20 Dec 2013

Meeting of the Strategic Advisory Group of Experts on immunization, November 2013 – conclusions and recommendations (WHO, extract): H5N1 & H7N9 vaccines

[Source: World Health Organization, Weekly Epidemiological Record, full PDF document: (LINK). Excerpt.]

Weekly epidemiological record / Relevé épidémiologique hebdomadaire, 3 january 2014, 89th year / 3 janvier 2014, 89e année, No. 1, 2014, 89, 1–20, http://www.who.int/wer

Meeting of the Strategic Advisory Group of Experts on immunization, November 2013 – conclusions and recommendations

The Strategic Advisory Group of Experts (SAGE) on immunization1 met on 5–7 November 2013 in Geneva, Switzerland. This report provides a summary of the discussions, conclusions and recommendations.2

 

Report from the WHO Department of Immunization, Vaccines and Biologicals

The report focused on the scale up of immunization services required to reach the Global Vaccine Action Plan (GVAP) goal of 90% national coverage with 3 doses of diphtheria-tetanus-pertussis vaccine (DTP3) in all countries by 2015. This commitment will entail the vaccination of 9.3 million additional infants each year.

Recent successes such as the meningococcal A vaccine project and its impact on the burden of disease and carriage, as well as the delivery of the vaccine using the controlled temperature chain, were noted.

Updates were also provided on site-specific results of phase 3 clinical trials of the malaria RTS,S vaccine candidate, the prequalification of the live SA 14-14-2 Japanese encephalitis vaccine as the first WHO prequalified Chinese vaccine, and the life course and integrated approaches to promote the delivery of vaccination with other relevant interventions to children, adolescents, and pregnant women.

(…)

 

Pandemic and interpandemic influenza vaccines

In 2007, SAGE recommended policies for the establishment and use of influenza A(H5N1) vaccine stockpiles during a pandemic and in 2009, guidelines for the use of A(H5N1) vaccines during the inter-pandemic period.9

Since then, WHO developed the Pandemic Influenza Preparedness Framework (PIP Framework) for sharing influenza viruses and access to vaccines and other related benefits. The PIP Framework provides a model for legally binding contracts with individual vaccine manufacturers, so-called “Standard Material Transfer Agreements type-2 (SMTA2)” through which WHO will secure access, on a real-time basis, to pandemic vaccine at the time of a pandemic. As a result, WHO requested that previous recommendations regarding the constitution of a A(H5N1) vaccine stockpile and use of A(H5N1) vaccines be re-examined.

Based on the recognition that (a) the PIP Framework secures immediate access to pandemic vaccine production, (b) there is no significant change in A(H5N1) epidemiology, (c) there is a substantial risk of poor antigenic/strain match between the actual pandemic virus and stockpiled A(H5N1) vaccine and (d) the value of a stockpiled vaccine for containment of a nascent pandemic remains doubtful, SAGE agreed that WHO should not create a stockpile of A(H5N1) vaccine, but should ensure immediate access to pandemic vaccines under the PIP Framework. SAGE also highlighted the need for WHO (a) to ensure equitable access by lowand middle-income countries and (b) to put in place a strategy for timely communication of any delays in vaccine availability in case of a pandemic.

Regarding the question of inter-pandemic use of A(H5N1) vaccines (if and when available), SAGE agreed that (a) no clear change in the low level of risk to exposed populations has been observed, (b) no changes in populations at risk for highly pathogenic avian influenza (HPAI) H5N1 virus infection have been observed and (c) while risk remains low, even in exposed populations, certain high-risk groups may benefit from vaccination given the severity of the disease. Therefore, SAGE concluded that its previous recommendations on the use of A(H5N1) vaccine during inter-pandemic periods, mainly focusing vaccination of persons at high risk of A(H5N1) disease through occupational exposure, should remain unchanged.9

Finally, SAGE received a presentation on the epidemiologic situation regarding avian A(H7N9) virus and related vaccine development. As of 5 November 2013, 139 confirmed human cases of A(H7N9) influenza and 45 deaths (case-fatality rate 32.4%) were reported from China, mostly following exposure at live poultry markets.

There is currently no evidence showing sustained human-to-human transmission of A(H7N9) virus though continued sporadic human cases and small clusters can be expected. WHO has not issued any recommendations with regard to special screening procedures at entry points or any travel and trade restrictions.

Currently, 6 vaccine viruses have been developed using reverse genetics, while efforts using classical reassortant vaccines have so far been unsuccessful.

There are 5 clinical trials ongoing for A(H7N9) influenza vaccines.

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(1) See http://www.who.int/immunization/sage/en/index.html

(2) The complete set of presentations and background materials used for the SAGE meeting of 5–7 November 2013 together with summarized declarations of interests provided by SAGE members are available at; http://www.who.int/immunization/sage/meetings/2013/november/en/index.html accessed in November 2013.

(9) See No. 24, 2009, pp. 244–248.

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