WHO has taken the lead in the effort to make donated pandemic influenza A (H1N1) vaccines available to 17 countries in the Western Pacific Region. All the pandemic influenza A (H1N1) vaccines to be supplied through WHO require to be prequalified. All 4 types of vaccines which are planned to be supplied in the countries of Western Pacific Region are already prequalified.
On the programmatic side, indications for immunization and using multi-dose vial policy (MDVP) are included in the manufacturer's packaging inserts, which remain the basis for utilization. However, for the purpose of pandemic influenza A (H1N1) vaccines deployed by WHO, a simplified approach has been proposed for immunization schedules and multi-dose vial policy by WHO.
Proposal for indications for immunization of inactivated pandemic influenza A (H1N1) vaccines:
In line with the recommendations from manufacturers and national regulatory authorities and taking into consideration SAGE recommendations, WHO advises:
- for adolescents and adults aged 10 years or more, to give a single-dose* of vaccine;
- for children aged more that 6 months and less than 10 years, to give a single-dose* of vaccine, in view of the shortage of vaccine in developing countries. Countries using vaccine where two doses are recommended by the manufacturer may consider giving a second dose as limitation of supply eases, and subject to regulatory considerations;
- for children less than 6 months, immunization is not recommended;
- for pregnant women, WHO advises to give a single dose* of vaccine.
Proposal for usage of multi-dose vials for inactivated influenza A (H1N1) vaccine:
Considering the concentration of preservatives and taking into consideration the revised WHO multi-dose vial policy (MDVP)** WHO advises:
- All WHO prequalified pandemic influenza H1N1 vaccines, except GSK vaccines, from which one or more doses of vaccine have been removed during an immunization session may be used in subsequent immunization sessions for up to a maximum of 28 days, provided that all stability/sterility conditions are met**.
- GSK vaccines (Arepanrix and Pandemrix), containing a low concentration of thiomersal, may be used in subsequent immunization sessions for up to a maximum of 24 hours, provided that all stability/sterility conditions are met**.