Vektorvacciner

Vektorvacciner are vaccines that use a harmless virus or other vector to deliver genetic material encoding an antigen from a pathogen into the body's cells. The vector is engineered to be replication-deficient or otherwise attenuated, so it cannot cause disease, but can introduce the antigen gene to elicit an immune response. Once inside, host cells express the antigen and present it to the immune system, stimulating both antibody production and T cell responses.

Most widely used platforms are viral vectors, particularly adenoviruses (such as Ad5, Ad26, and chimpanzee-derived ChAd), though other vectors like vesicular stomatitis virus (VSV) and vaccinia virus have been explored. Some vaccines use replication-deficient vectors for safety, while a few use replication-competent vectors with safety controls. Adenoviral vectors are among the most established in human vaccines.

Examples include several COVID-19 vaccines, such as ChAdOx1-S (AstraZeneca) and Ad26.COV2.S (Johnson & Johnson), as well as Sputnik V (which uses two different adenovirus vectors). The rVSV-ZEBOV vaccine for Ebola is another well-known vector vaccine. Numerous vector vaccines are in development for infectious diseases and, in research, for cancer and other conditions.

Advantages of vektorvacciner include the ability to induce robust humoral and cellular immunity and potential for single-dose regimens with relatively stable production. Limitations include pre-existing immunity to common vectors, manufacturing complexity, and rare safety concerns such as immune-mediated adverse events associated with some viral vectors. Ongoing regulatory review and pharmacovigilance accompany their development and deployment.