- An agent, such as a virus (typically a retrovirus)
or a small piece of DNA called a plasmid,
that carries a modified or foreign gene.
When used in gene therapy, a vector
delivers the desired gene to a target cell. Once inside the host, the
vector can replicate and thus produce clones (exact copies) of the gene.
- An animal, usually an insect or a tick, that transmits parasitic microorganisms
– and therefore the diseases they cause – from person to
person or from infected animals to human beings. Mosquitoes, for example,
are vectors of malaria, filariasis,
and yellow fever.