A nursing home reports low influenza vaccine uptake among staff and residents followed by an outbreak. Which immediate actions best reduce further transmission and protect unvaccinated and immunocompromised residents?

• A. Only give boosters to residents who previously declined vaccination while continuing normal staffing and visitation policies because incremental vaccination of residents alone will immediately restore herd immunity within 24 hours.
• B. Implement urgent targeted vaccination of staff and residents, use antiviral prophylaxis for exposed high-risk residents, restrict nonessential visitors, and reinforce mask use and cohorting until transmission is controlled.
• C. Do nothing beyond informing families because outbreaks in congregate settings always resolve spontaneously without interventions and because additional measures would infringe on residents' autonomy.
• D. Close the facility permanently and discharge all residents to the community immediately because institutional settings cannot be salvaged once any outbreak begins, which is the only ethical option.

Answer: (B)