Quadrivalent influenza vaccine: a new opportunity to reduce the influenza burden.

Influenza illness is caused by influenza A and influenza B strains. Although influenza A viruses are perceived to carry greater risk because they account for the majority of influenza cases in most seasons and have been responsible for influenza pandemics, influenza B viruses also impose a substantial public health burden, particularly among children and at-risk subjects. Furthermore, since the 2001-2002 influenza season, both influenza B lineages, B/Victoria-like viruses and B/Yamagata-like viruses have co-circulated in Europe. The conventional trivalent influenza vaccines have shown a limited ability to induce effective protection when major or minor mismatches between the influenza B vaccine component and circulating strains occur. For this reason, the inclusion of a second B strain in influenza vaccines may help to overcome the well-known difficulties of predicting the circulating B lineage and choosing the influenza B vaccine component. Two quadrivalent influenza vaccines, a live-attenuated quadrivalent influenza vaccine (Q/LAIV) and a split inactivated quadrivalent influenza vaccine (I/QIV), were first licensed in the US in 2012. Since their introduction, models simulating the inclusion of QIV in influenza immunization programs have demonstrated the substantial health benefits, in terms of reducing the number of influenza cases, their complications and mortality. In the near future, evaluations from simulation models should be confirmed by effectiveness studies in the field, and more costeffectiveness analyses should be conducted in order to verify the expected benefits.

Seasonal variation of kaurenoic acid, a hypoglycemic diterpene present in Wedelia paludosa (Acmela brasiliensis) (Asteraceae).

We evaluated the variation of the concentration of kaurenoic acid (1), which is a bioactive diterpene, in leaves, flowers, stems and roots from Wedelia paludosa (Acmela brasiliensis) for different seasons using the HRGC/FID method. The results indicated that the concentration of 1 is higher in the roots and stems during the autumn. The pharmacological results suggested that kaurenoic acid is responsible, at least in part, for the hypoglycemic potential detected in this plant.