No abstract

Vaccines based on adenovirus (Ad) vectors are currently in development against several pathogens. However, neutralizing antibodies (NAb) to human adenovirus type 5 (AdHu5), the best-studied vector, are highly prevalent in humans worldwide. Less-prevalent adenoviruses, including human and simian serotypes, provide alternative vaccine platforms. In this study, sera from 200 Brazilian human subjects and New-World monkeys were tested for NAb titers to human serotypes AdHu5 and AdHu26 and chimpanzee-origin Ad viruses of serotype 6 (AdC6) and serotype 68 (AdC68). Seroprevalence rates of NAb in humans were 69.5% for AdHu5, 44% for AdHu26, 21% for AdC6 and 23.5% for AdC68. In addition, NAb titers to human Ad were consistently higher than those found to simian serotypes. Surprisingly, sera from some New-World monkey species were able to neutralize AdC6 and/or AdC68. A possible explanation for these findings and the implications for the development of Ad-vector vaccines are discussed in detail.

No abstract

This paper describes the screening of different South American plant extracts and fractions. Aqueous and organic extracts were prepared and tested for antiherpetic (HSV-1, KOS and 29R strains) and antirabies (PV strain) activities. The evaluation of the potential antiviral activity of these extracts was performed by using an MTT assay for HSV-1, and by a viral cytopathic effect (CPE) inhibitory method for rabies virus (RV). The results were expressed as 50% cytotoxicity (CC(50)) for MTT assay and 50% effective (EC(50)) concentrations for CPE, and with them it was possible to calculate the selectivity indices (SI = CC(50)/EC(50)) of each tested material. From the 18 extracts/fractions tested, six extracts and four fractions showed antiviral action. Ilex paraguariensis, Lafoensia pacari, Passiflora edulis, Rubus imperialis and Slonea guianensis showed values of SI > 7 against HSV-1 KOS and 29-R strains and Alamanda schottii showed a SI of 5.6 against RV, PV strain.

Recent studies have demonstrated an increased prevalence of human immunodeficiency virus type 1 (HIV-1) subtype C in southern Brazil. Although Santa Catarina State (SC) is located in this area and presents one of the country's highest incidences of HIV/AIDS, knowledge on the molecular epidemiology of HIV-1 in such State is lacking. The aim of this study was to investigate the HIV-1 molecular diversity and epidemiological profile of HIV-1-infected patients from SC. DNA samples were PCR amplified and HIV-1 subtypes were determined using both env and gag genes by direct sequencing. Phylogenetic analyses revealed that 48% were subtype C and 23% were subtype B. Possible recombinant forms were observed for both B/C (23%) and B/F (6%) subtypes. Our results, for the first time, identifies HIV-1 subtype C as a major clade circulating in SC and contributes to the understanding of HIV epidemics in the country by confirming the epidemic spread of the HIV-1 subtype C in southern Brazil.