A candidate vaccine virus (CVV) is a virus that has been developed in a lab for the purposes of being used by vaccine manufacturers to develop and then produce a vaccine against that virus. One type of CVV that has been in development for a number of years is an influenza virus to prepare for the possibility of highly pathogenic avian influenza virus that mutates enough that it can “jump” (spillover) into humans in a configuration that can then be transmitted from one human to another. The CDC routinely develops CVVs for new bird flu viruses that have the potential to spark a pandemic. The final step of after developing HPAI CVVs is to share them with WHO Collaborating Centers.
