Eight to ten-week-old C57BL/6 wildtype and IL-1 receptor type 1 deficient (IL-1R2/2, strain name B6.129S7-Il1r1 tm1Imx/J ) mice were obtained from Jackson Laboratories. Caspase12/2 on the C57BL/6 background were generously provided by Dr. Fayyaz Sutterwala and Dr. Richard Flavell. ASC2/2 and Nlrp32/2 mice on the C57BL/6 background were generously provided from Genentech Inc. (San Francisco, CA). Mice obtained commercially were housed for at least 1 week before experiments were initiated. Mice were housed in microisolator cages in a biosafety level 2-equipped animal facility. Viral stocks were diluted to appropriate titers in serum-free DMEM. For intramuscular immunization (i.m.), mice were injected with the indicated amount of virus(es) in 50 ml total volume. For intranasal (i.n.) vaccination, mice were lightly anesthetized with isoflurane using a vaporizer and administered the indicated amount of virus in 30 ml total volume. The Institutional Animal Care and Use Committee of Duke University approved all animal experiments.