If you have herpes, are you immune to a second infection from someone else?
A study done in 1980 in Atlanta, Georgia, showed that genital herpes can recur
with more than one strain of the virus. People with one strain of herpes can
get another. Since immunity is important, it is generally thought that getting
herpes a second time is substantially more difficult than getting it the first
time. Transmission of type 2 genital herpes to a person who has Western blot
antibody against type 2 herpes is rare. Studies have shown that a person with
genital herpes can catch a new case of genital herpes, but other studies have
shown that this happens only rarely. In most cases, if a person with genital
herpes catches genital herpes while with a partner, they are catching it from
themselves -having a recurrence. Type-specific antibody against your own strain
of virus makes it very difficult to catch a second infection of the same strain
from a different person.
Telling one strain of herpes from another
It takes painstaking effort to tell one herpes strain from another, but it
can be done by obtaining a "DNA fingerprint." The test is not one a family doctor
or even a specialist can perform. Rarely, 2 strains on separate recurrences
in the same person and dual infections of 2 strains at the same time have
been observed. However, second infections with new strains are considered to
be extremely rare.
Studies that have sought different strains from a single person with genital
herpes have had a very difficult time finding them in most people. Yet statistics
suggest that people with genital herpes commonly come in contact with herpes
from more than one partner. There must be a very strong immunity to second infection,
although it is not yet defined scientifically.
How will you know if you have a second infection?
Although incomplete, immunity to type 1 herpes affords a very high degree of
protection against infection with type 2 herpes. This protection makes type
2 somewhat more difficult to get. Antibody to type 1 herpes, however, does not
fully protect against type 2. Many people who get type 2 herpes do so despite
having this type 1 partial protection. People with type 1 who do get type 2
will, by definition, not experience a true primary infection.
The first episode will likely be less severe than for people who have no preexisting
immunity to type 1 or type 2. It may be that people with type 1 immunity are
somewhat predisposed to acquire type 2 genital herpes asymptomatically, should
they come in contact with type 2 herpes and acquire infection from a partner.
Since their bodies are already fully equipped to fight off the infection effectively,
people with type 1 herpes are probably more likely not to notice infection with
type 2. Type 1 herpes is just as likely as type 2 herpes, however, to be acquired
without any evident symptoms - so, while a history of recurrent oral cold sores
is strongly suggestive of type 1 herpes simplex, the absence of such a history
provides absolutely no evidence that a person does not have latent herpes simplex
virus type 1. Only type-specific antibody tests like the Western blot are able
to do that.