Condoms are an effective method of preventing sexually transmitted infections (STIs) and sexually transmitted diseases (STDs) when used correctly. However, they are not 100% effective in preventing all STIs and STDs. Here are some STIs and STDs that condoms do not always prevent:

• Herpes
• Human papillomavirus (HPV)
• Syphilis
• Molluscum contagiosum
• Trichomoniasis

These infections can be spread through skin-to-skin contact, which may or may not infect areas covered by a condom. It is important to note that condoms are still the best method for protecting against STDs, including HIV/AIDS. To minimize the risk of contracting an STI or STD, it is recommended to practice safe sex, get tested regularly, and know your partners STD and health history.