About the Vaccine

The hookworm vaccine will be bivalent, possibly consisting of two larval/adult antigens. Vaccine protection would last into adulthood in order to protect women in pregnancy. Sabin’s Human Hookworm Vaccine Initiative (HHVI) has identified and produced several candidates for potential use in the vaccine.

Na-ASP-2, the vaccine antigen candidate that is the most advanced in the development process, has been evaluated in Phase 1 safety trials in the USA in 2006 and Brazil in 2007-2008. Immunization with the Na-ASP-2 antigen is intended to reduce the rate of larval hookworm migration to human body tissues, thereby preventing overall infection.

A second approach for hookworm vaccination relies on interfering with hookworm blood feeding at the site of attachment. Thus, two lead candidate antigens are also being developed to stimulate the human immune system to produce antibodies that inhibit parasite blood feeding. Na-GST-1 has shown promise as an adult hookworm vaccine and is scheduled for manufacturing in 2009, and clinical testing in 2010. Na-APR-1 has also demonstrated unique protection against adult hookworm, and is undergoing process development with clinical testing scheduled to begin in 2011. Ultimately, Na-GST-1 and Na-APR-1 may be combined in order to provided additive protection in the inhibition of hookworm-associated blood loss.

The hookworm vaccine is being developed and tested and may not be available for widespread use for years. Because hookworm affects only the world’s poorest people, this vaccine does not have a traditional commercial market. As a result, the HHVI partners with vaccine manufacturers, such as Instituto Butantan, and national health ministries in developing countries to assist with bringing the product to market and develop effective distribution strategies. These countries are defined by their modest economic capacity, but also their capacity to develop, patent, manufacture, ensure safety, market new health products and to develop, test, and introduce new health policies that support the products.