Consultation with Directors of WHO Collaborating Centres on Influenza: Memorandum from a WHO Meeting*

BulleUtin of the World Health Organization, 66 (4): 457-458 (1988) © World He&lth Organization 1988 Consultation with Directors of WHO Collaborating Centres on Influenza: Memorandum from a WHO Meeting* This Memorandum summarizes the conclusions and recommendations of the participants at the Consultation which was held in Geneva, Switzerland, on 17-18 February 1988 to discuss the WHO Programme for Influenza Surveillance. CONCLUSIONS AND RECOMMENDATIONS (1) The WHO Influenza Surveillance Programme has long been held as a model of international col- laboration and rapid exchange of information. It is important that this programme should be maintained and strengthened because, by facilitating the earliest possible detection of new epidemic strains of in- fluenza virus and recommending the use of new antigenic variants for vaccines, it provides the foundation for activities to prevent and control the disease. Most developed nations recommend the use of influenza vaccine annually in certain segments of their populations; more than 50 million doses of inactivated vaccine and another 50 million doses of live vaccine are used each year. The efficacy of these vaccines is ensured by annual recommendations for updating the component antigens so that they match the antigens of viruses isolated from recent out- breaks and epidemics. National control authorities look to this WHO programme as the most reliable source of information on which to base their vaccine formulation recommendations. Rapid reporting of the spread of influenza to alert health care providers who wish to prescribe an anti- viral drug (e.g., amantadine or rimantadine) is also very important. These drugs are a practical alterna- tive to vaccine for those who cannot or will not be immunized, or in situations where the vaccine is ineffective. However, early detection of virus spread is necessary in order to minimize inappropriate use of the drugs. (2) WHO can assist surveillance by encouraging national health authorities to direct their local health units not to overlook influenza in planning and imple- menting their infectious disease epidemiology pro- grammes. A national commitment to the principle * This Memorandum was drafted by the signatories listed on page 458 during their meeting in Geneva on 17-18 February 1988. Requests for reprints should be addressed to Microbiology and Immunology Support Services, World Health Organization, 1211 Geneva 27, Switzerland. A French translation of this article will appear in a later issue of the Bulletin. that virus isolation and identification should be under- taken at an adequate level to permit timely detection of virus spread can greatly encourage the efforts of local health units. (3) Methods for influenza virus surveillance that are potentially more cost-effective than traditional methods should be promoted (e.g., rapid methods for confirmation by cultivation and/or antigen detec- tion). However, antigen detection without virus isolation should not be relied upon exclusively because false positive results may cause difficulties, and isolates will not be available for strain character- ization. Balanced approaches will give the most reliable results. (4) Molecular techniques are proving to be useful for improving the detection ofnew influenza variants and for monitoring their spread. A transfer of mol- ecular biological techniques to several national influenza centres should be planned, since the infor- mation gained may be expected to assist the overall surveillance effort. (5) Recent research in several laboratories has shown that differences may exist between the viruses isolated in different types of cell. WHO should encourage research to determine the importance of this variation for influenza surveillance activities and vaccine preparation, and should also review current policy which assumes that viruses isolated in cell culture are not eligible to be used as seeds for inacti- vated vaccine production in eggs. (6) WHO can play a facilitating role and should continue to offer guidance and encouragement to scientists undertaking studies on the efficacy of influenza vaccine and on strategies for influenza control. Ongoing studies by WHO collaborators should be reviewed in one or two years when ad- equate data have been collected for detailed analysis. 4901 -457 458 MEMORANDUM LIST OF PARTICIPANTS M. Aymard, Laboratory of Virology, Claude Ber- nard University, Lyon, France A. P. Kendal, Influenza Branch, Viral Diseases Div- ision, Center for Infectious Diseases, Centers for Disease Control, Atlanta, GA, USA (Chairman) A. Klimov, Moscow Research Institute for Viral Preparations, Moscow, USSR G. C. Schild,* National Institute for Biological Stan- dards and Control, Potters Bar, Herts., England J. J. Skehel,* National Institute for Medical Research, Mill Hill, London, England * Unable to attend. Secretariat (WHO, Geneva, Switzerland) K. Esteves, Division of Communicable Diseases Y. Ghendon, Microbiology and Immunology Support Services (Secretary) P.-H. Lambert, Microbiology and Immunology Sup- port Services D. Magrath, Biologicals Y. Pervikov, Microbiology and Immunology Sup- port Services G. Torrigiani, Division of Communicable Diseases Observer C. Hannoun, Institut Pasteur, Paris, France