H5N1-SeroDetect EIA and rapid test: a novel differential diagnostic assay for serodiagnosis of H5N1 infections and surveillance.

Continuing evolution of highly pathogenic (HP) H5N1 influenza viruses in wild birds with transmission to domestic poultry and humans poses a pandemic threat. There is an urgent need for a simple and rapid serological diagnostic assay which can differentiate between antibodies to seasonal and H5N1 strains and that could provide surveillance tools not dependent on virus isolation and nucleic acid technologies. Here we describe the establishment of H5N1 SeroDetect enzyme-linked immunosorbent assay (ELISA) and rapid test assays based on three peptides in HA2 (488-516), PB1-F2 (2-75), and M2e (2-24) that are highly conserved within H5N1 strains. These peptides were identified by antibody repertoire analyses of H5N1 influenza survivors in Vietnam using whole-genome-fragment phage display libraries (GFPDLs). To date, both platforms have demonstrated high levels of sensitivity and specificity in detecting H5N1 infections (clade 1 and clade 2.3.4) in Vietnamese patients as early as 7 days and up to several years postinfection. H5N1 virus-uninfected individuals in Vietnam and the United States, including subjects vaccinated with seasonal influenza vaccines or with confirmed seasonal virus infections, did not react in the H5N1-SeroDetect assays. Moreover, sera from individuals vaccinated with H5N1 subunit vaccine with moderate anti-H5N1 neutralizing antibody titers did not react positively in the H5N1-SeroDetect ELISA or rapid test assays. The simple H5N1-SeroDetect ELISA and rapid tests could provide an important tool for large-scale surveillance for potential exposure to HP H5N1 strains in both humans and birds.

HIV-Selectest enzyme immunoassay and rapid test: ability to detect seroconversion following HIV-1 infection.

HIV-Selectest is a serodiagnostic enzyme immunoassay (EIA), containing p6 and gp41 peptides, designed to differentiate between vaccine-induced antibodies and true infections. A rapid test version of the HIV-Selectest was developed. Both assays detected HIV antibodies in men and women within 2 to 4 weeks of infection, with sensitivity similar to third-generation EIAs.

Strengthening the influenza vaccine virus selection and development process: Report of the 3rd WHO Informal Consultation for Improving Influenza Vaccine Virus Selection held at WHO headquarters, Geneva, Switzerland, 1-3 April 2014.

Despite long-recognized challenges and constraints associated with their updating and manufacture, influenza vaccines remain at the heart of public health preparedness and response efforts against both seasonal and potentially pandemic influenza viruses. Globally coordinated virological and epidemiological surveillance is the foundation of the influenza vaccine virus selection and development process. Although national influenza surveillance and reporting capabilities are being strengthened and expanded, sustaining and building upon recent gains has become a major challenge. Strengthening the vaccine virus selection process additionally requires the continuation of initiatives to improve the timeliness and representativeness of influenza viruses shared by countries for detailed analysis by the WHO Global Influenza Surveillance and Response System (GISRS). Efforts are also continuing at the national, regional, and global levels to better understand the dynamics of influenza transmission in both temperate and tropical regions. Improved understanding of the degree of influenza seasonality in tropical countries of the world should allow for the strengthening of national vaccination policies and use of the most appropriate available vaccines. There remain a number of limitations and difficulties associated with the use of HAI assays for the antigenic characterization and selection of influenza vaccine viruses by WHOCCs. Current approaches to improving the situation include the more-optimal use of HAI and other assays; improved understanding of the data produced by neutralization assays; and increased standardization of serological testing methods. A number of new technologies and associated tools have the potential to revolutionize influenza surveillance and response activities. These include the increasingly routine use of whole genome next-generation sequencing and other high-throughput approaches. Such approaches could not only become key elements in outbreak investigations but could drive a new surveillance paradigm. However, despite the advances made, significant challenges will need to be addressed before next-generation technologies become routine, particularly in low-resource settings. Emerging approaches and techniques such as synthetic genomics, systems genetics, systems biology and mathematical modelling are capable of generating potentially huge volumes of highly complex and diverse datasets. Harnessing the currently theoretical benefits of such bioinformatics ("big data") concepts for the influenza vaccine virus selection and development process will depend upon further advances in data generation, integration, analysis and dissemination. Over the last decade, growing awareness of influenza as an important global public health issue has been coupled to ever-increasing demands from the global community for more-equitable access to effective and affordable influenza vaccines. The current influenza vaccine landscape continues to be dominated by egg-based inactivated and live attenuated vaccines, with a small number of cell-based and recombinant vaccines. Successfully completing each step in the annual influenza vaccine manufacturing cycle will continue to rely upon timely and regular communication between the WHO GISRS, manufacturers and regulatory authorities. While the pipeline of influenza vaccines appears to be moving towards a variety of niche products in the near term, it is apparent that the ultimate aim remains the development of effective "universal" influenza vaccines that offer longer-lasting immunity against a broad range of influenza A subtypes.