LONDON—British biopharmaceutical company Prokarium has announced it is developing What it hopes will be the world’s first orally administered vaccine designed to protect against both insect-borne (antibody-mediated) and sexually transmitted (mucosal and cell-mediated) Zika virus. Prokarium specializes in using synthetic biology in its product development, which will be essential in the advancement of the new vaccine. The goal is to produce an oral vaccine that is easy to administer, highly effective and stable for long periods in storage.
Zika has emerged as a critical threat to public health. The World Health Organization (WHO) declared a Public Health Emergency of International Concern because of clusters of microcephaly and other neurological disorders in some areas affected by Zika. While many people who contract Zika may be asymptomatic, scientists have found a strong correlation between women infected with the Zika virus and severe birth defects, including microcephaly and other fetal brain abnormalities. Once thought to be transmitted only through the bite of an infected Aedes species mosquito, evidence now shows that the virus can be spread through sexual contact, raising the stakes across the globe to find an effective vaccine.
“A vaccine that protects against both transmission routes is the only way to offer the maximum safeguard and stop the spread,” according to Prokarium sources.
Prokarium is best known for its Vaxonella platform. This proprietary synthetic biology application enables vaccines to be taken orally, and then to be made from inside the body’s own immune cells, triggering all arms of immunity with little or no side effects and at lower cost than injectable vaccines.
“We use a safe bacterium, which is swallowed and then enters into the immune cells of the gut lining to produce vaccine there. The oral delivery means that we kick-start mucosal immunity, the body’s first defense against infection in the gut, nose or the vaginal tract. The production of vaccine from within immune cells means that our approach causes few or zero side effects, while crucially initiating cellular immunity, which is very important for combatting viruses like Zika,” says Prokarium’s CEO Ted Fjällman.
The Zika project is a one-year program beginning in October 2016. The initial test will be to determine if the vaccine can protect against vaginal Zika challenge. If the vaccine proves capable, a Phase 1 clinical trial will begin in 2018.
Oral vaccines provide a particular benefit when addressing such widespread diseases as Zika. Oral vaccines have increased thermostability compared to injectables, remaining stable at 40°C for 14 weeks and boasting a shelf life of more than three years at 4°C.
“A [key] challenge is to distribute the drugs or vaccines to the population quickly, and here oral, thermostable vaccines would be ideal, as they could be distributed in normal trucks and even be self-administered in emergencies,” says Fjällman.
The Zika vaccine project is being funded by the UK Department of Health, the UK Vaccine Network and the Mexican government, supporting Prokarium as it works in partnership with Public Health England. It is part of a £2-million funding package to develop three vaccines to fight plague (anti-bioterror), bacterial diarrhea and Zika. Prokarium is also developing oral vaccines against chlamydia, Clostridium difficile and exacerbations of COPD and asthma.
Fjällman commented, “We’re delighted to be recognized by some of the brightest minds in vaccine research and to receive contracts from both the UK and Mexican governments. It gives us another chance to demonstrate the wide applicability of our synthetic biology platform Vaxonella, which is already being tested ... for the development of a chlamydia vaccine.”