Can You Develop Smallpox Through Sex?

In June 2012, a man in San Diego was infected with the vaccinia virus, which is the virus found in the smallpox vaccine, after being in sexual contact with someone who’d recently been vaccinated. Not only was the virus transferred between bodies but the man also passed the virus on to a unvaccinated person during sexual activity – this is known by researchers as tertiary transmission. The vaccine used for smallpox contains the live vaccinia virus which doesn’t contain the disease itself but is very similar.

The vaccine contains a live virus which means that it can cause symptoms in vaccinated people, as well as spreading to others if you come into contact with them. One can become infected with smallpox through touching the vaccination site on someone who has been vaccinated, or through touching clothing which has been contaminated with the virus. The symptoms include rashes, a fever or head and bodily aches. Since 2002, there have been reports of 115 cases of the vaccinia virus being transmitted between vaccinated and unvaccinated people. Most of these cases have been transmitted through sexual contact or intimate contact, such as between mother and child. Gyms have even been noted as being prime locations for transmissions to occur. The first case of sexual transmission happened when the infected man had sex with a recently vaccinated man who didn’t keep the vaccination area covered properly. The man who became infected then developed a rash in the anal area and on his lip, experiencing a fever and fatigue all the while. This man then later had sex with another man, who also caught the disease.

The study shows that the vaccinia virus has the potential to spread far beyond the immediate contacts of the person who has been vaccinated. Researchers stress that there needs to be more importance placed on covering the vaccination site, which is advised for everyone who receives the vaccination.