Human immunodeficiency virus (HIV) is a virus that attacks the immune system, which is responsible for fighting off infections and diseases. HIV is transmitted through contact with infected bodily fluids, such as blood, semen, vaginal fluids, and breast milk. It can be transmitted through sexual contact, sharing needles, mother-to-child transmission during pregnancy, childbirth, or breastfeeding, and other modes of transmission.
HIV attacks and destroys a specific type of immune cell called CD4 T-cells, which are important for protecting the body against infections. As the virus destroys more and more CD4 T-cells, the immune system becomes weakened, making it difficult for the body to fight off infections and diseases. Without treatment, HIV can progress to acquired immunodeficiency syndrome (AIDS), a condition in which the immune system is severely damaged and opportunistic infections and cancers can occur.
Despite advances in HIV treatment, including antiretroviral therapy (ART) that can suppress the virus and prevent progression to AIDS, HIV remains a major global health challenge. According to the World Health Organization, approximately 38 million people worldwide were living with HIV at the end of 2019. While efforts to prevent new HIV infections and provide treatment and care for those living with HIV have made progress, continued research, and innovation are needed to develop effective prevention methods, treatments, and ultimately, a cure for HIV.
A clinical trial tested a vaccine that uses a combination of two different types of vaccines. The first type is called a DNA vaccine, which is a small piece of genetic material that is given to the body to train the immune system to fight against HIV. The second type is called a viral vector vaccine, which uses a harmless virus to deliver the HIV protein to the body to stimulate an immune response.