Uganda’s booster strategy could expand childhood and adolescent protection, but the budget bill rises quickly
Routine infant vaccination has already pushed diphtheria, tetanus, and pertussis into a narrower clinical space than they once occupied. Yet protection does not hold forever. As antibody levels wane across childhood and adolescence, the question is no longer whether boosters can extend immunity, but whether health systems can absorb the cost of delivering them at scale.
This modeling study examined the health and budget impact of introducing three diphtheria-tetanus-pertussis-containing vaccine booster doses in Uganda, spanning ages from 12 months to 15 years. The analysis used an integrated multi-disease epidemiological-economic model to compare booster introduction against no booster strategy and against introduction of an early childhood booster at 18 months alone. The design focused on projected cases averted, deaths averted, shifts in population immunity, and the government vaccination cost required to deliver each planned dose.
Immunity gaps widen when protection is left to fade
Under modelled assumptions, introducing all three booster doses is projected to raise the proportion of the population protected against symptomatic diphtheria 2.2-fold and tetanus infection 2.8-fold among Ugandans under 15 years of age by 2039, compared with no DTPCV boosters. Those gains reflect a central feature of vaccine-preventable disease control: infant series can suppress early transmission, but without reinforcement, immunity thins out before children age into the window where exposure can resume through household, community, or school contact.
Protection against diphtheria and tetanus is not just a serologic abstraction. For tetanus, where environmental exposure persists even in highly vaccinated populations, waning immunity can leave older children and adolescents with a biologic vulnerability that routine infancy schedules do not fully eliminate. For diphtheria, booster-induced immunity helps tighten the population firewall against symptomatic infection, especially where sustained coverage is needed to prevent sporadic outbreaks from spreading through partially immune communities.
A booster schedule changes the shape of that immunity curve.
Three boosters outperformed one in both health gain and cost per dose
The comparison with the early childhood booster alone is where the model becomes especially consequential for policy. Simultaneous introduction of all three DTPCV boosters is projected to avert 3.2 times the number of tetanus cases over 15 years, at 2.4 times the incremental cost. In other words, the broader booster package does not simply spend more to buy marginal benefit; it delivers a substantially larger health return, even though the total budget requirement rises.
The projected government vaccination cost per planned dose was USD 0.58 for simultaneous introduction of all three boosters, compared with USD 0.68 for the early childhood booster alone. That difference matters because unit cost can determine whether a vaccination policy is feasible for a national program that must balance procurement, delivery, and competing public health demands. A lower cost per planned dose does not erase the larger aggregate spend, but it does suggest a more efficient delivery profile than a narrower booster plan.
The average annual incremental cost of all three booster doses was estimated at USD 2.79 million. For a national immunization budget, that is not a trivial line item. It represents a recurring expenditure rather than a one-time investment, and recurring costs are the ones that strain programs when revenue is tight, donor support shifts, or other health priorities compete for the same funds.
The economic case is stronger than the affordability case
This is where public health modeling becomes most useful: it separates biological value from fiscal capacity. On the health side, the projected gains are substantial. On the budget side, the picture is more constrained. The model indicates that simultaneous introduction of all three booster doses in Uganda offers the greatest health gains and a lower government vaccination cost per planned dose than the early childhood booster alone, yet it may still pose affordability challenges for government planners.
That tension is familiar in immunization policy. A strategy can be technically efficient and still be hard to finance. Booster schedules also add delivery complexity, because every additional age checkpoint requires attention to procurement planning, cold chain management, service delivery platforms, and follow-up systems that keep adolescents from slipping out of reach after the infant period ends.
For Uganda, the implication is straightforward even if the financing path is not: the most complete booster approach yields the deepest immunity gains, but the ministry must decide whether the annual fiscal commitment can be absorbed without displacing other essential services.
Modeling data point toward a policy trade-off, not a clinical shortcut
Because this was an integrated modelling analysis rather than a prospective clinical trial, the results depend on the assumptions built into the model and the quality of the input data. The study used publicly accessible epidemiological, demographic, vaccination, and economic sources, with model input parameters and assumptions laid out in the appendix. Ethical approval was not required because the work relied on aggregate secondary data and did not involve individual participants.
The policy question therefore turns on realism as much as on efficacy. If programmatic delivery can sustain age-based booster administration across early childhood, school age, and adolescence, the model suggests clear gains in population immunity and tetanus prevention. If financing cannot support the full package, decision-makers may still favor partial introduction, staged roll-out, or alternative prioritization within the national schedule.
The report’s central message is not that boosters are optional. It is that booster timing and sequence shape both the epidemiology of protection and the fiscal demands placed on Uganda’s immunization program. The broader schedule appears to deliver more health for each planned dose, but the annual budget impact remains large enough to force a difficult choice between ideal coverage and what the system can afford year after year.