The non-specific effects (NSEs) of vaccines have been discussed for their potential long-term beneficial effects beyond direct protection against a specific pathogen. Cold-adapted, live attenuated influenza vaccine (CAIV) induces local innate immune responses that provide a broad range of antiviral immunity. Herein, we examined whether X-31ca, a donor virus for CAIVs, provides non-specific cross-protection against respiratory syncytial virus (RSV). The degree of RSV replication was significantly reduced when X-31ca was administered before RSV infection without any RSV-specific antibody responses. The vaccination induced an immediate release of cytokines and infiltration of leukocytes into the respiratory tract, moderating the immune perturbation caused by RSV infection. The potency of protection against RSV challenge was significantly reduced in TLR3-/- TLR7-/- mice, confirming that the TLR3/7 signaling pathways are necessary for the observed immediate and short-term protection. The results suggest that CAIVs provide short-term, non-specific protection against genetically unrelated respiratory pathogens. The additional benefits of CAIVs in mitigating acute respiratory infections for which vaccines are not yet available need to be assessed in future studies.

We compared the fate of cold‐stressed (CS) or tetracycline‐resistant (TR) Vibrio parahaemolyticus, Vibrio vulnificus, and Vibrio cholerae in precooked shrimp during frozen storage. The recovery ability of viable but nonculturable (VBNC) Vibrio cells was compared at 25°C. Each suspension of nonstressed (NS), CS, or TR Vibrio cells inoculated into cooked shrimps were subjected to frozen storage at −20°C or three freeze–thaw cycles. CS and TR cells were more rapidly converted to VBNC state than NS cells. Most of VBNC Vibrio cells were observed as viable cells after frozen storage. Although there were differences in the recovery extent of cells depending on the types of stress and strain, VBNC cells were resuscitated at 25°C. The most resistant to tetracycline and the lowest injury rate were observed in V. cholerae cells during frozen storage.