# Lackland Air Force Base flu outbreak > Live situation record from CLSTR: https://clstr.news/situations/lackland-air-force-base-flu-outbreak > Updated: 2026-06-30T22:21:50.000Z. Sources: 34. Developments: 6. The influenza outbreak that began in mid‑June 2026 at Joint Base San Antonio‑Lackland has now sickened more than 280 service members, four of whom have been hospitalized, and has claimed the life of a 25‑year‑old trainee, Keon McDaniel, who died on June 16. The death remains under investigation, and officials say there is no clear evidence linking it to influenza or to the April decision by Defense Secretary Pete Hegseth to make flu vaccinations voluntary. After the April repeal, only about 40 % of new recruits received the flu shot. In response to the rapidly spreading illness, the Army, Navy and Air Force reinstated a mandatory flu‑shot requirement for new recruits, initially approved for basic‑training on June 11 and expanded on June 24 to cover all branches, with limited exemptions for agencies such as the NSA and the Defense Health Agency. The Pentagon has now ordered boot camps across all services to require the vaccine again, citing the outbreak’s speed in close‑quarters training environments. U.S. Representatives Joaquin Castro, Gil Cisneros and Chrissy Houlahan have introduced an amendment to the National Defense Authorization Act to make flu vaccination mandatory for all service members, arguing that the earlier voluntary policy jeopardized military readiness. Antiviral medication, including Tamiflu, continues to be administered to symptomatic trainees. Pentagon spokesperson Sean Parnell defends the expanded mandate as essential for readiness, while some medical experts and members of Congress criticize earlier voluntary‑vaccination policies and question media narratives that directly tie the outbreak to the policy change. The situation underscores ongoing tensions between medical‑autonomy reforms and public‑health measures in densely populated military training environments. ## Timeline ### 2026-06-30: Lackland Air Force Base flu outbreak prompts push to reinstate mandatory vaccine for US troops A flu outbreak at Lackland Air Force Base, linked to the 2023 repeal of the military vaccine mandate, has sickened 284 troops, hospitalized four and caused one death, prompting Congress to push a bill to reinst 2 sources. https://clstr.news/cluster/lackland-air-force-base-flu-outbreak-prompts-push-to-reinstate-mandatory-vaccine-for-us-troops ### 2026-06-25: U.S. Military Reinstates Flu Vaccine Mandate After Texas Outbreak U.S. military re‑imposes flu vaccine requirements after a Texas base outbreak sickened 222 recruits, hospitalized four and caused one death, though a link to the illness is unconfirmed. 2 sources. https://clstr.news/cluster/us-military-reinstates-flu-vaccine-requirement-after-texas-base-outbreak ### 2026-06-24: US Military Restores Flu Vaccine Mandate After Texas Base Outbreak After a flu outbreak infected up to 222 trainees and caused a death at Lackland Air Force Base, the US Pentagon reinstated mandatory flu vaccinations for all basic‑training recruits. 2 sources. https://clstr.news/cluster/us-military-restores-flu-vaccine-mandate-after-texas-base-outbreak ### 2026-06-24: Pentagon reinstates flu vaccine mandate for recruits after Lackland outbreak After Defense Secretary Pete Hegseth made flu shots optional, a COVID‑free influenza outbreak at Lackland Air Force Base sickened ~275 recruits, prompting the Pentagon to reinstate mandatory flu vaccinations in 19 sources. https://clstr.news/cluster/us-military-reinstates-flu-shots-for-some-recruits-after-texas-outbreak ### 2026-06-22: U.S. Air Force Flu Outbreak at Lackland Base Triggers Mandatory Vaccine Requirement A flu outbreak at Lackland Air Force Base sickened 222 trainees, killed one, and led the Air Force to reinstate mandatory flu shots for recruits, amid calls for a full investigation. 2 sources. https://clstr.news/cluster/us-air-force-flu-outbreak-at-lackland-base-triggers-mandatory-vaccine-requirement ### 2026-06-18: Flu outbreak at Lackland Air Force Base sickens about 160 trainees Around 160 Air Force trainees at Lackland Base in Texas fell ill with flu weeks after the vaccine became voluntary; the base re‑imposed mandatory shots and a trainee’s death is under review. 8 sources. https://clstr.news/cluster/flu-outbreak-hits-lackland-air-force-base-after-vaccine-mandate-ends --- Cite as: Lackland Air Force Base flu outbreak. CLSTR, https://clstr.news/situations/lackland-air-force-base-flu-outbreak