Dataset Information

Implementation of new approaches for generating conventional reassortants for live attenuated influenza vaccine based on Russian master donor viruses.

ABSTRACT: Cold-adapted influenza strains A/Leningrad/134/17/57 (H2N2) and B/USSR/60/69, originally developed in Russia, have been reliable master donors of attenuation for preparing live attenuated influenza vaccines (LAIV). The classical strategy for generating LAIV reassortants is robust, but has some disadvantages. The generation of reassortants requires at least 3 passages under selective conditions after co-infection; each of these selective passages takes six days. Screening the reassortants for a genomic composition traditionally starts after a second limiting dilution cloning procedure, and the number of suitable reassortants is limited. We developed a new approach to shorten process of preparing LAIV seed viruses. Introducing the genotyping of reassortants by pyrosequencing and monitoring sequence integrity of surface antigens starting at the first selective passage allowed specific selection of suitable reassortants for the next cloning procedure and also eliminate one of the group selective passage in vaccine candidate generation. Homogeneity analysis confirmed that reducing the number of selective passages didn't affect the quality of LAIV seed viruses. Finally, the two-way hemagglutination inhibition test, implemented for all the final seed viruses, confirmed that any amino acid substitutions acquired by reassortants during egg propagation didn't affect antigenicity of the vaccine. Our new strategy reduces the time required to generate a vaccine and was used to generate seasonal LAIVs candidates for the 2012/2013, 2014/2015, and 2015/2016 seasons more rapidly.

SUBMITTER: Shcherbik S

PROVIDER: S-EPMC4773654 | biostudies-literature | 2016 Jan

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Implementation of new approaches for generating conventional reassortants for live attenuated influenza vaccine based on Russian master donor viruses.

Shcherbik Svetlana S Pearce Nicholas N Kiseleva Irina I Larionova Natalie N Rudenko Larisa L Xu Xiyan X Wentworth David E DE Bousse Tatiana T

Journal of virological methods 20151028

Cold-adapted influenza strains A/Leningrad/134/17/57 (H2N2) and B/USSR/60/69, originally developed in Russia, have been reliable master donors of attenuation for preparing live attenuated influenza vaccines (LAIV). The classical strategy for generating LAIV reassortants is robust, but has some disadvantages. The generation of reassortants requires at least 3 passages under selective conditions after co-infection; each of these selective passages takes six days. Screening the reassortants for a g ...[more]

PMID: 26519883

Similar Datasets

Project description:BackgroundAvian influenza A (H7N9) virus has emerged recently and continues to cause severe disease with a high mortality rate in humans prompting the development of candidate vaccine viruses. Live attenuated influenza vaccines (LAIV) are 6:2 reassortant viruses containing the HA and NA gene segments from wild type influenza viruses to induce protective immune responses and the six internal genes from Master Donor Viruses (MDV) to provide temperature sensitive, cold-adapted and attenuated phenotypes.Methodology/principal findingsLAIV candidate A/Anhui/1/2013(H7N9)-CDC-LV7A (abbreviated as CDC-LV7A), based on the Russian MDV, A/Leningrad/134/17/57 (H2N2), was generated by classical reassortment in eggs and retained MDV temperature-sensitive and cold-adapted phenotypes. CDC-LV7A had two amino acid substitutions N123D and N149D (H7 numbering) in HA and one substitution T10I in NA. To evaluate the role of these mutations on the replication capacity of the reassortants in eggs, the recombinant viruses A(H7N9)RG-LV1 and A(H7N9)RG-LV2 were generated by reverse genetics. These changes did not alter virus antigenicity as ferret antiserum to CDC-LV7A vaccine candidate inhibited hemagglutination by homologous A(H7N9) virus efficiently. Safety studies in ferrets confirmed that CDC-LV7A was attenuated compared to wild-type A/Anhui/1/2013. In addition, the genetic stability of this vaccine candidate was examined in eggs and ferrets by monitoring sequence changes acquired during virus replication in the two host models. No changes in the viral genome were detected after five passages in eggs. However, after ten passages additional mutations were detected in the HA gene. The vaccine candidate was shown to be stable in the ferret model; post-vaccination sequence data analysis showed no changes in viruses collected in nasal washes present at day 5 or day 7.Conclusions/significanceOur data indicate that the A/Anhui/1/2013(H7N9)-CDC-LV7A reassortant virus is a safe and genetically stable candidate vaccine virus that is now available for distribution by WHO to vaccine manufacturers.

Project description:Diseases caused by human herpes simplex virus types 1 and 2 (HSV-1 and HSV-2) affect millions of people worldwide and range from fatal encephalitis in neonates and herpes keratitis to orofacial and genital herpes, among other manifestations. The viruses can be shed efficiently by asymptomatic carriers, causing increased rates of infection. Viral transmission occurs through direct contact of mucosal surfaces followed by initial replication of the incoming virus in skin tissues. Subsequently, the viruses infect sensory neurons in the trigeminal and lumbosacral dorsal root ganglia, where they are primarily maintained in a transcriptionally repressed state termed "latency", which persists for the lifetime of the host. HSV DNA has also been detected in other sympathetic ganglia. Periodically, latent viruses can reactivate, causing ulcerative and often painful lesions primarily at the site of primary infection and proximal sites. In the United States, recurrent genital herpes alone accounts for more than a billion dollars in direct medical costs per year, while there are much higher costs associated with the socio-economic aspects of diseased patients, such as loss of productivity due to mental anguish. Currently, there are no effective FDA-approved vaccines for either prophylactic or therapeutic treatment of human herpes simplex infections, while several recent clinical trials have failed to achieve their endpoint goals. Historically, live-attenuated vaccines have successfully combated viral diseases, including polio, influenza, measles, and smallpox. Vaccines aimed to protect against the devastation of smallpox led to the most significant achievement in medical history: the eradication of human disease by vaccination. Recently, novel approaches toward developing safe and effective live-attenuated vaccines have demonstrated high efficacy in various preclinical models of herpetic disease. This next generation of live-attenuated vaccines has been tailored to minimize vaccine-associated side effects and promote effective and long-lasting immune responses. The ultimate goal is to prevent or reduce primary infections (prophylactic vaccines) or reduce the frequency and severity of disease associated with reactivation events (therapeutic vaccines). These vaccines' "rational" design is based on our current understanding of the immunopathogenesis of herpesviral infections that guide the development of vaccines that generate robust and protective immune responses. This review covers recent advances in the development of herpes simplex vaccines and the current state of ongoing clinical trials in pursuit of an effective vaccine against herpes simplex virus infections and associated diseases.

Project description:Influenza virus still represents a considerable threat to global public health, despite the advances in the development and wide use of influenza vaccines. Vaccination with traditional inactivate influenza vaccines (IIV) or live-attenuated influenza vaccines (LAIV) remains the main strategy in the control of annual seasonal epidemics, but it does not offer protection against new influenza viruses with pandemic potential, those that have shifted. Moreover, the continual antigenic drift of seasonal circulating influenza viruses, causing an antigenic mismatch that requires yearly reformulation of seasonal influenza vaccines, seriously compromises vaccine efficacy. Therefore, the quick optimization of vaccine production for seasonal influenza and the development of new vaccine approaches for pandemic viruses is still a challenge for the prevention of influenza infections. Moreover, recent reports have questioned the effectiveness of the current LAIV because of limited protection, mainly against the influenza A virus (IAV) component of the vaccine. Although the reasons for the poor protection efficacy of the LAIV have not yet been elucidated, researchers are encouraged to develop new vaccination approaches that overcome the limitations that are associated with the current LAIV. The discovery and implementation of plasmid-based reverse genetics has been a key advance in the rapid generation of recombinant attenuated influenza viruses that can be used for the development of new and most effective LAIV. In this review, we provide an update regarding the progress that has been made during the last five years in the development of new LAIV and the innovative ways that are being explored as alternatives to the currently licensed LAIV. The safety, immunogenicity, and protection efficacy profile of these new LAIVs reveal their possible implementation in combating influenza infections. However, efforts by vaccine companies and government agencies will be needed for controlled testing and approving, respectively, these new vaccine methodologies for the control of influenza infections.

Dataset Information

Implementation of new approaches for generating conventional reassortants for live attenuated influenza vaccine based on Russian master donor viruses.

Publications

Implementation of new approaches for generating conventional reassortants for live attenuated influenza vaccine based on Russian master donor viruses.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets