Viral Vectors

Viral Vectors are a type of delivery system used in vaccine development to deliver genetic material from a pathogen into host cells, stimulating an immune response against the target pathogen. They are derived from viruses that have been genetically modified to carry and express antigens from the target pathogen without causing disease. Viral vectors work by infecting host cells and introducing the genetic material encoding specific antigens. Once inside the host cell, the viral vector hijacks the cell's machinery to produce the target antigens, which are then recognized by the immune system as foreign. This triggers an immune response, leading to the production of antibodies and memory cells that provide protection against future infections by the target pathogen.

There are several types of viral vectors commonly used in vaccine development, including adenoviruses, lentiviruses, retroviruses, and poxviruses. Each type of viral vector has its own advantages and limitations, depending on factors such as safety, immunogenicity, and scalability. Adenoviral vectors, for example, are efficient at delivering genetic material into host cells and inducing strong immune responses. They are particularly useful for generating rapid and robust immune responses against infectious diseases such as COVID-19, Ebola, and HIV. However, adenoviral vectors may be limited by pre-existing immunity in the population, which can reduce their effectiveness. Lentiviral vectors, derived from HIV, are another type of viral vector used in vaccine development. They have the advantage of being able to infect both dividing and non-dividing cells, making them suitable for targeting a wide range of cell types. Lentiviral vectors have been investigated for use in vaccines against HIV, cancer, and genetic disorders.