Chikungunya vaccine - coming shortly

PaxVax, a leading independent specialty vaccine company, announced that it has received Fast Track designation by the U.S. Food and Drug Administration (FDA) for development of its vaccine meant for prevention of disease caused by chikungunya virus.

The vaccine was licensed from the National Institute of Allergy and Infectious Diseases (NIAID) at National Institutes of Health (NIH). PaxVax recently announced the enrollment of the first patient in its Phase 2b dose-finding trial of the chikungunya virus-like particle (VLP) vaccine, building upon a Phase 2a study by the NIH with 400 subjects. The Phase 2b study is in the process of enrolling 400 subjects to evaluate multiple dosing regimens. PaxVax expects the results in early 2019.

VLP vaccines are multi-protein structures that mimic the organization and conformation of naturally occurring viruses, but lack the viral genome. They are non-infectious. Additionally, the chikungunya VLP vaccine maintains natural epitopes to mimic natural infection.

The symptoms of chikungunya include headache, muscle pain, and skin rashes, with severe, often debilitating, joint pain that can persist for years, especially in adults and hence, represents a major public health issue. The virus spreads through mosquito bites and can often cause large outbreaks.

In 2016 there were approximately 60,000 cases of chikungunya across India, posing a large burden on the healthcare system.

Chikungunya virus is an arthropod-borne virus (arbovirus), closely related to other viruses in Africa, South America and Australia that cause similar symptoms. Chikungunya virus is a small, spherical RNA virus and a member of the Alphavirus genus in the family Togaviridae. The virus is vectored by the daytime-biting Aedes aegypti mosquito, which also transmits yellow fever, Zika and dengue viruses.

Chikungunya can also be transmitted by Aedes albopictus mosquitoes, a more cold-tolerant mosquito – this could result in the spread of chikungunya to more temperate areas of the world. Individuals who are at higher risk for more serious complications include infants, the elderly and those with chronic medical conditions.

There are currently no FDA approved vaccines for prevention of chikungunya and no specific treatments for the complications of the infection. Non-vaccine interventions to prevent infection are limited to using insect repellent, wearing long sleeves and pants and otherwise restricting exposure to vector mosquito.

"It is exciting to see this vaccine candidate moving forward with Fast Track designation as this is an extremely debilitating disease with the potential for causing serious long term sequelae," said Eva Harris, PhD Professor, Division of Infectious Diseases and Vaccinology and Director, Center for Global Public Health, University of California, Berkeley.

The FDA’s Fast Track program is designed to facilitate the development and expedite the review of therapies and vaccines for serious or life-threatening conditions to address unmet medical needs, with the intention to accelerate the availability of products.