Current inﬂuenza vaccines induce strain-speciﬁc immunity to the highly variable hemagglutinin (HA) protein. It is therefore a high priority to develop vaccines that induce broadly cross-protective immunity to different strains of inﬂuenza. Since inﬂuenza A M2 proteins are highly conserved among different strains, ﬁve tandem repeats of the extracellular peptide of M2 in a membrane-anchored form on virus- like particles (VLPs) have been suggested to be a promising candidate for universal inﬂuenza vaccine. In this study, ferrets were intramuscularly immunized with 2009 H1N1 split HA vaccine (“Split”) alone, inﬂuenza split vaccine supplemented with M2e5x VLP (“Split+M2e5x”), M2e5x VLP alone (“M2e5x”), or mock immunized. Vaccine efﬁcacy was measured serologically and by protection against a sero- logically distinct viral challenge. Ferrets immunized with Split+M2e5x induced HA strain speciﬁc and conserved M2e immunity. Supplementation of M2e5x VLP to split vaccination signiﬁcantly increased the immunogenicity of split vaccine compared to split alone. The Split+M2e5x ferret group showed evidence of cross-reactive protection, including faster recovery from weight loss, and reduced inﬂammation, as inferred from changes in peripheral leukocyte subsets, compared to mock-immunized animals. In addi- tion, ferrets immunized with Split+M2e5x shed lower viral nasal-wash titers than the other groups. Ferrets immunized with M2e5x alone also show some protective effects, while those immunized with split vaccine alone induced no protective effects compared to mock-immunized ferrets. These stud- ies suggest that supplementation of split vaccine with M2e5x-VLP may provide broader and improved cross-protection than split vaccine alone.
Music, N., Reber, A. J., Kim, M.-C., York, I. A., & Kang, S.-M. (2016). Supplementation of H1N1pdm09 split vaccine with heterologous tandem repeat M2e5x virus-like particles confers improved cross-protection in ferrets. Vaccine, 34(4), 466–473. http://dx.doi.org/10.1016/j.vaccine.2015.12.023
Creative Commons License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License.