PPC: For malaria vaccines to prevent infection

Malaria vaccines: Preferred product characteristics and clinical development considerations

14 September 2022
Indication
Malaria
Intended use

Prevention of blood-stage infection due to P. falciparum and/or P. vivax malaria at the individual level. The vaccine may be indicated for malaria control, elimination and/or prevention of reintroduction post-elimination, and may have application in low-, moderate- and high-transmission settings.

Target population

To maximize the public health impact of an infection-prevention vaccine, the immediate need will be to target populations or age groups who experience high incidence of infection. However, community-wide effects on transmission could be achieved by vaccinating a substantial proportion of the population that infects mosquitoes. Potential changes in malaria epidemiology should be considered, anticipating shifts in ages with the highest infection incidence at the time vaccines become available.

Efficacy
The vaccine should dramatically reduce incidence of blood-stage infection (e.g. 90% over 12 months of follow-up post-immunization) at the individual level. A rational target level of efficacy should be justified in conjunction with targets for the duration of protection, variation of efficacy over time and other key drivers of public health impact in the primary target group. Thus, the initial efficacy and long-term dynamics of protection will be considered together.
Safety
The safety and reactogenicity of the vaccine should be comparable to or better than WHO-recommended vaccines in use in LMICs. Safety should also be demonstrated in high-risk or immunocompromised groups, such as HIV-infected children or adults. Developers should be aware of possible deferred increases in morbidity due to the dynamics of waning vaccine-induced immunity and reductions in naturally acquired immunity. Plans for assessment of such effects may be required either in Phase 3 or Phase 4 evaluation.
URL
https://www.who.int/publications/i/item/9789240057463
Product type
Vaccine
Status
Active
Safety

Formulation/presentation: Vaccines seeking WHO prequalification should meet WHO-defined criteria for programmatic suitability regarding formulation, presentation, packaging, thermostability and disposal. Dose regimen: Single dose for primary immunization is preferred, but additional doses (including annual doses) are likely to be needed for strong and/or long-lasting immunity (e.g. efficacy > 90% and/or duration > 1 year). Route of administration: Vaccines seeking WHO prequalification should not require an intravenous route of administration, a mandatory requirement by the PSPQ Working Group whereby compliance is compulsory at time of application to WHO prequalification. Durability of protection: The vaccine should dramatically reduce incidence of blood-stage infection (e.g. 90% over 12 months of follow-up post-immunization) at the individual level. A rational target level of efficacy should be justified in conjunction with targets for the duration of protection, variation of efficacy over time and other key drivers of public health impact in the primary target group. Thus, the initial efficacy and long-term dynamics of protection will be considered together. Stability and storage: Vaccines stable under refrigerated conditions (2–8°C) for 24 months are preferred. Vaccines or any component presented for WHO prequalification should not require storage at less than -20°C, a mandatory requirement by the PSPQ Working Group whereby compliance is compulsory at time of application to WHO prequalification. ID_272