Passive immunization and West Nile Virus
In 1999, officials reported the first cases of West Nile Virus (WNV) in North America in eight New York City patients. Baxter Healthcare scientist Thomas Kreil realized that sera from infected patients might protect others by passive immunization. The map above, adapted from the CDC, shows how quickly the virus spread west over the next four years. Human cases, usually asymptomatic, followed reports of animal infections. Serum pools collected from areas with high infection rates would have more anti-WNV antibodies. Read more about Kreil's experiments to test his hypothesis in this month's issue.