At a #TropMed25 session this week on global health diplomacy, Maria Elena Bottazzi, PhD, co-director of Texas Children’s Center for Vaccine Development at Baylor College of Medicine in Houston, talked about applying the lessons she learned from developing a patent-free vaccine technology for COVID-19 to her current push to gain support for a hookworm vaccine.  

Her hope is that something analogous to the constellation of partnerships that backed the CORBEVAX and INDOVAC COVID vaccines, which earned her and vaccine co-creator Peter Hotez, MD, PhD, a Nobel prize nomination, can be replicated for the hookworm vaccine.  

The hookworm parasite affects more than 500 million people globally, causing stunting, cognitive disabilities and severe anemia, with children in sub-Saharan African bearing the greatest disease burden. Over the last few years, Bottazzi has worked closely with David Diemert, MD, a professor and infectious disease clinical trial expert at George Washington University (GWU), and other partners to develop a hookworm vaccine.  

The good news, she said, is that a safe and promising vaccine candidate has emerged from clinical trials, which have used a powerful controlled human hookworm infection (CHHI) model developed at GWU to demonstrate its efficacy. The bad news, she said, is that convincing funders, vaccine manufacturers, country officials and policy makers to embrace a stand-alone hookworm vaccine is a hard sell. The key reason is that health ministries, along with the WHO, are reluctant to add another vaccine to an already packed immunization schedule, which in turn makes funders and manufacturers reluctant to invest. 

The challenge has prompted Bottazzi, Diemert and their partners to pursue a new approach: combining a hookworm vaccine with one of the two malaria vaccines now being used in sub-Saharan Africa. A follow-up conversation with Bottazzi and Diemert revealed five reasons why this seemingly unusual proposal could provide a promising pathway— and not just for fighting hookworm. They believe it could be a trailblazer for the broader effort to integrate vaccines against other neglected tropical diseases (NTDs) into routine childhood immunization schedules.  

1. Hookworm and malaria both cause anemia and in large swaths of Africa struggling with a high burden of anemia, co-infections with malaria and hookworm are common. Bottazzi said that providing protection against both diseases with a single vaccine could offer an effective and affordable way to achieve significant progress against anemia, a condition that’s a major threat to maternal and child health. Bottazzi said that with their partners at PATH, a demand forecast assessment of co-endemic countries revealed that the majority of them would regard a hookworm-malaria combination as highly valuable. 
   
   
2. Leaders of national immunization programs in sub-Saharan Africa can now choose between two malaria vaccines, the RTS,S/ASO1 vaccine and the R21/Matrix-M vaccine. Adding hookworm could offer one of them a competitive advantage. Bottazzi said she has reached out to the companies that manufacture these malaria vaccines and they were “genuinely intrigued” by the combination concept.  
   
   
3. Adding hookworm protection to a malaria vaccine would not significantly increase the vaccine costs. Bottazzi said preliminary assessments indicate that it would cost only about 50 cents US per dose to add hookworm protection to one of the existing malaria vaccines. 
   
   
4. Developing a hookworm vaccine formulation that’s compatible with a malaria vaccine will be costly, but there are potential ways to find support. Bottazzi said that while she is not giving up on the “usual suspects,” including the National Institutes of Health, she’s also hopeful of garnering support from funding agencies such as the Wellcome Trust, Open Philanthropy and the Gates Foundation. In addition, she’s exploring potential contributions from some of the family foundations and what she called “high-net-worth” individuals in Texas that provided support for her institution’s COVID-19 vaccine project.  
   
   
5. A combination hookworm-malaria vaccine could become a model for a new generation of NTD vaccines. Bottazzi said that there are promising efforts underway to develop new vaccines against other NTDs, such as schistosomiasis and leishmaniasis — but they also may struggle to find support as standalone products. A successful malaria-hookworm vaccine, she said, could encourage funders and manufacturers to seek out ways to combine a new generation of NTD vaccines with other existing vaccines.