Some commercial sex workers in Kenya who apparently are immune to HIV might be carrying a gene that protects them from contracting the virus, according to a study presented last week at the XVI International AIDS Conference in Toronto, the EastAfrican reports. The study, conducted by researchers from the University of Manitoba in Canada, was based on follow-up studies of more than 850 sex workers in Nairobi, Kenya. Over three years, most of the women contracted HIV, but at least 130 did not test positive for the virus despite each having unprotected sex with more than 500 men. According to data from the University of Nairobi, some of the sex workers have up to 30 clients per day. The study finds that the sex workers might be protected from contracting HIV by a gene known as human leukocyte that enables the immune system to recognize HIV and other similar viruses. The findings support the theory that a significant number of people are naturally immune to HIV, according to the EastAfrican (Kimani, EastAfrican, 8/22).