Progress, but no magic bullets on the herpes front.

The drug acyclovir (brand name: Zovirax), already in limited use as an ointment and an intravenous solution in the treatment of genital herpes, has shown some promise in an experimental pill form.

Two recent studies have found the pills effective in protecting against recurrences of genital herpes, although they don't wipe out the virus which causes the disease. Scientists worry about long-term complications, such as increasing the herpes virus's resistance to the drug.

Genital herpes is usually spread by sexual intercourse. It is now the second most common sexually transmitted disease after gonorrhea, affecting an estimated 20 million Americans, with at least 300,000 new cases reported annually.

Genital herpes has no known cure, but acyclovir ointment has been approved for treatment of some patients during the first attack of the disease.

The latest data prompted the Harvard Medical School Health Letter to say of acyclovir: "All in all, the news for herpes sufferers falls short of 'breakthrough' status. But it qualifies as solid and encouraging progress."

Footnote: Herpes simplex virus type 1 of the mouth and gums can be transmitted to dental patients by a dentist or hygienist who fails to take adequate precautions, the Journal of the American Medical Association (Oct. 19, 1984) warns.

A dental hygienist with a herpes lesion on one finger infected 20 patients in four days, the journal reported. Researchers recommend that all dental personnel wear gloves when treating patients.