Beyond Shingles: What One Vaccine Study Tells Us About Ageing, HIV, and Research Equity

For people living with HIV, the landscape of health has shifted dramatically – and for the better. But with success comes new challenges.

Thanks to antiretroviral therapy, HIV is no longer an automatic death sentence. In countries like Botswana, where treatment is widely available and most people achieve viral suppression, those living with HIV are growing older and living fuller lives. Yet, reaching old age opens a new chapter. Suddenly, things like heart disease, cancer, metabolic problems, and memory loss become more common – and they’re showing up earlier than in people without HIV.

This means we can’t just focus on keeping the virus in check. We need to ask bigger, tougher questions: How do we prevent illness before it starts? What can we do about inflammation? How do we help people with HIV live not just longer, but healthier lives?

One unexpected clue comes from an unlikely place: the shingles vaccine.

A Surprising Signal from a Shingles Vaccine Study

A large study looked at adults who got the shingles (herpes zoster) vaccine and found something remarkable: those who were vaccinated had lower risks of heart attacks, strokes, dementia, and even death from any cause compared to those who didn’t get the shot.

https://www.idsociety.org/news--publications-new/articles/2025/shingles-vaccine-lowers-risk-of-dementia-major-cardiovascular-events/?utm_source='chatgpt.com

This research wasn’t looking for heart disease or dementia. Those results came as a surprise, popping up from real-world data. But the evidence was convincing enough to make people pay attention:

• Fewer heart attacks and strokes
• Lower rates of vascular dementia
• Reduced overall mortality

For people who are already vulnerable to diseases linked to inflammation, especially those living with HIV, this raises an intriguing question: Could stopping the virus from flaring up help prevent heart problems and memory loss down the road?

Why This Matters for People Living with HIV

Even when the virus is under control, HIV keeps the immune system on high alert. This constant, low-level inflammation can quietly cause:

• Heart disease at younger ages
• Metabolic complications
• Problems with memory and thinking

Botswana and many African nations have done an incredible job helping people survive HIV. Now, the challenge is helping those same people age well. Non-communicable diseases are becoming more common, but efforts to prevent them are often scattered and disconnected.

If a routine vaccine for adults could also protect against heart disease and dementia, it could change everything,  not just for HIV care, but for anyone facing the challenges of ageing.

But before policies can shift, the science needs to catch up.

The Limits of Observational Studies

Observational studies are a powerful tool. They let scientists see patterns in large groups of people in real life and sometimes uncover surprises nobody expected. But they aren’t perfect.

People who get vaccinated often have more resources, better access to doctors, more health knowledge, or fewer health problems. This “healthy user bias” makes it tough to say for sure that the vaccine itself is what’s making the difference.

In simple terms: Just because things are connected doesn’t mean one causes the other.

Observational studies are great for raising new questions. To get real answers, we need randomised controlled trials (RCTs)!!!  the gold standard in research.

Why RCTs Are Difficult in High-Income Countries

In wealthier countries, the shingles vaccine is already recommended for older adults and people with weaker immune systems, including those with HIV. Here’s the catch: once a vaccine is part of standard care, it’s no longer ethical to give some people a placebo or make them wait for the real thing. That limits research options.

Researchers have to get creative: using delayed vaccination or phased rollout studies. These methods help, but they’re slower and don’t always give clear answers on long-term impacts like heart disease or dementia.

But that’s not the situation everywhere.

An Opportunity in Countries Where the Vaccine Is Not Standard of Care

In countries like Botswana, shingles vaccination isn’t part of routine adult care. The vaccine is expensive and hard to access. But this isn’t about withholding care,  it’s about genuine uncertainty. Scientists call this equipoise, meaning there’s still a real question to answer. This is an ethical chance to run the kind of rigorous trials that could help not just Botswana, but people everywhere.

How an Observational Signal Can Become an RCT

In places where the shingles vaccine isn’t the norm, there are several ways to design ethical RCTs:

1. Classic Vaccine-Versus-Placebo RCT

Volunteers can be randomly assigned to receive either the vaccine or a placebo, then followed to see who develops heart problems, dementia, or dies over time.

This offers the strongest evidence and is ethically sound when the vaccine isn’t standard care.

2. Pragmatic or Cluster RCTs

Instead of randomising individuals, entire clinics or communities can be assigned to either start offering the vaccine or stick to current practice. This reflects how health decisions happen in real life, making the results more relevant to policymakers.

3. Stepped-Wedge Rollout Trials

Here, every site eventually gets the vaccine, but the timing is randomised. This fits well with national plans that roll out new vaccines step by step, and ensures fairness.

4. Enriching for Higher-Risk Groups

To make trials more practical, researchers can focus on those who have the most to gain:

• Older adults
• People living with HIV
• Those with metabolic syndrome, high blood pressure, or chronic kidney problems

Botswana’s strong HIV care system and ability to follow patients over time make it an ideal place for these studies.

Why This Matters for Global Health Equity

Too often, countries with fewer resources do the heavy lifting for research, but don’t get to shape the global conversation. Trials in places where the vaccine isn’t standard can:

• Change policy based on new evidence
• Build local research skills and capacity
• Make sure findings are useful for real communities, not just ideal scenarios

Most importantly, ethical research must guarantee that if a trial proves a benefit, those who took part – and their countries – aren’t left behind. Everyone deserves access to the best care.

What This Could Mean for Policy and HIV Care

If future studies prove that the shingles vaccine really does protect against heart events or dementia, the impact could be huge:

• Adult vaccines could be seen as a way to prevent heart and metabolic disease
• HIV care for older adults could include vaccine protection
• Infectious disease prevention could be better connected with strategies for non-communicable diseases

For Botswana and similar countries, this could mean expanding adult vaccine programs based on local evidence, not just on what works elsewhere.

From Signal to Science to Systems Change

The story of the shingles vaccine shows how science often moves in unexpected directions. A shot meant to prevent a painful rash might end up saving hearts and minds too.

But spotting a promising trend is just the first step.

Countries where shingles vaccination isn’t yet routine have a rare chance,  not to be passive participants, but to take the lead. By turning observations into well-designed trials, they can help set new global standards and show what healthy ageing really means for people living with HIV.

In a world where living long with HIV is now possible, it’s time to think bigger about prevention, and about what it means to thrive as we age.