Zika viral vector vaccine
The Zika virus (ZIKV) outbreak in South America escalated to a global health crisis, mainly due to an association found between ZIKV infection and neurologic diseases in developing foetuses, such as microcephaly and Guillain-Barre syndrome; as well as with the ability of ZIKV to be passed by sexual transmission. The virus has now spread to more than 45 countries, 25 of which reported severe ZIKV-associated disease. As a result, there is an urgent need to prevent men and importantly women both before and during pregnancy from being infected by ZIKV.
Oxford researchers have developed a Zika viral-vectored vaccine carrying a sequence encoding a Zika structural antigen. The sequence is a consensus derived from the bioinformatic analysis of the African and Asian lineages of the virus. has been filed for the technology
Zika virus (ZIKV) is a mosquito-borne virus that belongs to the family Flaviviridae. Initially detected in Africa, it has spread through Polynesia and is now spreading rapidly throughout the Americas and Asia. Since the outbreak of ZIKV disease in Brazil in 2015, ZIKV infection has been linked to neurologic conditions in developing foetuses, such as microcephaly and Guillain-Barre syndrome. Importantly, only 2 out of 5 people exhibit signs and symptoms of ZIKV infection, and person to person transmission makes ZIKV a very challenging flavivirus to tackle.
The virus has now spread to more than 45 countries, 25 of which reported severe ZIKV-associated disease. An estimated 100 million people in the Americas are predicted to be at risk of acquiring ZIKV. According to a recent WHO report, ZIKV remains an enduring public health challenge requiring intense action. There is an urgent need to protect women, either before or during pregnancy, from infection by the virus. Currently, there is no vaccine for ZIKV or effective treatment for the disease.
Designing an effective vaccine is highly challenging. When introduced with a viral vector, the antigen should be produced and secreted at an amount that is sufficient to stimulate robust antibody and cytotoxic responses. Ideally, the antigen should also induce an immune response against many (or all) strains of the virus.
Zika viral vector vaccine
Oxford researchers have developed a Zika vaccine based on a viral vector which contains a sequence encoding a ZIKV structural antigen. Using a bioinformatic approach, the antigen consensus sequence that has been carefully designed using the published ZIKV genetic sequences. It is highly similar – at least 99% – to the strains causing the epidemics in the Americas but also matches closely with the African genotype. The ZIKV antigen has been designed to allow high titers of antibody production after a single and non-adjuvanted vaccination dose. Therefore, the vaccine should suitable to be used in many countries affected by various strains of ZIKV.
The vaccine induced a substantial immune response against ZIKV after a single dose with high levels of ZIKV antibodies up to 9 months after a single ChAdOx1 Zika vaccination, in mice.
Available for licensing
A patent has been filed for this technology. Oxford University Innovation is seeking a development partner to license this technology and support its future developments.
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