18 April 2019 - - US-based biotechnology company Vaxart, Inc has started dosing subjects in the randomised cohort of the Phase 1b bivalent norovirus vaccine clinical trial, the company said.

The Vaxart bivalent norovirus vaccine consists of an oral norovirus GI.1 vaccine tablet and an oral norovirus GII.4 vaccine tablet administered concurrently.

The bivalent norovirus Phase 1b trial includes two stages, an open-label lead-in phase which was completed successfully earlier this month, and a randomised, double-blind, placebo-controlled phase which has now started. Both portions of the trial are designed to evaluate safety and immunogenicity.

The company expects to receive topline data from the trial in the second half of 2019.

Norovirus is recognised as the leading cause of acute gastroenteritis in the United States.

It is a common intestinal infection that typically lasts three to five days and is marked by diarrhea, vomiting, abdominal cramps, nausea and sometimes fever.

Symptoms can be more severe in older adults and young children and may lead to serious complications including death.

Norovirus causes frequent and widespread outbreaks in the military, food industry, travel industry, child care facilities, elderly homes and healthcare facilities.

The US Centers for Disease Control and Prevention estimates that norovirus causes approximately 19m to 21m illnesses in the United States each year, resulting in 56,000 to 71,000 hospitalizations and 570 to 800 deaths, mostly among young children and older adults.

In a recent study by Johns Hopkins University and the CDC, researchers estimated global economic impact of norovirus disease at USD 60bn, USD 34bn of which occurred in high income countries, including the United States, Europe and Japan.

Vaxart is a biotechnology company focused on developing oral recombinant protein vaccines based on its proprietary oral vaccine platform.

The company's vaccines are designed to generate broad and durable immune responses that protect against a range of infectious diseases and may also be useful for the treatment of chronic viral infections and cancer. Vaxart's vaccines are administered using a convenient room temperature-stable tablet, rather than by injection.

Vaxart said it believes that tableted vaccines are easier to distribute and administer than injectable vaccines and have the potential to significantly increase vaccination rates.

Vaxart's development programmes include oral tablet vaccines that are designed to protect against norovirus, seasonal influenza and respiratory syncytial virus, as well as a therapeutic vaccine for human papillomavirus.