Petty Officer 3rd Class Michelle Tilley gives a patient an immunization shot. U.S. Navy Petty Officer 3rd Class Michelle Tilley (left) gives a patient an immunization shot at the Arima Health Facility in Arima, Trinidad and Tobago, on Sept. 17, 2007. Tilley is assigned to the hospital ship USNS Comfort (T-AH 20). The Military Sealift Command ship is on a four-month humanitarian deployment to Latin America and the Caribbean to provide medical treatment to patients from a dozen countries. SHARE: Download: Full Size (0.03 MB) Credit: VIRIN: 790862-G-GRE23-910.jpg Photo Gallery