Exploiting the Legacy of the Arbovirus Hunters.

In recent years, it has become evident that a generational gap has developed in the community of arbovirus research. This apparent gap is due to the dis-investment of training for the next generation of arbovirologists, which threatens to derail the rich history of virus discovery, field epidemiology, and understanding of the richness of diversity that surrounds us. On the other hand, new technologies have resulted in an explosion of virus discovery that is constantly redefining the virosphere and the evolutionary relationships between viruses.

In Vitro Characterization and In Vivo Effectiveness of Ebola Virus Specific Equine Polyclonal F(ab')2.

There is no vaccine or approved therapy against lethal Ebola virus (EBOV). We investigated a proven technology platform to produce polyclonal IgG fragments, F(ab')2, against EBOV. Horses immunized with nanoparticles harboring surface glycoprotein trimers of EBOV-Zaire/Makona produced anti-Ebola IgG polyclonal antibodies with high neutralization activity.

Rational design of rabies vaccine formulation for enhanced stability.

Background/aim: Vaccines are often lyophilized in order to retain their stability and efficacy for a longer period of time. However, the same lyophilization process may also cause a major degradation of the vaccine, especially during early phases of manufacturing, leading to a loss of potency of the product. Many viral diseases, such as rabies, are acute and fatal unless the vaccine is administered prior to exposure or the onset of symptoms in the case of postexposure treatment.

The regulation of tumor suppressor protein, p53, and estrogen receptor (ERα) by resveratrol in breast cancer cells.

Resveratrol (RES) is a natural antioxidant found abundantly in grapes, peanuts, and berries, and is known to possess anti-tumorigenic properties. However, there is a noticeable lack of studies on the mechanistic effects of Resveratrol on tumor suppressors. Previous studies from our laboratory have shown the tumor suppressor protein p53 and estrogen receptor-alpha (ERα) to be possible molecular targets for RES.

Efficacy of a specific polyclonal equine F(ab')2 against avian influenza (H5N1) in ferrets: synergy with oseltamivir.

Aim: Current therapies against avian influenza (H5N1) provide limited clinical benefit. FBF-001 is a highly purified equine polyclonal immunoglobulin fragment against H5N1.

Methods: Using a ferret model of severe acute H5N1 infection, we assessed FBF-001 when administered on the same day or 1 day after viral challenge, in comparison with oseltamivir therapy.

Specific polyclonal F(ab')2 neutralize a large panel of highly pathogenic avian influenza A viruses (H5N1) and control infection in mice.

Aim: There is still no specific therapy for infection with the highly pathogenic avian influenza A virus (HPAI) H5N1, which caused 39 human cases with a 64% fatality rate in 2013.

Materials & Methods: We prepared highly purified specific equine polyclonal immunoglobulin fragments (F(ab')2) against H5N1 and tested them for efficacy in vitro and with different administration schedules in H5N1-challenged BALB/c mice.

Results: in vitro, F(ab')2 neutralized 21 different H5N1 strains from different areas, representative of 11 different clades and sub-clades and 9 years of evolution of the virus.

Immunogenicity of a thermally inactivated rotavirus vaccine in mice.

Current approaches to the prevention of severe rotavirus diarrhea and deaths in children have all been through the use of live oral vaccines. To develop a safe and effective inactivated rotavirus vaccine (IRV), a new simple, rapid and robust method for the inactivation is critical and essential because chemical inactivation commonly used for a number of killed vaccines has been a challenge and problematic for rotavirus. We have examined an array of thermal conditions and demonstrated that purified YK-1 rotavirus in diluent buffer can be completely inactivated by heat treatment, as evidenced by the lack of virus growth in two successive passages in cell culture.

Immunogenicity and safety of two live-attenuated tetravalent dengue vaccine formulations in healthy Australian adults.

We conducted a Phase 1b study to evaluate the immunogenicity and safety of two live attenuated tetravalent dengue vaccines in healthy adult volunteers. After one injection, all subjects reported systemic reactions consistent with a mild dengue-like syndrome. Seven volunteers developed dengue 3 viraemia after vaccination.

Safety and immunogenicity of a three dose regimen of two tetravalent live-attenuated dengue vaccines in five- to twelve-year-old Thai children.

Objective: The safety and immunogenicity of tetravalent live-attenuated dengue vaccines after a three dose vaccination series were evaluated in Thai children.

Method: One hundred three healthy flavivirus-seronegative schoolchildren ages 5 to 12 years were randomized to receive either dengue vaccine containing 3, 2, 1 and 2 log10 of the 50% cell culture infective dose, respectively, of the live-attenuated dengue vaccine serotypes 1, 2, 3 and 4 per dose (F3212; n = 40) or 3, 3, 1 and 3 log10 of the 50% cell culture infective dose (F3313; n = 42) or purified Vero cell rabies vaccine (control group; n = 21) given in a two dose schedule (3 to 5 months apart). A third dose was administered 8 to 12 months after the second dose to 90 subjects.

Safety and immunogenicity of tetravalent live-attenuated dengue vaccines in Thai adult volunteers: role of serotype concentration, ratio, and multiple doses.

Dengue fever, caused by four serotypes of a mosquito-borne virus, is a growing problem in tropical countries. Currently, there is no treatment or vaccine. We evaluated safety and immunogenicity of two doses, given six months apart, of seven formulations of dengue tetravalent live-attenuated vaccine (containing different concentrations of the component viruses) versus placebo in 59 flavivirus-seronegative Thai adults.

Short report: absence of protective neutralizng antibodies to West Nile virus in subjects following vaccination with Japanese encephalitis or dengue vaccines.

Protection of individuals against West Nile (WN) encephalitis is an emerging concern in the United States and Europe. We investigated whether immunization with licensed inactivated Japanese encephalitis (JE) vaccine or experimental live attenuated dengue vaccines resulted in induction of cross-neutralizing antibodies against WN virus. Protective neutralizing antibody titers to WN virus were not detected in any volunteer despite successful immunization to related flaviviruses.

Induction of T lymphocyte responses to dengue virus by a candidate tetravalent live attenuated dengue virus vaccine.

Development of a safe and immunogenic tetravalent dengue virus (DV) vaccine has been designated as a priority by the World Health Organization. We characterized the T cell response to DV induced by a candidate live attenuated tetravalent DV vaccine as part of a phase I study. Proliferation and cytotoxic T lymphocyte (CTL) responses to multiple DV serotypes were detected in six of six and four of four subjects studied, respectively.

Safety and immunogenicity of attenuated dengue virus vaccines (Aventis Pasteur) in human volunteers.

A randomized, controlled, double-blinded study was conducted to determine safety and immunogenicity of five live attenuated dengue vaccines produced by Aventis Pasteur (AvP). The study was completed with 40 flavivirus non-immune volunteers: five recipients of each monovalent (dengue-1, dengue-2, dengue-3, or dengue-4) vaccine, ten recipients of tetravalent (dengue-1, dengue-2, dengue-3, and dengue-4) vaccine, and ten recipients of vaccine vehicle alone. All vaccines were administered in a single subcutaneous dose (range, 3.

[Is there an alternative to the amaril 17D vaccine?].

The live attenuated yellow fever vaccine 17D was found as early as 1936 by M. Theiler of the Rockfeller Foundation. This strain of yellow fever is still the only one used today.

Experience with vero cells at Pasteur Mérieux Connaught.

The Vero cell line has been used by Pasteur-Merieux-Connaught (PMC) since 1982 with the Cell Bank's system to produce, at the 142nd passage, inactivated polio vaccine (IPV), oral polio vaccine (OPV) and rabies vaccines. The safety of the cell line has been regularly validated at the WCB level according to the WHO and European Pharmacopeia requirements for absence of bacteria, fungi, mycoplasma and viruses. Special emphasis was devoted to establishing the absence of simian viruses (SV40, SIV, Retro-D virus, simian CMV).

Characterization of clone 13, a naturally attenuated avirulent isolate of Rift Valley fever virus, which is altered in the small segment.

The 74HB59 strain of Rift Valley fever (RVF) virus, isolated from a human case in the Central African Republic, was shown to be composed of a heterogeneous population of viruses when plaque-purified clones were analyzed for their reactivity with monoclonal antibodies (MAbs) directed against the nucleocapsid (N) protein or the nonstructural (NSs) protein. One of these clones, C13, was of particular interest in that it proved to be avirulent in mice and hamsters, and highly immunogenic. Although C13 showed normal reactivity with a large panel of MAbs directed at the glycoproteins, it failed to react with specific MAbs or polyclonal antibodies directed at the NSs protein and with a specific MAb recognizing the N protein of the Egyptian strains.

Short report: isolation and partial characterization of a Puumala virus from a human case of nephropathia epidemica in France.

Puumala (PUU) virus (Bunyaviridae: Hantavirus), the etiologic agent of nephropathia epidemica (NE), the mid form of hemorrhagic fever with renal syndrome, is enzootic in Europe and has been known to occur in France since 1983. We report the first isolation of PUU virus in France and western Europe from a case of NE acquired in France. The virus was isolated from a serum collected in the acute phase of the clinical course by successive blind passages in Vero E6 cells.

Antigenic comparison of Ockelbo virus isolates from Sweden and Russia with Sindbis virus isolates from Europe, Africa, and Australia: further evidence for variation among alphaviruses.

The plaque-reduction neutralization test (PRNT) was used to compare 15 isolates of Ockelbo virus from Sweden, one isolate of Ockelbo virus from Russia, the Egyptian prototype Sindbis virus, and Sindbis-like viruses from Slovakia, South Africa, Cameroon, and Australia. Strains from northern Europe (Sweden and Russia) were indistinguishable by PRNT. We observed some antigenic variation between isolates of Sindbis virus from Europe, Africa, and Australia.

Rift Valley fever on the east coast of Madagascar.

In March 1990, a Rift Valley fever virus (RVFV) outbreak was suspected in the district of Fenerive on the east coast of Madagascar after an abnormally high incidence of abortions and disease in livestock. Sera from humans and cattle were tested for RVFV antibodies by immunofluorescence assay (IFA) and ELISA-IgM capture. Sera and mosquitoes collected in the same area were tested for virus isolation by tissue culture and suckling mouse intracerebral inoculation, and for antigen detection by an ELISA antigen capture assay.

[Epidemiology of Rift Valley fever in west Africa. 1. Serological investigation of small ruminants in Niger].

A serosurvey of Rift Valley Fever virus infection conducted among 557 sheep and 643 goats from Niger in 1986 points out that 2.8% of the 1,200 animals tested had RVF virus reacting antibodies. The circulation of the virus is demonstrated, as well for another phlebovirus related to RVF virus, the strain Arumowot.

Generation and transmission of Rift Valley fever viral reassortants by the mosquito Culex pipiens.

Reassortant viruses containing heterologous S and M genomic RNA segments were obtained from both mosquito and vertebrate hosts that had been coinfected with Egyptian and Senegalese strains of Rift Valley fever (RVF) virus. The origin of the S and M RNA segments in each plaque-cloned virus was determined with monoclonal antibodies capable of differentiating the nucleocapsid protein (S segment marker) or the G1 glycoprotein (M segment marker) of the parental strains. In the mosquito Culex pipiens, reassortants were detected after sequential ingestion of parental viruses by interrupted feeding on two infected hamster hosts, after feeding on a single host that had been infected with both parental strains, and from individual mosquitoes inoculated intrathoracically with both parental strains.

Use of reassortant viruses to map attenuating and temperature-sensitive mutations of the Rift Valley fever virus MP-12 vaccine.

A live-attenuated vaccine for Rift Valley fever virus (RVFV), MP-12, has been developed recently by undirected, serial mutagenesis of a RVFV strain (ZH548) isolated during the 1977 epidemic in Egypt. In the present study, the mutations responsible for attenuation of this virus have been examined by analysis of reassortant viruses generated between the vaccine strain and a wild RVFV strain isolated in Senegal. Reassortant viruses were generated efficiently in multiply infected Vero cells, and were readily isolated without application of selective pressures.