It is \u201cnot possible to determine\u201d whether the shingles vaccination directly reduces the risk of dementia, the health and safety watchdog has said.<\/p>\n
There have been increased calls in recent weeks from opposition politicians, the Oireachtas health committee and representative organisations to make the shingles vaccine available for free under a public vaccination programme.<\/p>\n
Among the reasons behind the support for the availability of the vaccine was emerging evidence reporting a link between the shingles vaccination and lower dementia risk.<\/p>\n
The Health Information and Quality Authority<\/a> (Hiqa) on Wednesday published a scoping review examining whether there is evidence to support this link.<\/p>\n The review identified three considerations to help understand the area: the link between shingles and dementia, between shingles vaccination and dementia, and between adult vaccination generally and dementia. The review looked for studies to address each of these three topics. <\/p>\n Hiqa\u2019s review found some studies reported that shingles increases the risk of dementia, while others reported no clear link. <\/p>\n For the second question, the available studies reported a lower incidence of dementia in people with a history of shingles vaccination or in groups who were eligible for vaccination compared with those who were not.<\/p>\n While these studies can show an association, they cannot prove shingles vaccination reduces dementia risk, the body said.<\/p>\n For the third question, many reviews showed other adult vaccines, including influenza, are also linked with a lower risk of dementia. Again, they cannot prove vaccination alone resulted in lower risk, it added.<\/p>\n [\u00a0Increasing community care likely to put more pressure on services, State think tank saysOpens in new window<\/a>\u00a0]<\/p>\n In the absence of randomised clinical trials, Hiqa concluded \u201cit is not possible to determine whether shingles vaccination by itself directly reduces the risk of dementia\u201d.<\/p>\n \u201cThis is because the available evidence only looked at association and not causation. Other factors, including vaccinated individuals having healthier lifestyles and or lower levels of underlying risk, were also identified as potential explanations for the lower observed incidence of dementia,\u201d the watchdog said.<\/p>\n Dr Conor Teljeur, chief scientist at Hiqa, said dementia is a major public health challenge and \u201ceven modest reductions in risk could have meaningful benefits\u201d.<\/p>\n \u201cRecent studies report a protective association between vaccination and dementia. We need to understand the magnitude of any benefit of the shingles vaccine and the extent to which it applies independent of other vaccinations, such as for flu,\u201d he said.<\/p>\n In 2024, Hiqa recommended against providing the shingles vaccine for free for older adults, stating it was \u201cnot cost-effective\u201d.<\/p>\n In response to a parliamentary question in March, Minister for Health Jennifer Carroll MacNeill<\/a> said the introduction of the shingles vaccine to the schedule is being \u201cactively considered for a cohort of immunocompromised individuals\u201d.<\/p>\n