Officials in Livingston County report 4 cases of whooping cough in the area in the last month. (wxxinews.org)
An outbreak of whooping cough in California could be the worst in 50 years, the state's Department of Public Health said last week. (newscientist.com)
Vaccines for whooping cough contain three to five protective antigens, the presence of which are critical to the vaccine's effectiveness. (sciencedaily.com)