Final answer:
A safe and effective vaccine is available for hepatitis B, among sexually transmitted diseases. No vaccines are currently approved for HIV, syphilis, or chlamydia.
Step-by-step explanation:
A safe and effective vaccine is available for hepatitis B, which is a sexually transmitted disease (STD). Vaccines for other STDs, such as human papillomavirus (HPV), are available to prevent associated conditions like genital warts and cervical cancer. However, there is currently no approved vaccine for HIV or AIDS, and diseases like syphilis and chlamydia also lack vaccines. It is crucial to practice safe sexual behaviors and get regular health check-ups to prevent the transmission of STDs that cannot be vaccinated against.