WHO issues policy recommendation for new type of insecticide treated nets – an important milestone for malaria prevention tools
IVCC is delighted to announce that WHO-GMP has issued a policy recommendation for pyrethroid-chlorfenapyr nets to be deployed for malaria prevention instead of pyrethroid-only nets in areas with pyrethroid resistance. Pyrethroid-chlorfenapyr nets, such as the Interceptor® G2 has previously been assessed by the WHO Prequalification vector control products team for efficacy, safety and quality and were added to the list of Pre-Qualified vector control products in January 2018.
Epidemiological trials carried out over a 24-month period, in Tanzania (funded by the Wellcome Trust) and Benin (funded by Unitaid and the Global Fund as part of the New Nets Project) demonstrated that Interceptor® G2 nets reduced malaria incidence by 44% to 46%  when compared with standard, pyrethroid-only nets. Results from these trials were used by WHO to recognise the public health value of this new product against malaria.
The research to support these findings was conducted by the London School of Hygiene and Tropical Medicine (LSHTM), National Institute for Medical Research, Kilimanjaro Christian Medical University College, and the University of Ottawa and the Centre de Recherche Entomologique de Cotonou (CREC).
The collaboration between BASF and IVCC has delivered a next generation active ingredient treated net formulation that fights insecticide resistant mosquitoes. Interceptor® G2, combines a new to public health active ingredient, a pyrrole (chlorfenapyr), with a pyrethroid (alphacypermethrin), representing a novel mode of action in vector control and a first in 30 years.
“IVCC has a long-standing relationship with BASF; particularly when it comes to development of Interceptor® G2. We are pleased to have played a core role, alongside our partners, in early product development, field testing, and global access strategy for this important new malaria prevention tool. This milestone is also testament to the importance of product-development and other partnerships to deliver high-impact, cost-effective prevention tools that are adapted to the needs of endemic countries,” says Justin McBeath, IVCC CEO.
The New Nets Project (NNP), an IVCC-led consortium of partners, funded by Unitaid and The Global Fund, piloted the use of Interceptor® G2 nets in areas of moderate to high transmission throughout sub-Saharan Africa. The nets were first deployed in Burkina Faso in 2019, followed by an additional twenty countries from 2020 to 2023.
Over the course of four years, the project added to the necessary evidence base to support a WHO policy recommendation and assessed the effectiveness and cost-effectiveness of the new nets under programmatic conditions to help inform country decision making. Evidence generated during pilot deployment has mirrored the trial results, demonstrating the superior effectiveness of the Interceptor ® G2 compared to standard nets.
“We are pleased with the recommendation by the WHO for pyrethroid-chlofenapyr nets. Interceptor® G2 nets are making a significant contribution to prevent and fight against malaria. The partnership and commitment of all New Nets Project partners are key to bring innovations to regions where they demonstrate a public health value. This motivates us once again to continue developing new tools and products to reduce the burden of malaria to communities fighting insecticide resistance”, says Achim Reddig, Director of BASF Global Public Health.
The catalytic market shaping work under NNP to increase supply and demand have laid the foundation for ensuring equitable and affordable access to novel vector control products. This was enhanced by the joint work of UK-based social finance company MedAccess and the Bill & Melinda Gates Foundation who supported access to Interceptor® G2 nets in 20+ countries by providing a volume guarantee that enabled BASF to reduce the price procurers pay for the nets.
“Unitaid and the Global Fund played a critical role in supporting the catalytic introduction of these new bed nets, working with partners to bring down costs, increase demand, and prove the efficacy and effectiveness of this powerful new malaria-fighting tool. We are delighted to see our massive partnership effort delivering such a vital addition to the vector control toolbox, helping to combat insecticide resistance and ensure effective protection from malaria for millions of people every year.” – Dr Philippe Duneton, Executive Director of Unitaid.
“This shows how we can accelerate impact by embracing innovation,” said Peter Sands, Executive Director of the Global Fund. “The issuance of policy guidance by WHO is critical to influencing broad uptake of the new nets and to combat growing insecticide resistance across Africa, where nearly all malaria infections and related deaths occur.”
The combined evidence built by the NNP, along with the WHO recommendation, provides countries with a state-of-the-art tool as they make decisions about how best to spend their malaria control budgets.
During the New Nets Project, Disease Control Technologies’ (DCT) RoyalGuard® pyriproxyfen-pyrethroid nets were also tested. Based on the evidence available, WHO-GMP has issued a conditional recommendation for the use of this class of net compared to standard, pyrethroid-only nets. Lower net use in the RoyalGuard® groups in epidemiological trials could have contribute to the reduced impact of these nets. More research is needed to fully understand the results.
The epidemiological studies will report additional data once the 36-month period is reached and combined with New Net Pilot evidence pilots across 5 countries, will continue to contribute to the understanding of Interceptor® G2 and RoyalGuard® product performance over time and across various endemicities and resistance profiles.
Mosha JF, Kulkarni MA. et al. Effectiveness and cost-effectiveness against malaria of three types of dual active-ingredient long-lasting insecticidal nets (LLINs) compared with pyrethroidonly LLINs in Tanzania: a four-arm, cluster-randomised trial, 2022; 399, 10331: 1227-1241.
Accrombessi M, Cook J. et al. Efficacy of pyriproxyfen-pyrethroid long-lasting insecticidal nets (LLINs) and chlorfenapyr-pyrethroid LLINs compared with pyrethroid-only LLINs for malaria control in Benin: a cluster-randomised, superiority trial, 2023 (Online first).
Read the New Nets Project partner releases:
Global Fund and Unitaid Welcome WHO Recommendation for Insecticide-treated Nets With Dual Active Ingredients (Global Fund and Unitaid press release)
WHO recommends new malaria nets based on research by LSHTM and partners (LSHTM press release)
MedAccess welcomes WHO recommendation for chlorfenapyr-pyrethroid mosquito nets (MedAccess news item)
For further information contact:
Laura Roberts, Communications Manager
(+44) 07849 700582
Product and Project information
Interceptor® G2 is a second-generation ITN developed by BASF with a combination of chlorfenapyr and alpha-cypermethrin to control insecticide resistant mosquitoes. This novel mode of action in vector control exploits mosquito enzymatic systems against themselves and shows no cross-resistance to other insecticide classes. Unlike pyrethroids, the chlorfenapyr target site of activity is not the insect nervous system. Instead, chlorfenapyr acts, after being metabolized by P450 enzymes at the cellular level, by disrupting respiratory pathways and proton gradients through the uncoupling of oxidative phosphorylation within the mitochondria. The Interceptor® G2 net has a WHO prequalification listing.
Royal Guard® is an ITN developed by Disease Control Technologies to provide vector control through both the personal protection of traditional mosquito knockdown and mortality, as well as a reduction in fecundity of any mosquitoes that manage to survive exposure to the products pyrethroid active ingredient. The intended benefit of the insect growth regulator, pyriproxyfen, is to reduce the fecundity of adult female mosquitoes and, therefore, yield an overall reduction in the vector population by inhibiting egg laying, larval-pupal transformation and the emergence of functioning young adult mosquitos. The Royal Guard® net has a WHO prequalification listing.
The New Nets Project (NNP)
The Global Fund and Unitaid are each investing US$33 million between 2018 to 2022 to introduce new insecticide-treated nets to fight malaria-carrying mosquitoes. The New Nets Project is working to build the evidence base around, and prime the market for, the next generation of nets, which are treated with two different types of insecticide to help improve control of mosquitoes.
The project will generate evidence on the efficacy and cost-effectiveness of the new dual insecticide nets to inform a WHO policy decision on dual-AI nets and guide decision-making around product procurement at the country level. It is expected that the New Nets Project – with its unique design of parallel collection of epidemiological data and cost-effectiveness studies – will significantly reduce the timeline for entry of the new nets into the market.
The U.S. President’s Malaria Initiative and the Bill & Melinda Gates Foundation are key operational and financial partners. A coalition led by IVCC is implementing the project which includes The Alliance for Malaria Prevention, Imperial College London, The Liverpool School of Tropical Medicine, PATH, PSI and Tulane University.
IVCC is the only Product Development Partnership (PDP) focused on solutions for vector control. IVCC was established in 2005, through an initial grant to the Liverpool School of Tropical Medicine (LSTM) from the Bill & Melinda Gates Foundation. As a registered charity in the UK, IVCC receives grant funding from the Bill & Melinda Gates Foundation, UK Aid, USAID, The Swiss Agency for Development and Cooperation and the Australian Department of Foreign Affairs and Trade to partner with different stakeholders across industry, scientific institutions and endemic countries to facilitate the development and availability of novel and improved public health insecticides and formulations which can combat the rapidly growing problem of insecticide resistance. In addition, IVCC has received funding from Unitaid and the Global Fund to implement catalytic market access projects, such as NgenIRS and the New Nets Project which support the rapid and scaled deployment of vector control tools. IVCC has three core values of partnership, innovation and respect, and strives to live these values in our dealings with all partners.
Image credit: PSI, Mali.