The effect of zoster vaccination on cardiovascular and neurodegenerative disease

A first infection with the varicella zoster virus manifests as chickenpox, after which the virus remains “hibernated” in nerve cells in the body and can break out occasionally to cause shingles. The virus has recently been implicated in a variety of health outcomes related to inflammation of blood vessels, such as heart attacks and strokes. Understanding whether this virus really is involved in the causal pathway that leads to such health outcomes could be very useful to our understanding of these diseases, and ultimately how to treat and prevent them. In addition, because there is an effective vaccine to reduce the chance of getting shingles, it is important to find out if the vaccine can prevent some of these adverse health outcomes. If so, promoting uptake of the vaccine, and potentially providing it already at younger ages or as additional “booster shots”, could be an effective tool for preventing these adverse health outcomes. We plan to take advantage of the way in which the shingles vaccine was rolled out in Scotland to help us control for the fact that usually those who get vaccinated are different in various health-related characteristics compared to those who do not get vaccinated. Using our approach, we will be able to contribute to the research evidence on the varicella zoster virus in a new and important way because we will be able to provide estimates of the shingles vaccine’s effects that are less vulnerable to bias than most other existing studies as we will be in a position to more convincingly compare population groups that are truly comparable to each other. In addition, we will be able to provide a rigorous evaluation of the effect of vaccine on shingles prevention when the vaccine is rolled out in the routine health system as opposed to in a highly controlled research setting.