say you have genital HSV-1 and your partner has
genital HSV-2. If you have unprotected sex, there is a small but real
risk that you will get HSV-2, resulting in more outbreaks and more
shedding. "We have documented cases where a person acquires HSV-2 after
a prior genital HSV- 1 infection," says Wald. "I don't think it happens
often, but it does happen."

On the other hand, it's very unlikely that your partner will get
genital HSV- 1 from you. "I've never seen a case of a person acquiring
HSV-1 on top of HSV-2," says Wald. "It's possible, but it would be
unusual."

What if your partner has genital HSV-2 and you perform oral sex on him
or her? Will you get HSV- 2 in the mouth? Given the widespread practice
of oral sex (some three-quarters of all adults practice it, according
to The Social Organization of Sexuality, 1994) and the prevalence of
genital HSV-2 infection, you might expect oral HSV-2 to be relatively
common. It's not.

According to one study, almost 100% of recognizable HSV-2 infection is
genital (Nahmias, Scandinavian Journal of Infectious Diseases
Supplement, 1990). One reason is that most adults are already infected
with HSV-1 orally, which provides some immunity against infection with
HSV 2. Another reason is that oral HSV-2 rarely reactivates, so even if
an infection does exist, no one knows.

So far we've been talking about transmission of HSV-1 or 2 from its
site of preference. What about transmission from another site? Say you
acquire genital HSV-1 through oral sex. Can you spread the virus to a
partner through genital sex?

The answer is yes, but probably not as easily as it was spread through
oral sex. The main reason is that the virus reactivates and sheds less
often outside its site of preference. Only about one quarter of people
with genital HSV- 1 shed virus at all in the absence of symptoms, while
55% of people with HSV-2 do (Wald, New England Journal of Medicine,
1995). "Shedding data appear to parallel recurrence data, meaning that
people who have a lot of recurrences also have a lot of shedding," says
Wald.

While HSV- 1 can be spread from genitals to genitals, "we think it is
spread more easily through oral sex because HSV-1 reactivates more
frequently in the oral area," says Wald. However, she warns,
"transmission of genital HSV-1 during asymptomatic shedding has been
documented." In other words, genital HSV-1 can be spread through
genital sex, even when there are no symptoms. "Good" Virus/ "Bad" Virus

If HSV infection is as easily transmitted from the mouth as from the
genitals, then why do people take steps to prevent genital but not oral
infection? Why don't we kiss through dental dams ?

"It's ironic, isn't it?" says Wald. "It's not about health, it's about
social acceptability."

Scientists can tell us all day that the main difference between the two
viral types is simply their site of preference-whether they typically
occur above the waist or below. But the unspoken attitudes of our
society send a different message. That's just the problem, social
attitudes whisper. Below the waist is bad.

"People think of oral herpes as the "good" herpes and genital herpes as
the "bad" kind," says Glover of the National Herpes Hotline. "It's
partly that they don't understand the similarities between HSV-1 and 2.
But it's also that good and bad is how our culture views sex and our
bodies."

The inescapable fact is that HSV-1 is usually spread through contact
with infected lips, while HSV-2 usually spread through contact with
infected genitals. From a social point of view, the problem is not the
disease; it's how you got it.

Whether we like it or not, the social prejudice against genital herpes,
no matter which virus causes it, is a reality. "People have more
trouble explaining to a new partner that they have genital herpes, even
if it's HSV- 1, than if they have a cold sore," says Glover. "Just
saying the word "genital" is like an anvil that pulls the sentence
down".

Is this topic making you crazy? For people who have trouble dealing
with social attitudes toward genital herpes, the blatant double
standard society applies to oral herpes can be frustrating, to say the
least.

"Talk to a wise friend," suggests Rebecca, a health communication
specialist on the National Herpes Hotline. "Join a support group. Find
Someone you respect and exchange ideas them. It's always reassuring to
see that not everyone lives inside the walls our society builds around
sexual issues and realities. "

It's also worth hoping that new research on the similarities between
HSV-1 and 2, as well as increased public education about genital
herpes, can help lower the level of misunderstanding about both types
of the virus. Today, the greatest difference between HSV- 1 and 2
appears to be the way we think about them. Tomorrow, that may
change...."

Actually, it can infect the fingers of doctors/nurses who have
examined patients without wearing gloves.  It will also
infect the skin of wrestlers, where it has been called
"Herpes Gladiatoris".  

Steve