What are viral vectors?
Viral vectors are tools designed to deliver genetic material into cells. Viruses have evolved to develop specialized mechanisms which transport their genomes inside the cells they infect. Modified viruses are used as viral vectors (or ‘carriers’) in gene therapy, protecting the new gene from degradation while delivering it to the “gene cassette” in target cells. Viral vectors effectively coerce target cells to accept and separate the new gene from the virus particle and transport it to the cell nucleus, for example. The target cells begin using the new gene to perform its function. Most of the essential genes in viral vectors are missing due to genetic engineering which means viral vectors are often grown in culture with special cells that provide the missing viral proteins to successfully package the therapeutic gene(s) into virus particles.
There are several types of viral vectors that can be used to deliver nucleic acids into the genetic makeup of cells including retrovirus, lentivirus, adenovirus, adeno-associated virus and herpes simplex virus–each with its own advantages and disadvantages for specific applications.