June 2025
Herpes zoster virus vaccination: positive effects seen on CVD risk and dementia diagnoses
By Rebecca Jenkins
Immunisation against herpes zoster virus (HZV) may significantly reduce cardiovascular disease (CVD) risk for up to eight years, according to a large study of older adults.
Cardiovascular (CV) events were often recognised as potential complications of HZV infection, and although previous research had suggested that immunisation with a live HZV vaccine lowered CVD risk, these studies were limited by small sample sizes.
Writing in the European Heart Journal, researchers reported the results of a 12-year population-cohort study of the association between live HZV immunisation and CV outcomes in more than 1 million South Korean adults aged over 49 years.
Their analysis found vaccination was associated with lower rates of overall CV events (hazard ratio [HR], 0.77), including major CV events (HR, 0.74), heart failure (HR, 0.74), cerebrovascular disorders (HR, 0.76), ischaemic heart disease (HR, 0.78), thrombotic disorders (HR, 0.78) and dysrhythmia (HR, 0.79). The association lasted up to eight years, with the greatest risk reduction two to three years post-vaccination, the researchers reported.
The decrease in CVD risk was stronger for males, individuals aged under 60 years, those with unhealthy lifestyles, those from lower income and rural residents.
‘These findings suggest that live zoster vaccination may be beneficial as a public health strategy with potential implications for cardiovascular disease burden in the general population,’ the researchers concluded.
The study followed a recent analysis of Australian electronic health records suggesting that live HZV immunisation was protective against dementia in older adults.
Writing in JAMA, researchers compared dementia outcomes for adults who turned 80 years old after 1 November 2016 and were eligible for the Australian HZV immunisation program compared with people who turned 80 years old immediately before the eligibility cut-off date and were not invited for a free immunisation.
The researchers found that being eligible for the immunisation program decreased the risk of a new dementia diagnosis by 1.8 percentage points over 7.4 years of follow up.
The findings supported a similar study conducted in Wales, UK [See Journal Watch summary], the researchers noted, and suggested HZV vaccination was a ‘low-cost, high-reward intervention’ to reduce the burden of dementia.
Commenting on the studies, Professor Joseph Doyle, Head of Infectious Diseases Clinical Research at Burnet Institute, Melbourne, and Professor of Infectious Diseases at Monash University, said it was biologically plausible that the vaccination was having an impact on conditions such as dementia and CVD.
‘But the exact mechanism is unknown: it may be that preventing shingles infection itself or reducing inflammation can change dementia or CVD,’ he told Medicine Today.
‘It may be that the vaccine has other immune system effects that modify dementia or CVD; or it may also be that healthcare engagement among people who are vaccinated is different compared with those who aren’t vaccinated, and we know that engagement in care can have a connection with other health outcomes.’
Professor Doyle, who is also President of the Australasian Society for Infectious Diseases, noted that Australia approved and subsidised a newer recombinant HZV vaccine in 2023, and it was unclear if this vaccine would have the same associations with dementia and CVD as the older live vaccine.
‘The older (live) vaccine might affect the immune system differently from the newer Shingrix vaccine. Further studies are needed to find out whether these associations will be observed with the newer vaccine,’ Professor Doyle said.
‘Ideally, we would see pragmatic randomised trials conducted of people being vaccinated to help determine whether these associations could be causal.’
Eur Heart J 2025; doi: https://doi.org/10.1093/eurheartj/ehaf230.