Schlumberger Faculty for the Future, CRDF Global (31141), the Swedish International Development Cooperation Agency, the County Council of Västerbotten, and the Faculty of Medicine, Umeå University.

Introduction: Two species of Aedes (Ae.) mosquitoes (Ae. aegypti and Ae. albopictus) are primary vectors for emerging arboviruses that are a significant threat to public health and economic burden worldwide. Distribution of these vectors and the associated arboviruses, such as dengue virus, chikungunya virus, yellow fever virus, and Zika virus, was for a long time restricted by geographical, ecological, and biological factors. Presently, arbovirus emergence and dispersion are more rapid and geographically widespread, largely due to expansion of the range for these two mosquitoes that have exploited the global transportation network, land perturbation, and failure to contain the mosquito population coupled with enhanced vector competence. Ae. aegypti and Ae. albopictus may also sustain transmission between humans without having to depend on their natural reservoir forest cycles due to arthropod adaptation to urbanization. Currently, there is no single strategy that is adequate to control these vectors, especially when managing arbovirus outbreaks. Objective: This review aimed at presenting the characteristics and abilities of Ae. aegypti and Ae. albopictus, which can drive a global public health risk, and suggests strategies for prevention and control. Methods: This review presents the geographic range, reproduction and ecology, vector competence, genetic evolution, and biological and chemical control of these two mosquito species and how they have changed and developed over time combined with factors that may drive pandemics and mitigation measures. Conclusion: We suggest that more efforts should be geared toward the development of a concerted multidisciplinary approach.

Rift Valley Fever virus (RVFV) regularly accounts for severe and often lethal outbreaks among livestock and humans in Africa. Safe and effective veterinarian and human vaccines are highly needed. We present evidence that administration of RVF virus-like particles (VLPs) induces protective immunity in mice. In an accompanying paper, (Habjan, M., Penski, N., Wagner, V., Spiegel, M., Overby, A.K., Kochs, G., Huiskonen, J., Weber, F., 2009. Efficient production of Rift Valley fever virus-like particles: the antiviral protein MxA can inhibit primary transcription of Bunyaviruses. Virology 385, 400-408) we report the production of these VLPs in mammalian cells. After three subsequent immunizations with 1x10(6) VLPs/dose, high titers of virus-neutralizing antibodies were detected; 11 out of 12 mice were protected from challenge and only 1 out of 12 mice survived infection in the control groups. VLP vaccination efficiently suppressed replication of the challenge virus, whereas in the control animals high RNA levels and increasing antibody titers against the nucleocapsid protein indicated extensive viral replication. Our study demonstrates that the RVF VLPs are highly immunogenic and confer protection against RVFV infection in mice. In the test groups, the vaccinated mice did not exhibit any side effects, and the lack of anti-nucleocapsid protein antibodies serologically distinguished vaccinated animals from experimentally infected animals.

Background: Affecting both livestock and humans, Rift Valley Fever is considered as one of the most important viral zoonoses in Africa. However, no licensed vaccines or effective treatments are yet available for human use. Naked DNA vaccines are an interesting approach since the virus is highly infectious and existing attenuated Rift Valley Fever virus vaccine strains display adverse effects in animal trials. In this study, gene-gun immunisations with cDNA encoding structural proteins of the Rift Valley Fever virus were evaluated in mice. The induced immune responses were analysed for the ability to protect mice against virus challenge.