Shigella Vaccine Development is a Priority for the US Army

Enesi Pharma’s ImplaVax technology to create a solid dose of Shigella flexneri 2a artificial Invaplex (Sfl2a InvaplexAR) vaccine
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(Precision Vaccinations)

There is some good news regarding a vaccine to protect against an infectious disease caused by a group of bacteria called Shigella.

A vaccine to protect against Shigella is a high priority for the US Army and is equally important for pediatric populations in endemic areas of the world.

To meet these needs, Enesi Pharma has entered a Cooperative Research and Development Agreement (CRADA) with the Walter Reed Army Institute of Research (WRAIR), a United States Department of Defense Laboratory, to develop a solid dose Shigella vaccine.

The CRADA is focused on the development of a robust and stable solid-dose formulation of WRAIR’s Shigella flexneri 2a artificial Invaplex (Sfl2a InvaplexAR) vaccine for delivery via Enesi Pharma’s ImplaVax® technology. 

Dr Robert Kaminski, Chief, Subunit Enteric Vaccines & Immunology, Branch of Bacterial Diseases at WRAIR, said in a press release, “The potential benefits of Enesi’s ImplaVax system should be considered with respect to vaccination against Shigella, particularly in those challenging environments where storage and retention of activity is a critical factor.’

Under the collaboration, WRAIR’s Invaplex Shigella vaccine will be provided to Enesi, and Enesi will create a solid-dose formulation for needle-free injection using its ImplaVax® technology.

Currently, a phase 1 study is investigating the S. flexneri 2a InvaplexAR vaccine in up to 40 subjects. 

Previously, a phase 2 study researched a safe and immunogenic dose of Invaplex 50 intranasal vaccine, and to assess the protection of Invaplex 50 intranasal vaccine against diarrhea, dysentery, and fever following challenge with the Shigella flexneri 2a 2457T strain.

According to the World Health Organization (WHO), Shigella infection is the most communicable form of the bacterial diarrhoeal disease and is responsible for approximately 165 million cases of severe dysentery each year.

More than one million people are estimated to die from shigellosis each year, says the WHO.

In addition, some 580,000 cases of shigellosis per year are reported among travelers and military personnel from industrialized countries.

Shigellosis is caused by the ingestion of bacteria of the genus Shigella.

Four species of Shigella are responsible for the majority of infections:

  • S. flexneri is the most frequently isolated species worldwide, accounting for most cases in the least-developed countries;
  • S. sonnei is more common in low- and middle-income countries;
  • S. dysenteriae has historically caused epidemics of dysentery, particularly in confined populations such as refugee camps; and
  • A fourth species, S. boydii, a cause of infection in less-developed countries, accounts for 6 percent or less of Shigella cases.

For additional information, contact Enesi Pharma Limited, +44 (0) 1235 577 120 pr general enquiries: [email protected]