A new randomised trial from Jinja Regional Referral Hospital found that 20mg of daily oral zinc cut overall infection rates by 38 per cent and severe bacterial infections by two-thirds in young children with sickle-cell anaemia — a result that directly contradicts an earlier trial’s finding of no benefit at half the dose, and that researchers say could translate into a genuinely low-cost intervention across a disease that kills disproportionately in sub-Saharan Africa.
A randomised, placebo-controlled clinical trial conducted at Jinja Regional Referral Hospital in Uganda has found that daily zinc supplementation at 20 milligrammes meaningfully reduces the rate of infections in young children with sickle-cell anaemia (SCA), the most severe form of sickle-cell disease. The trial, known as ZIPS-2 (“Zinc for Infection Prevention in Sickle Cell Anemia”), was published in JAMA and reported on 19 August 2026. Researchers randomly assigned 100 children aged 12 to 59 months with confirmed SCA — specifically the HbSS genotype, sickle-cell disease’s most severe form — to receive either oral zinc sulfate at 20mg daily or an identical-appearing placebo, for six months. Children receiving zinc experienced 38 per cent fewer infections overall, and a two-thirds reduction in severe bacterial infections specifically, compared with the placebo group.
Why the dose matters: a direct reversal of an earlier finding
What makes this result scientifically significant, rather than simply another positive supplementation trial, is its direct relationship to an earlier, larger study that found the opposite result at a different dose. A predecessor trial — ZIPS-1, also conducted in Uganda, registered on ClinicalTrials.gov and published following completion — randomised 252 Ugandan children with SCA to 10mg of daily oral zinc sulfate or placebo for twelve months, and found no significant difference in infection incidence between the two groups (282 versus 270 severe or invasive infections per 100 person-years, a difference that did not reach statistical significance). That earlier null result was itself a genuine scientific disappointment, given that zinc deficiency is well documented as common among children with SCA and that zinc supplementation had previously shown benefit in older adolescents and adults with the condition; ZIPS-1’s failure to replicate that benefit in young children raised real questions about whether the mechanism held at all in this age group, or whether the trial’s specific dose and population had simply been the wrong test of it.
ZIPS-2’s investigators, evidently informed by that earlier result, tested whether a higher dose — 20mg daily rather than 10mg — might succeed where the lower dose had not, in a comparable population at the same trial site. The positive result this time round is a meaningful piece of evidence that the original biological hypothesis — that correcting zinc deficiency reduces infection risk in children with SCA — was broadly correct, but that ZIPS-1’s dose had simply been insufficient to produce a detectable clinical effect in this age group and population, a dose-response relationship rather than an absence of any underlying effect. This kind of direct, same-population, dose-comparison result is considerably more persuasive than a single positive trial in isolation would be, because it offers a coherent explanation — insufficient dosing — for why the earlier, larger trial failed to find what this one did, rather than leaving the discrepancy as an unexplained anomaly between two studies.
The population most affected
Sickle-cell anaemia disproportionately affects children in sub-Saharan Africa: more than 240,000 of the roughly 300,000 infants born globally each year with the condition are born in the region, and infection is a leading cause of illness and death among affected children there, driven partly by the immune dysfunction that accompanies the disease and partly by the additional burden of zinc deficiency, which researchers note is common in this population and impairs immune function independently. The ZIPS-2 authors reported that zinc deficiency rates in children with SCA in North America — 44 to 57 per cent, according to figures cited alongside the new trial — are comparable to those documented in Uganda, a finding the researchers suggest indicates that similar trials of higher-dose zinc supplementation could be warranted in higher-income countries as well, rather than the intervention being relevant only in the low-resource settings where it was tested.
Why a positive result on an inexpensive intervention matters disproportionately
Zinc sulfate is inexpensive, shelf-stable, orally administered and has a well-established general safety profile, which makes a genuinely positive trial result for it unusually consequential from a public-health-implementation standpoint compared with an equally positive result for a costlier, harder-to-distribute intervention. Interventions of this kind — cheap, simple, deliverable through existing primary healthcare infrastructure without cold-chain requirements or specialist administration — are precisely the category most likely to translate from a successful clinical trial into a genuinely scaled public-health programme in the resource-constrained settings where sickle-cell disease’s burden falls heaviest. That said, the trial’s sample size (100 children) is modest by the standards of clinical research intended to change practice guidelines, and its authors are reported to have described the 20mg dose as a “safe and inexpensive way to prevent infections” in careful, appropriately hedged terms rather than as a settled recommendation — language that reflects the genuine need for confirmatory research in larger and more geographically diverse populations before zinc supplementation guidelines for children with SCA would typically be revised.
Why it matters
This result is a rare instance in nutrition and supplementation research of a well-designed follow-up trial directly resolving an ambiguity left by an earlier study, rather than simply adding another data point to an already-crowded and often-contradictory supplementation literature. For a disease that kills a substantial share of affected African children before the age of five, largely from infections that a low-cost, orally administered mineral supplement may meaningfully reduce, a credible positive result — properly caveated by its modest sample size and its status as a single confirmatory trial rather than a settled guideline change — represents a genuinely promising, low-cost public-health lead. For India specifically, which carries a substantial sickle-cell disease burden of its own, particularly among tribal populations in central India where the National Sickle Cell Anaemia Elimination Mission (launched in 2023) has been an active priority, a validated, inexpensive dosing regimen from a comparable low-resource clinical setting is the kind of evidence that could plausibly inform future Indian public-health guidance, pending the further confirmatory research the trial’s own authors say is warranted.
Rithvisha Kiran
## Key facts
– Trial: ZIPS-2, a randomised, placebo-controlled trial at Jinja Regional Referral Hospital, Uganda; 100 children aged 12–59 months with confirmed HbSS-genotype sickle-cell anaemia
– Intervention: 20mg oral zinc sulfate daily versus placebo, for six months
– Result: 38% reduction in overall infections; two-thirds reduction in severe bacterial infections, in the zinc group
– Directly contradicts the earlier ZIPS-1 trial (252 children, 10mg dose, 12 months), which found no significant infection-rate difference — interpreted as a dose-response effect rather than a contradiction of the underlying hypothesis
– Published in JAMA; reported 19 August 2026
