New shingles vaccine shows dementia protection promise, but South Africa faces affordability hurdles

Melanie Verwoerd remembers the moment shingles arrived in her life with absolute clarity. A band of blisters twenty centimeters wide wrapped around her back and under her arm, stretching across her stomach. The pain was unlike anything she had endured before—and she had endured operations, injuries, the accumulated aches of a full life. For months, the former MP and South African ambassador to Ireland could barely function. When the blisters finally faded, she made a decision: this would not happen again.

She asked her doctor about Shingrix, a new vaccine against shingles that had begun circulating in conversations about aging and brain health. The pitch was compelling. Yes, it would prevent shingles—a disease caused by the chickenpox virus that lies dormant in the nervous system and strikes roughly one in three people at some point in their lives. But studies suggested something more: the vaccine might also reduce the risk of dementia by as much as a quarter. For Verwoerd, the calculus seemed obvious. She wanted the shot. South Africa, however, did not yet have it.

Shingrix arrived in South Africa at the end of June 2026, nearly a decade after its approval in the United States. The price was R2,783 per injection. Two injections were required, spaced two to six months apart. The total cost: R5,566—a sum that places the vaccine far beyond the reach of most South Africans and even many with private health insurance. This timing matters. South Africa has never been enthusiastic about adult vaccination. Only about a third of adults receive the annual flu shot. Less than four percent took the previous shingles vaccine, a live vaccine called Zostavax that had been available since 2011.

The old vaccine carried a fundamental limitation: because it contained a weakened but living virus, it could not be given to people whose immune systems were already compromised. This excluded people undergoing chemotherapy, those being treated for autoimmune diseases like lupus, and people living with HIV—precisely the populations at highest risk for shingles. For HIV-positive individuals, even those whose virus was well-controlled by medication, the risk of shingles was three to five times higher than in the general population. Zostavax also simply did not work very well. It prevented shingles in 64 percent of people aged 60 to 69, but that protection collapsed to just 18 percent in people over 80, the very group most vulnerable to the serious complications that shingles can trigger. India Butler, a geriatrician at Wits Donald Gordon Medical Centre in Johannesburg, described the impact with clinical precision: shingles could transform a robust person into a frail one. "It's terrible," she said.

Shingrix changes this picture entirely. The new vaccine is more than 90 percent effective in people over 50, and that protection holds steady even in the oldest populations. It is an inactivated vaccine—no living virus—which means it can be safely given to immunocompromised patients who desperately need it. Butler's assessment was unambiguous: "It's a brilliant, amazing vaccine. I can't wait to give it to my mother."

But the dementia question has captured public imagination in ways the basic efficacy numbers have not. In July 2024, evidence emerged that shingles vaccination was associated with lower dementia risk. The finding sparked urgent conversations in the United States, with patients asking neurologists about using shingles shots as a dementia prevention tool. Ireland's health authorities cited the evidence when advocating for adding the vaccine to the national adult immunization program. Verwoerd, who eventually traveled overseas to get vaccinated, said the dementia findings had made her want the vaccine even before she developed shingles. "I think it should be free," she said. If the protection held up, vaccinating older adults seemed like a bargain compared to the astronomical costs of dementia care.

Yet the evidence, while suggestive, remains incomplete. Studies from the UK and US, which have vaccinated large populations, do show an association between shingles vaccination and lower dementia risk. One Welsh study exploited a quirk in the rollout schedule: people born just days apart had vastly different chances of receiving the vaccine, creating two otherwise similar groups. The vaccinated group developed dementia at about 20 percent lower rates over seven years. Another analysis compared the older Zostavax to the newer Shingrix, finding that people who received Shingrix delayed dementia onset by an average of five months. The mechanism is plausible. Shingles can cause vasculitis—inflammation of blood vessels in the brain—leading to small blockages that accumulate silently over time. Allison Glass, a clinical virologist at Lancet Laboratories in Johannesburg, found the logic compelling: "I can imagine how that could lead to dementia over time."

But none of these studies prove causation. The gold standard—a randomized controlled trial where one group receives the vaccine and another receives a placebo—has not been conducted. And the size of the effect, while real, is modest. A 24 percent reduction in dementia risk translates to roughly two fewer cases per 1,000 people over three years. That small number, multiplied across an aging population, becomes significant. South Africa's dementia cases are projected to nearly triple by 2050 as people live longer and conditions like diabetes and hypertension—both risk factors for cognitive decline—become more prevalent.

Whether any of this will influence South Africa's decisions about Shingrix remains uncertain. Discovery Health, the country's largest medical aid, said its coverage decisions would be "guided by clinical evidence, regulatory requirements and affordability." The government has not yet received a recommendation from its national advisory group on immunization. GSK says it is open to discussions with the health department, but no tender has been issued and no timeline exists. A deeper problem shadows these conversations: shingles is not a reportable disease in South Africa, so no one actually knows how many cases occur or how much burden the disease creates. Glass noted the irony: "Certainly with our large immunosuppressed population, we've got even more of a burden than most other countries. But there's no data on what that incidence is, because nobody records that." South Africa's health system, Butler observed, moves from crisis to crisis, and preventative medicine opportunities vanish in the urgency of immediate needs. The flu vaccine, she pointed out, offers a strikingly similar list of benefits—lower dementia risk, reduced mortality, fewer complications from frailty—and it is free. Yet uptake remains stubbornly low. The question now is whether the promise of a sharper mind in old age will prove more persuasive than decades of evidence about preventing the flu.