950 resultados para AIDS Vaccines
Resumo:
For 20 years, AIDS has continued its relentless spread across the globe. By the end of the year 2000, the United Nations’ Joint Programme on HIV/AIDS reported that 36.1 million men, women, and children around the world were living with HIV and 21.8 million had died of it. Though AIDS is now found in every country, it has most seriously affected sub-Saharan Africa - home to 70 % of all adults and 80 % of all children living with HIV, and the continent with the least medical resources in the world. Today, AIDS is the primary cause of death in Africa and it has had a devastating impact on villages, communities and families. In many African countries, the number of newly infected persons is increasing at a rate that is threatening to destroy the social fabric. Life expectancy is decreasing rapidly in many of these countries as a result of AIDS related illnesses and socioeconomic problems. Of the approximately 13.2 million children orphaned by HIV/AIDS worldwide, 12.1 million live in Africa.
Resumo:
Respiratory disease in beef calves has been associated with the stress of weaning. Management practices commonly delay vaccination of calves to this time, and weaning stress could potentially suppress the immune response. To reduce this stress we have been experimenting with a procedure termed “pasture weaning” in which the dams are removed and the calves remain on pasture. Observation suggests that calves weaned with this approach adapt to the weaned state much better than those held in drylot. Consequently, one would expect less stress-mediated effects including those on the immune system. Calves were weaned and assigned to groups that were pasture or drylot weaned, and calves within the groups were vaccinated with one of two inactivated virus vaccines by either the intramuscular or subcutaneous route. Weaning placement did not affect antibody responses to the viruses included in the vaccines. The route of administration did not influence responses with subcutaneous injection inducing responses equivalent to the intramuscular site. Utilization of this route for vaccination could be advantageous because it precludes the tissue damage and hidden abscessation that sometimes results from intramuscular injections. A distinct difference was noted in the immunogenicity of the vaccines with the Vira Shield product yielding significantly better responses to all viral entities.
Resumo:
The objective of this experimentation was to determine if circulating antibody titers to parainfluenza type-3 (PI-3) and infectious bovine rhinotracheitis (IBR) viruses could be enhanced by a combination of vaccines. The vaccines utilized were a modified live virus vaccine administered by the intranasal route and an inactivated virus vaccine injected intramuscularly. Virus neutralization tests were conducted on sera obtained at intervals before and following vaccination. Unfortunately, the calves were apparently exposed naturally to PI-3 virus, and the responses to that virus were inconclusive. However, antibody responses to IBR virus were dramatically enhanced by the combination of the two vaccines.
Resumo:
Three commercial inactivated virus vaccines were evaluated for immunogenicity in young calves with residual maternal antibodies. Groups of 30 calves were administered each of the vaccines at the start of the experimentation and were administered a second dose 32 days later. Serum was obtained from these calves and 30 calves in a nonvaccinated control group prior to vaccination and at 32, 61, 99 and 125 days thereafter. Antibody responses to viruses in two of the vaccines were extremely limited. The third vaccine overcame suppression by maternal antibodies and elicited responses clearly differentiated from antibody levels in the control group of calves.