Quarantine is more effective at initially preventing disease spread than vaccination. Health and Medicine Division 20

At the start of a contagious disease outbreak, there may be a shortage or absence of countermeasures such as drugs and vaccines. Similarly, there may be regions in the country where the stockpile of drugs and vaccines is limited or the delivery of such supplies will take time because of remoteness. In these circumstances, NPIs, including quarantine, may be the only measures available to combat the outbreak. Modeling studies suggest that quarantine is more effective when implemented earlier in an outbreak, and even a relatively ineffective quarantine may help blunt or slow the epidemic curve, allowing more time for resources to arrive in the area. (Evidence source: synthesis of modeling studies, qualitative evidence synthesis, and case report evidence synthesis. Refer to Section 10, “Other Implementation Considerations,” in Appendix B4 for additional detail.)