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The past decades influenza B lineages Victoria and Yamagata cocirculated. Our aim was to estimate the distribution of the two lineages circulating in Greece and any possible mismatching with vaccine influenza B strains. We studied 490 laboratory-confirmed influenza B nonsevere acute respiratory infection (non-SARI) cases diagnosed in the two National Influenza Reference Laboratories by reverse transcriptase polymerase chain reaction from July 1, 2005 to June 30, 2015 and 100 influenza B SARI cases diagnosed from July 1, 2011 to June 30, 2015. Median matching between the circulating influenza B lineages and the vaccine influenza B strains was 19.2% (range: 0–100%) for non-SARI cases during 2005–2015 and 67.6% (range: 41.2–94.1%) for SARI cases during 2011–2015. In two influenza seasons (2005–2006 and 2006–2007), complete lineage mismatch between influenza B non-SARI cases and influenza B vaccine strains was found. We estimated that 5, 12, or 16 laboratory-confirmed SARI cases could have been prevented by quadrivalent influenza inactivated vaccine (QIV) during the 2011–2012 season and 1, 2, or 3 SARI cases during the 2014–2015 season, with a vaccination coverage rate of 70% and a vaccine effectiveness of 20%, 50%, or 70%, respectively. Significant cocirculation of Victoria and Yamagata B strains and mismatching with vaccine influenza B strains were found during 2005–2015 in Greece. The wide use of a QIV instead of a TIV will confer additional immunity and therefore protection against influenza B, and it is expected to prevent several SARI cases annually. Our findings strongly support the recommendations for using QIV. [ABSTRACT FROM AUTHOR]

The development of an effective preventative hepatitis C virus (HCV) vaccine will reside, in part, in its ability to elicit neutralizing antibodies (NAbs). We previously reported a genotype 1a HCV virus like particle (VLP) vaccine that produced HCV specific NAb and T cell responses that were substantially enhanced by Toll-like receptor 2 (TLR2) agonists. We have now produced a quadrivalent genotype 1a/1b/2a/3a HCV VLP vaccine and tested the ability of two TLR2 agonists, R4Pam2Cys and E8Pam2Cys, to stimulate the production of NAb. We now show that our vaccine with R4Pam2Cys or E8Pam2Cys produces strong antibody and NAb responses in vaccinated mice after just two doses. Total antibody titers were higher in mice inoculated with vaccine plus E8Pam2Cys compared to HCV VLPs alone. However, the TLR2 agonists did not result in stronger NAb responses compared to vaccine without adjuvant. Such a vaccine could provide a substantial addition to the overall goal to eliminate HCV. [ABSTRACT FROM AUTHOR]