NHS HIGHLAND: Research finds possible added incentive for taking up vaccination offer
Infectious diseases have always been important in people’s lives. Despite the development of antibiotics and rising living standards, we remain vulnerable to infections both new and old.
The Covid pandemic demonstrated the effects that infections can have on the world but there are impacts from infections that go more widely.
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Stomach ulcers provide a good example of the unexpected effects of infections. For decades it was thought that things like stress and excess acid were the main causes of stomach ulcers and infections were not considered.
However, some innovative and dedicated research led by two Australians showed that a newly discovered type of bacterium, called Helicobacter pylori, was a principal cause of stomach ulcers. This discovery revolutionised the effective treatment of stomach ulcers with antibiotics and won the Australians a Nobel prize.
Sometimes it is the reaction of the body to an infection that causes more harm than the infection itself. This happened to some people during pandemics of Covid and influenza.
Several serious conditions that we would not readily associate with an infectious origin are caused by the reaction of our immune system against our own bodies, known as autoimmunity. One of these is type 1 diabetes.
We do not definitely know that an infection is involved in autoimmunity, but it is quite possible that a virus acts as a trigger for an autoimmune disease in combination with other factors such as our inherited genes. We cannot be sure what, if any, specific viruses may act as triggers, but it does open the possibility of new ways to prevent and treat these diseases.
Given this background, I was fascinated to see news reports of research from a population in Wales that suggests that people who have been vaccinated with the shingles vaccine are less likely to develop dementia.
The virus that causes shingles is the same virus that causes chickenpox. Chickenpox is a very infectious virus, and most people are infected as young children. Following chickenpox infection, the virus can remain in our bodies in nerve cells and then will sometimes become active again often many years later, producing the painful rash of shingles.
Having the shingles vaccine reduces the chance that this will happen. Whether viruses contribute to the development of dementia is still uncertain. It is possible that the chickenpox virus has an effect directly or indirectly through another virus or a reaction of our immune system. Perhaps the vaccine has another effect. It is far too early to be sure.
I hope that all those invited for shingles vaccination will take up the offer, in order to reduce the chance of developing debilitating and painful shingles. Perhaps the possibility that this could also help reduce the risk of dementia will be an added incentive.
Dr Tim Allison is NHS Highland’s director of public health and policy.
