• Data and product needs for influenza immunization programs in low- and middle-income countries: Rationale and main conclusions of the WHO preferred product characteristics for next-generation influenza vaccines

      Neuzil, Kathleen; Bresee, Joseph; Hoz, Fernando de la; Johansen, Kari; Karron, Ruth A.; Krishnan, Anand; Madhi, Shabir A.; Mangtani, Punam; Spiro, David J.; Ortiz, Justin R. (2017-08)
      In 2017, WHO convened a working group of global experts to develop the Preferred Product Characteristics (PPC) for Next-Generation Influenza Vaccines. PPCs are intended to encourage innovation in vaccine development. They describe WHO preferences for parameters of vaccines, in particular their indications, target groups, implementation strategies, and clinical data needed for assessment of safety and efficacy. PPCs are shaped by the global unmet public health need in a priority disease area for which WHO encourages vaccine development. These preferences reflect WHO’s mandate to promote the development of vaccines with high public health impact and suitability in Low- and Middle-Income Countries (LMIC). The target audience is all entities intending to develop or to achieve widespread adoption of a specific influenza vaccine product in these settings. The working group determined that existing influenza vaccines are not well suited for LMIC use. While many developed country manufactures and research funders prioritize influenza vaccine products for use in adults and the elderly, most LMICs do not have sufficiently strong health systems to deliver vaccines to these groups. Policy makers from LMICs are expected to place higher value on vaccines indicated for prevention of severe illness, however the clinical development of influenza vaccines focuses on demonstrating prevention of any influenza illness. Many influenza vaccine products do not meet WHO standards for programmatic suitability of vaccines, which introduces challenges when vaccines are used in low-resource settings. And finally, current vaccines do not integrate well with routine immunization programs in LMICs, given age of vaccine licensure, arbitrary expiration dates timed for temperate country markets, and the need for year-round immunization in countries with prolonged influenza seasonality. While all interested parties should refer to the full PPC document for details, in this article we highlight data needs for new influenza vaccines to better demonstrate the value proposition in LMICs.
    • Maternal Influenza Immunization and Prevention of Severe Clinical Pneumonia in Young Infants: Analysis of Randomized Controlled Trials Conducted in Nepal, Mali, and South Africa

      Omer, Saad B.; Clark, Dayna R.; Aqil, Anushka R.; Tapia, Milagritos D.; Nunes, Marta C.; Kozuki, Naoko; Steinhoff, Mark C.; Madhi, Shabir A.; Wairagkar, Niteen (Lippincott Williams & Wilkins, 2018)
      Background: To evaluate the effect of antenatal influenza vaccination on all-cause severe infant pneumonia, we performed pooled analysis of three randomized-controlled trials conducted in Nepal, Mali, and South Africa. Methods: The trials were coordinated from the planning phase. The follow-up period was 0–6 months post-partum in Nepal and Mali, and 0-24 weeks in South Africa. Pregnant women with gestational age 17-34 weeks in Nepal, ≥28 weeks in Mali, and 20-36 weeks in South Africa were enrolled. Trivalent Inactivated Influenza Vaccine (IIV). was compared with either saline placebo (Nepal and South Africa) or quadrivalent meningococcal conjugate vaccine (MCV) (Mali). In South Africa, cases were hospitalized, and were therefore considered to have severe pneumonia. In Nepal and Mali, severe infant pneumonia diagnosis was based on the WHO Integrated Management of Childhood Illness (IMCI) definition. Results: A total of 10,002 mothers and 9,801 live-born eligible infants were included in the present analysis. Incidence rate of severe pneumonia was 31% lower in the IIV group compared to the control group (incidence rate ratio [IRR]: 0.69, 95% CI: 0.50 - 0.94, P = 0.02). During periods with high influenza circulation there was lower incidence of severe pneumonia among the IIV group (IRR: 0.20, 95% CI: 0.06 - 0.74, P = 0.02), however, there was no difference in pneumonia incidence between study groups during periods of low and no influenza circulation. Conclusions: Maternal influenza immunization may reduce severe pneumonia episodes among infants –particularly those too young to be completely vaccinated against S. pneumoniae and influenza.