Immunization, Vaccines and Biologicals

Progress in pandemic influenza vaccine preparedness

24 February 2009

The epidemiologic situation with H5N1 viruses

Total cases recorded since February 2003: 408 cases

Deaths recorded since February 2003: 254 deaths

Case-fatality ratio (Number of deaths per number of cases): 62%

What is happening in 2009: 13 cases including 4 deaths have been reported: China reported 7 cases including 4 deaths; 4 cases occurred in Egypt and 2 were reported in Viet Nam.

What happened in 2008: 44 cases including 33 deaths reported in six countries (Bangladesh, Cambodia, China, Egypt, Indonesia, Viet Nam)

Countries affected since 2003:15 (Azerbaijan, Bangladesh, Cambodia, China, Djibouti, Egypt, Indonesia, Iraq, Lao PDR, Myanmar, Nigeria, Pakistan, Thailand, Turkey, Viet Nam)

The level of preparedness of countries for pandemic influenza

  • Most of the countries in the world have made pandemic influenza preparedness plans using WHO guidance since 2005.
  • Many of these plans have been exercised and revised.
  • Countries with H5N1 have, in general, been more active in preparedness due to a perceived closeness of the risk.
  • For the gains to be sustainable, however, pandemic influenza preparedness needs to be placed into the wider scope of national emergency preparedness and should be used to strengthen national capacities.
  • The challenge now is a misperception that the risk of a pandemic is lower than before; it is not.

Next steps on pandemic influenza preparedness

WHO is in the process of revising its global influenza preparedness plan (current version published in 2005). The revised guidance promotes a whole-of-society approach to pandemic preparedness, and introduces revised phase definitions based on observable phenomena, pandemic severity issues and a more pronounced presence of ethics and communications.

The significance of the WHO-Nobilon agreement

WHO and Nobilon (the vaccines division of Schering-Plough) have signed an agreement at WHO's headquarters in which WHO has been granted a non-exclusive license to develop, register, manufacture, use and sell seasonal and pandemic live, attenuated (or weakened) influenza vaccines (LAIV) produced on chicken eggs. WHO will thus be able to grant sub-licenses to vaccine manufacturers in developing countries who are working within the framework of the WHO Global Pandemic Influenza Action Plan to Increase Vaccine Supply (link below). These countries will be able to provide such vaccines to their public sectors royalty-free. This last provision is of upmost importance to allow access to developing countries to this technology and contributes to a more equitable sharing of benefits.

Many experts have identified Live Attenuated Influenza Vaccine (LAIV) technology as the most promising approach for supporting national or regional pandemic influenza vaccine preparedness plans.

LAIVs have at least three major advantages compared to the currently available inactivated vaccines.

  • The number of doses of LAIV which can be produced per egg are much higher than with inactivated vaccines. Especially in a pandemic situation, this is considered to be a major advantage since more vaccine doses can be made available in a shorter time.
  • LAIVs are administered in the nose though a very simple device, which will be much easier to put into practice on a large-scale by non-medically trained staff in case of a pandemic.
  • Since a LAIV mimics natural infection more than injectable vaccines, it is expected that LAIV induces a more rapid and broader immune response. This may be of particular interest in pandemic situations.

WHO's assessment of the new pandemic influenza vaccine supply estimates

Although the newly expanded production capacity (see 24.02.09 IFPMA press release) would not be sufficient to meet the global need for emergency production of pandemic influenza vaccines at the time of a pandemic, it appears that current and future surplus capacity could support the production of billions of doses of H5N1 influenza vaccine prior to a pandemic for stockpiling efforts and other utilization.

This, however, will still be insufficient to meet vaccine demand in case of a pandemic. Therefore, transfer of technology to developing country vaccine manufacturers should continue to be promoted. A new call for proposals from developing countries interested in establishing or improving their influenza vaccine production capacity has been issued by WHO, both for continuation of the 6 current technology transfer projects and initiation of new ones. Applications have been reviewed by an independent technical advisory committee and WHO is negotiating further funding allocations with all 6 original grantees. The following have been designated for new (first) grants: Vacsera (Egypt), Green Cross (Korea), Cantacuzino (Romania), Torlak (Serbia), Razi (Iran). The total global value of all the grants (both groups of countries and both rounds) is about US $12 million.

Source: WHO Initiative for Vaccine Research; WHO Global Influenza Programme; 24 February 2009

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Melinda HENRY
Immunization, Vaccines and Biologicals,
World Health Organization,
Tel.: +41 22 791 2535