Phase 1b/2 study of a Modified Vaccinia Ankara vectored Zika Vaccine to assess safety in previously flavivirus exposed healthy adults.

寨卡病毒是一种常见的蚊子传播的病毒感染，通常会引起轻度发烧，但在孕妇中可能会损害未出生的婴儿并导致重大残疾。儿童出生时头部较小，智力和身体受损。近年来，这在南美洲和中美洲一直是一个特别的问题，但寨卡病毒感染也存在于热带地区的许多国家。寨卡病毒感染没有治疗方法，因此需要通过接种疫苗进行预防。然而，任何疫苗都应该安全地用于年轻和孕妇，以保护母亲和儿童免受伤害。我们通过将寨卡病毒遗传密码片段整合到天花疫苗中，设计并生产了寨卡疫苗。选择天花疫苗是因为它以前曾被用于制造其他疫苗，它有很强的安全记录，这种特殊的疫苗在注射人体时不能复制自己，因此在怀孕期间使用应该是安全的。MVA不属于任何人，因此疫苗生产应该相对便宜，疫苗的价格适合低收入和中等收入国家。寨卡疫苗中包含了几种成分，可以让免疫系统产生多种免疫反应，我们相信这种疫苗将提供更好的保护性，在世界上寨卡病毒流行的地区效果更好。我们的疫苗被称为MVAZIKAB。它在用于人类之前已经完成了实验室研究，迄今为止已被证明可以产生强烈的免疫反应，保护小鼠免受寨卡病毒感染。它已经被制造出来，所以现在适合用于人类。我们将在2022年初为首批健康志愿者进行免疫接种。如果这些初步研究证明是安全的，我们将扩大研究范围，增加健康志愿者的数量，以更好地了解免疫反应。然而，重要的是，我们将把疫苗给少数健康的志愿者，他们曾接触过类似寨卡病毒的其他感染。如果我们要在世界上寨卡流行的地区使用这种疫苗，这将是一种常见的情况，确保这一群体的安全性和免疫反应将为南美洲流行地区的进一步研究提供保证。

Zika virus is a common mosquito spread viral infection that usually causes mild fever but in pregnant women may damage the unborn baby and cause major disability. Children are born with small heads and suffer intellectual and physical impairment. This has been a particular problem in south and central America in recent years but zika infection is also present in many countries in tropical regions. No treatment for zika virus infection is available thus prevention by vaccination is desirable. However any vaccine should be safe to use in young and pregnant women to safeguard the mother and child from harm.We have designed and produced a zika vaccine by incorporating bits of the zika virus genetic code in a smallpox vaccine. The smallpox vaccine has been chosen as it has been used to make other vaccines previously, it has a strong track record of safety and this particular vaccine cannot make copies of itself when injected in a human and therefore should to be safe when used in pregnancy. MVA is not owned by anyone, therefore the vaccine manufacture should prove relatively inexpensive and the vaccine made available at a price suitable for low and middle income countries.The bits of the zika vaccine that have been included incorporate several components that allow the immune system to generate multiple immune responses, which we believe will provide a more protective vaccine and work better in areas of the world where zika circulates.Our vaccine is known as MVAZIKAB. It has completed laboratory studies prior to use in humans and to date has been shown to produce a strong immune response that protects against zika infection in mice. It has been manufactured so it is now suitable for use in humans. We will undertake the immunisation of the first healthy volunteers in early 2022\. If as we expect these initial studies prove safe we will extend the study to increase the number of healthy volunteers to get a better understanding of immune response. However and importantly, we will give the vaccine to a small number of healthy volunteers who have been exposed to other infections similar to zika. This will be a common occurrence if we are to use this vaccine in areas of the world where zika circulates and ensuring safety and immune response in this group will provide reassurance for further studies in endemic regions of south America.