Improved protection against Venezuelan equine encephalitis by genetic engineering of a recombinant vaccinia virus

An improved vaccine is needed against Venezuelan equine encephalitis (VEE) virus because the existing live attenuated vaccine, TC-83, causes a high incidence of adverse effects, and the Formalin-inactivated vaccine, C-84, does not protect against airborne infection. A recombinant vaccine had previously been constructed in which the VEE structural proteins were expressed by vaccinia virus. Although protection against subcutaneous challenge with VEE was achieved, the vaccine had limited efficacy against aerosolized virus. We made a similar construct (WR100) and compared its performance as a vaccine: a synthetic promoter was inserted upstream of the VEE coding sequence to increase the amount of VEE proteins produced, and a single nucleotide in the E2 glycoprotein gene was altered to enhance immunogenicity. The WR103 virus expressed greater amounts of VEE proteins on the surface of infected cells than did WR100, and this difference was production. Sera from mice immunized with WR103 contained elevated levels of antibody to VEE, and enhanced protection against subcutaneous challenge with the pathogenic Trinidad donkey strain was achieved. This altered construct could form the basis for a better vaccine against VEE.(Au)

Human T cell lymphotropic virus: necessity for and feasibility of a vaccine

Human T cell lymphotropic virus types I and II (HTLV-I/II) are endemic in certain areas of the world. The cause two life-threatening diseases, adult T cell leukaemia/lymphoma and tropical spastic paraparesis. A vaccine is needed because in developing countries there are no other feasible preventive interventions against these diseases and in Western countries intravenous drug users at high risk for HTLV-I and HTLV-II infections and the health workers in contact with such populations must be protected. We have developed a rat model in which we observed variations of susceptibility to viral infection between inbred strains, the most susceptible being Fischer F344, and the possibility of viral latency in the nervous system. We have prepared a recombinant adenovirus vector that expresses the HTLV-I envelope glycoprotein env in HeLa cells. A target human population in French Guyana, in which the prevalence rate reaches 5.6 percent in one ethnic group (Bonis), has been identified for possible intervention (AU)

Congenital yellow fever virus infection after immunization in pregnancy

To determine whether yellow fever (YF) vaccine administered in pregnancy causes fetal infection, women who were vaccinated during unrecognized pregnancy in a mass campaign in Trinidad were studied retrospectively. Maternal and cord or infant blood were tested for IgM and neutralizing antibodies to YF virus, indicating congenital infection. The infant, the first repotred case of YF virus infection after immunization in prgnancy, was delivered after an uncomplicated full-term pregnancy and appeared normal. Congenital dengue 1 infection may have occurred in another case. The frequency of fetal infection and adverse events after such exposure could not be estimated; however, the neurotropism of YF virus for the developing nervous system and the now documented possibility of trans-placental infection underscores the admonition that YF vaccination in pregnancy should be avoided (AU)

Update on the virology of AIDS

This article looks at the history, development, progress and research of the Human Immunodeficiency Virus (HIV) which causes AIDS. The author reports of the ongoing research into a vaccine for HIV, he examines the viral life cycle and indicates the points at which the virus can be attacked, and classifies antiviral strategies

Simultaneous vaccination against cholera and yellow fever

A study of serum-samples from immunised individuals showed that administration of yellow-fever and cholera vaccine, simultaneously or one to three weeks apart, reduced the vibriocidal and yellow-fever-virus-neutralising antibody titres (AU)

Trials with a live attenuated rubella virus vaccine, Cendehill strain

This report summarizes closed, family, and open studies conducted sequentially over a 10 month period with the Cendehill rubella virus vaccine in more than 16,000 children and adolescents. This strain of rubella was attenuated by serial propogation on primary rabbit kidney cell cultures. Inoculation of the Cendehill vaccine produced seroconversion in 97 percent of the 3589 susceptible (seronegative) vaccinated persons. There was no spread of the virus to susceptible controls living in close contact with those vaccinated. The vaccine was well tolerated. No arthritis or arthralgia occured in 860 female subjects 13-18 years of age who were included in the study. The Cendehill vaccine would appear to meet the requirements of an acceptable vaccine (Summary)

The use of adjuvant and sarcoma 180 cells in the production of mouse hyperimmune ascitic fluids to arboviruses

A method for producing large volumes of mouse ascitic fluids with high viral antibody titers by the use of adjuvant in combination with Sarcoma 180 cells is described. Ascitic fluids so produced reacted specifically with the viruses to which they were prepared. In cross complement-fixation and hemagglutination-inhibition tests, none of 26 ascitic fluids prepared to individual viruses and of nine polyvalent ascitic fluids reacted with antigens outside the recongnized or artificial grouping. Satisfactory neutralization indices were obtained with the ascitic fluids tested.(AU)