From here, however, the question of transmissibility gets more complicated. Acquisition of one type is more difficult-though certainly possible-if you already have the other type. This is because either type, contracted orally or genitally, causes the body to produce antibodies, some of which are active against both HSV-1 and 2. This acquired immune response gives some limited protection if the body encounters a second type. When a person with a prior HSV infection does contract the second type, the first episode tends to be less severe than when no prior antibodies are present.
According to the American College of Obstetricians and Gynecologists, “women who have their first genital herpes infection in late pregnancy (whether symptomatic or asymptomatic) and who give birth vaginally have a high risk (30–50%) of transmitting the virus to their infants. Similarly, nonprimary first-episode HSV infection occurring late in pregnancy also has a high risk of vertical transmission. The risk of transmission during a vaginal delivery is much lower with recurrent infection (less than 2–5%). Currently, most newborns infected with HSV are delivered to women who have asymptomatic or unrecognized infections. Genital herpes infection is classified as primary when it occurs in a woman with no evidence of prior HSV infection (ie, seronegative for both HSV-1 and HSV-2), as a nonprimary first episode when it occurs in a woman with a history of heterologous infection (eg, first HSV-2 infection in a woman with prior HSV-1 infection or vice versa), and as recurrent when it occurs in a woman with clinical or serologic evidence of prior genital herpes (of the same serotype).”
Canker sores are a common complaint, and are small ulcers on the inside of the mouth. Canker sores aren't contagious (as opposed to cold sores), and typically last for 10-14 days usually healing without scarring. A variety of things cause canker sores, for example, medications (aspirin, beta blockers, NSAIDs, high blood pressure medication, and antibiotics); injury to the mouth from dental work, braces, or sports accidents; acidic foods; allergies; and diseases or conditions like celiac disease, Crohn's disease, and lupus.