The most updated version of the herpes zoster vaccine, marketed as Shingrix, has shown an unforeseen benefit: a reduction in the risks of developing heart diseases. This finding was revealed by a recent study that analyzed data from over 70,000 individuals.
Although the study does not establish a cause-and-effect relationship, the article, published in the journal Nature Medicine, presents data that may point to other beneficial effects of the vaccine beyond viral protection. There is growing evidence linking this immunizer to a lower risk of Alzheimer's and other forms of dementia.
Herpes zoster is a condition caused by varicella-zoster virus (VZV), the same agent that causes chickenpox. After a bout of chickenpox, the virus remains latent but can reactivate in older people or those with a compromised immune system, resulting in skin lesions, intense pain, and other clinical signs, commonly known as 'shingles.' A vaccine is available, recommended for those over 50 or for those in risk groups.
Previous research had already suggested that individuals vaccinated against herpes zoster showed lower rates of heart problems. However, these analyses were limited because they compared vaccinated versus unvaccinated individuals, which introduces bias, given that those who choose immunization tend to be more health-conscious and have a healthier lifestyle.
Analysis based on vaccine transition
The new study used a distinct methodology, made possible by a type of 'natural experiment.' In 2017, the United States discontinued the Zostavax vaccine, which was made with a weakened virus, migrating to the use of the Shingrix immunizer, which contains a fraction of the virus and has higher efficacy.
Scientists compared the health records of people who received the previous version of the vaccine before 2018 with those who were injected with the most recent formulation. Each group consisted of approximately 36,000 people aged 60 or older.
The results indicated that patients who received Shingrix lived, on average, 9% longer without developing cardiovascular diseases over a seven-year period, compared to those who took Zostavax. This suggests that the newer vaccine version may delay or prevent the onset of cardiac complications. Furthermore, the immunizer was correlated with a 12% lower risk of stroke (CVA) in men.
In Brazil, the Shingrix vaccine against herpes zoster is only available through the private network, with costs that can reach R$ 2,000 (considering the two necessary doses). The exact reason for this correlation is still unknown; one possibility raised is that the vaccine may reduce inflammation in both blood vessels and tissues. However, more studies are needed, including to verify whether this association occurs in younger age groups.
The Ministry of Health considered including the immunizer in the National Immunization Program (PNI), which would imply free provision by Public Health (SUS), but this proposal was subsequently rejected.