Pertussis Cases Rise in Los Angeles and at USC
Students and residents should monitor for symptoms as vaccine immunity wanes five to six years after the final dose.
Updated on Oct. 22, 2026 in Asthma
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Pertussis, also known as whooping cough, is seeing an increase in reported cases across Los Angeles County and at the University of Southern California, where six instances have been confirmed among students. The highly contagious respiratory infection has triggered increased monitoring and surveillance measures for the local campus population.
Why it matters
The rise in cases is attributed to waning vaccine immunity, as protection typically begins to decline five to six years after the final dose is administered. Understanding this vulnerability is essential for students and residents with pre-existing conditions like asthma, who face a higher risk for severe infection.
USC Student Health identified 6 confirmed cases of Bordetella pertussis via its campus-wide wastewater surveillance program spanning 10 residential buildings. While clinical data remains limited to current diagnostic testing, the long-term effectiveness of vaccine immunity is still under investigation.
The players
USC Student Health
The primary healthcare provider for university students that manages clinical services and infection surveillance programs.
The details
Pertussis is a bacterial infection that spreads through airborne droplets released when an infected person coughs or sneezes. Once the bacteria enter the respiratory system, the infection can trigger severe, uncontrolled coughing fits that persist for 10 weeks or longer. Individuals with immunocompromising conditions or asthma are at an elevated risk of experiencing severe complications compared to the general population.
Timeline
Fall 2026: Increasing reports of pertussis at USC.
5 to 6 years: Typical duration of pertussis vaccine immunity.
Age 11 or 12: Standard age for receiving initial pertussis vaccination.
Health Landscape
Public health surveillance is increasingly shifting toward wastewater monitoring to provide early warning of respiratory pathogens on dense campuses. This approach complements traditional clinical reporting to help manage the cyclical nature of waning immunity against established childhood diseases.
Students and residents with asthma should monitor their respiratory health for symptoms like persistent coughing, congestion, or fever and contact a physician if symptoms emerge. Those who received their last vaccination more than five years ago should consult their doctor about current immunity status.
The takeaway
Pertussis is highly contagious, with roughly 80% of those lacking immunity contracting the bacteria upon exposure. If you or a family member develop a severe, prolonged cough, reach out to your primary care provider to discuss testing and appropriate clinical evaluation.
Further reading
For more information on managing respiratory triggers, visit the Asthma resources page.
Source note: This article includes information reported by Daily Trojan.
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During a local outbreak of a contagious disease, do you proactively check your vaccination status?
