The Challenge

Zika virus is a mosquito-borne flavivirus first identified in monkeys in Uganda in 1947. The first largescale outbreak of the disease caused by a Zika infection was reported from the Island of Yap (Federated States of Micronesia) in 2007. Sexual transmission of Zika virus has also been confirmed and other modes of transmission are currently being investigated. The incubation period of Zika virus disease is not well defined but is likely to be a few days – similar to other arbovirus infections such as dengue fever. A diagnosis of Zika virus infection can only be confirmed through laboratory tests on blood or other body fluids, such as urine, saliva or semen.

In 2015, an association between Zika virus infection, Guillain-Barré syndrome and microcephaly was reported and was subsequently confirmed. Some evidence exists that other neurological disorders are also linked with Zika infection.

There is currently no vaccine available.

OraPro-Zika™ – an oral vaccine for Zika virus

Using our unique OraPro™ technology, we can deliver reproducible doses of infectious non-replicating viral vectors to the luminal surface of the intestinal mucosa. Once the epithelial lining cells are infected, they can produce proteins which can find their way to the circulatory system. Once there, these proteins are recognised as foreign and can raise an immune response. Experimental investigations using exemplar antigens have shown that a humoral response is raised after oral administration of OraPro-Zika™.


iosBio’s approach offers several obvious advantages over the current vaccination development programmes:

  • Easy self-administration via a tablet
  • Long shelf-life at ambient temperature
  • Two Zika antigens presented to provide broad immunity that is equivalent to prior exposure and natural immunity to whole Zika virus


Part of the OraPro-Zika development program has been funded by InnovateUK and the current technology is now being used to develop an orally administered COVID-19 vaccine.