Enhanced Adenovirus Vaccine Safety Surveillance in Military Setting, United States.

The US Coast Guard Academy began adenovirus vaccination of incoming cadets in 2022. Of 294 vaccine recipients, 15%-20% had mild respiratory or systemic symptoms within 10 days postvaccination but no serious adverse events after 90 days. Our findings support the continued use of adenovirus vaccines in congregate military settings.

Outbreak of Acute Respiratory Illness Associated With Human Adenovirus Type 4 at the United States Coast Guard Academy, 2019.

BACKGROUND: Although a human adenovirus (HAdV) vaccine is available for military use, officers-in-training are not routinely vaccinated. We describe an HAdV-associated respiratory outbreak among unvaccinated cadets at the US Coast Guard Academy and its impact on cadet training. METHODS: We defined a case as a cadet with new onset cough or sore throat during August 1-October 4, 2019. We reviewed medical records and distributed a questionnaire to identify cases and to estimate impact on cadet training. We performed real-time polymerase chain reaction testing on patient and environmental samples and whole genome sequencing on a subset of positive patient samples. RESULTS: Among the 1072 cadets, 378 (35%) cases were identified by medical records (n = 230) or additionally by the questionnaire (n = 148). Of the 230 cases identified from medical records, 138 (60%) were male and 226 (98%) had no underlying conditions. From questionnaire responses, 113 of 228 (50%) cases reported duty restrictions. Of cases with respiratory specimens, 36 of 50 (72%) were HAdV positive; all 14 sequenced specimens were HAdV-4a1. Sixteen (89%) of 18 environmental specimens from the cadet dormitory were HAdV-positive. CONCLUSIONS: The HAdV-4-associated outbreak infected a substantial number of cadets and significantly impacted cadet training. Routine vaccination could prevent HAdV respiratory outbreaks in this population.