Safety and Immunogenicity of a candidate ZIKV vaccine (ZIKA001)
Research type
Research Study
Full title
A phase I study to determine the safety and immunogenicity of the candidate Zika Virus (ZIKV) vaccine ChAdOx1 Zika in healthy adult volunteers given as a stand alone vaccine or co-administered with the Chikungunya Virus (CHIKV) candidate vaccine ChAdOx1 Chik.
IRAS ID
258895
Contact name
Adrian Hill
Contact email
Sponsor organisation
University of Oxford / Clinical Trials and Research Governance (CTRG)
Eudract number
2019-000075-16
Clinicaltrials.gov Identifier
Duration of Study in the UK
1 years, 9 months, 1 days
Research summary
Summary of Research
The purpose of this study is to test a new vaccine against the Zika Virus (ZIKV) in healthy volunteers given on its own and at the same time as another new vaccine against Chikungunya Virus (CHIKV).
Zika is a disease caused by ZIKV and can be transmitted to humans through a mosquito bite, from a pregnant woman to their unborn child and it can also be sexually transmitted. Symptoms of Zika infection include fever, headache, joint & muscle pains, tiredness and skin rashes, but most people won’t have any symptoms at all. The disease is now known to be associated with major neurological complications, especially in new-borns, with lifelong consequences. It became well-known after the World Health Organization (WHO) declared the Zika epidemic a Public Health Emergency of International Concern, following the rapid spread of the disease from Latin America in 2016 where several birth defects were associated with Zika infection. More than 85 countries have now reported Zika cases and the disease continues to spread globally. Zika is now part of the WHO list of priority diseases lists for accelerated vaccine research.
Chikungunya fever is a disease caused by CHIKV and it is transmitted to humans through a mosquito bite. It has been identified in over 100 countries in Asia, Africa, Europe, Oceania and the Americas. The disease typically consists of an acute illness characterised by fever, skin rash, muscle aches and severe joint pains (which are often incapacitating), lasting weeks to months or in rare cases, years. CHIKV is listed as priority virus by the UK Vaccine Network and the US National Institute of Allergy and Infectious Diseases. It has also been designated as a serious condition requiring action by the WHO to promote Research and Development to control future outbreaks.
There are currently no available specific treatments or licensed vaccines for any of these 2 diseases. The same type of mosquito is involved in the transmission of ZIKV and CHIKV and strategies tackling the control of the mosquito are extremely difficult to implement. The development of new vaccines is the most cost-effective way to fight Zika and Chikungunya
The study will enable us to assess the safety of new vaccines called ChAdOx1 Zika and ChAdOx1 Chik and the extent of their immune responses in healthy volunteers. We will do this by giving participants a single dose of either one (Zika) or both vaccines (Zika and Chikungunya), in addition to doing blood tests and collecting information about any symptoms that occur after vaccination. This is the first trial to use this Zika vaccine and the second study to use the Chikungunya vaccine in humans. We plan to recruit a maximum of 66 participants to be vaccinated, where half of them will receive the Zika vaccine only and the other half will receive both vaccines.
Healthy volunteers aged 18-50 will be recruited in Oxford and vaccinated at the Centre for Clinical Vaccinology and Tropical Medicine and will be followed for a period of 12 months. The study is funded by the UK Department of Health & Social Care and Innovate UK.Summary of Results
The purpose of this study was to test a new vaccine against Zika in healthy volunteers. The study enabled us to assess the safety of the new vaccine called ChAdOx1 Zika and the extent of the immune response in healthy volunteers.
ChAdOx1 Zika consists of a virus (ChAdOx1), which is a weakened version of a chimpanzee adenovirus that has been genetically altered so that it is impossible for it to grow in humans. To this virus we have added genes that make proteins from the Zika virus, which are essential to the structure of the virus. By vaccinating with ChAdOx1 Zika, we are hoping to make the body recognise and develop an immune response to these proteins that will neutralise the effects of the ZIKV in human cells and therefore prevent the infection responsible for the disease.
We tested the ChAdOx1 Zika vaccine at different doses (low, middle and high dose) in healthy adults in the Oxfordshire area in the UK. In this study, we have shown that the candidate ChAdOx1 Zika vaccine given as a single-dose was safe and well-tolerated in all 3 groups, although a higher reactogenicity profile was observed at the higher dose. No serious adverse reactions occurred during the follow-up period. Most adverse events reported were mild or moderate in severity and all resolved spontaneously. The profile of adverse events reported in this trial is similar to other ChAdOx1 vectored vaccines.
The vaccine was able to generate an immune response at all doses. Immune cells against the virus began to appear from 1 week following vaccination and lasted up to one year. Most of the volunteers also produced antibodies against the virus which reached their highest levels 1 to 2 months after vaccination.
The results of this first-in-human clinical trial support clinical development progression into larger trials in Zika endemic regions.REC name
South Central - Oxford A Research Ethics Committee
REC reference
19/SC/0074
Date of REC Opinion
15 Mar 2019
REC opinion
Favourable Opinion