Pertussis in Latin America: Resurgence, Immunization Gaps, and Opportunities for Action

Dr. María Luisa Ávila Agüero. Pediatric Infectious Diseases Specialist, former Minister of Health of Costa Rica, and Past President of the Latin American Society for Pediatric Infectious Diseases (SLIPE). She is also a distinguished member of the National Academy of Sciences and the National Academy of Medicine of Costa Rica.

Pertussis has accompanied humanity for centuries, often hidden behind a persistent cough that rarely draws the attention of clinicians or surveillance systems. Before the COVID-19 pandemic, the cyclical patterns characteristic of Bordetella pertussis were well known, with peaks every three to five years and a disproportionate burden in infants. However, during the initial years of the pandemic, this natural cycle appeared to halt. Physical distancing, widespread mask use, and decreased mobility sharply reduced the transmission of multiple respiratory pathogens, including pertussis. For the first time in decades, the continent reported exceptionally low figures: 3,283 cases in 2022, the lowest number recorded in the Region of the Americas in recent years.

But this decline was illusory. Once mitigation measures were relaxed, the scenario shifted rapidly. In 2023, cases increased to 4,139, and in 2024, the region reported 43,751 cases. Provisional data from the Pan American Health Organization (PAHO) indicate 18,595 cases and 128 deaths during the first seven months of 2025 across nine countries. This abrupt rise underscores that the disease never disappeared—it merely lost its capacity to circulate temporarily. The fuel behind this resurgence had been accumulating silently for years: widening immunization gaps, delays in childhood vaccination schedules, declining vaccination during pregnancy, and weakened surveillance systems.

The setback in coverage is particularly striking: Latin America went from being a global leader in childhood immunization with 93% DTP3 coverage in 2012 to only 75% in 2021, the greatest decline documented in any region during that period. By 2024, the region had accumulated the equivalent of 1.5 million zero-dose children. Behind these percentages lie communities where vaccination became inaccessible, pregnant women who could not receive Tdap, health systems unable to recover delayed schedules after the pandemic, and clinical services that failed to suspect pertussis in adolescents and adults—fueling invisible chains of transmission.

Surveillance represents another critical weakness. The region continues to use heterogeneous case definitions, with varying levels of access to PCR, limited clinical suspicion in older age groups, and uneven laboratory capacity across countries. As a result, underreporting is significant, and the true magnitude of the epidemic far exceeds the numbers captured in official records. This underestimation not only hinders epidemiologic understanding but also delays essential programmatic decisions. In parallel, another threat emerged: the detection of macrolide-resistant pertussis strains in several countries, a worrisome signal that reinforces the need for prevention rather than relying on increasingly complex diagnosis and treatment.

In this context, acellular pertussis–containing combination vaccines have become a fundamental tool. Their lower reactogenicity, greater acceptability among caregivers and health professionals, and reduced number of injections per visit improve adherence and timeliness of childhood immunization. Countries that have implemented these vaccines report better tolerance, improved maternal and infant acceptance, and a positive impact on coverage recovery. Moreover, their use in boosters for adolescents, adults, and pregnant women is essential for a life-course immunization strategy that reduces community transmission and protects young infants—the group at highest risk.

Today, the region faces a decisive moment. Rising case numbers, the reemergence of severe complications, and the circulation of resistant strains make it clear that we cannot continue doing the same and expect different results. Pertussis is a vaccine-preventable disease; addressing it requires collective will and coordinated regional action.

Achieving meaningful progress demands four urgent and structural transformations:

1. Unifying the pertussis case definition across the region, using harmonized clinical and laboratory criteria to enable comparability and improve epidemiologic accuracy.  
2. Strengthening diagnostic capacity, ensuring broad access to PCR and enhancing clinical training to increase suspicion of pertussis at all ages.  
3. Sustainably increasing vaccination coverage, particularly through the use of acellular pertussis–containing combination vaccines, which enhance acceptability among infants, children, adolescents, adults, and pregnant women.  
4. Closing territorial and social gaps, ensuring that no child remains unprotected due to limited access, logistical barriers, or misinformation.

Pertussis reminds us that the region’s immunization systems possess strengths, but also profound vulnerabilities. The pandemic demonstrated that population behaviors can change dramatically in a short time; now, that capacity must be redirected toward rebuilding trust in vaccines, modernizing surveillance, and protecting the youngest members of society. This is not only about recovering coverage—it is about preventing history from repeating itself. Every infant hospitalized with a vaccine-preventable disease represents a chain of preventable failures. Latin America has the tools, the science, and the experience. What is needed now is decisive, cohesive, forward-looking action.

This is the moment—because if we continue doing the same, the results will not change. And the region cannot afford to repeat this cycle.

REFERENCES

1. Pan American Health Organization (PAHO). Epidemiological Alert: Increased pertussis (whooping cough) in the Americas Region – 10 June 2025.
2. UNICEF. Latin America and the Caribbean records world’s biggest drop in childhood vaccination over past decade. 2023 Apr 20.
3. Gentile A, Castellano VE, Ulloa-Gutierrez R, Dueñas L, Torres JP, Izquierdo G, et al. Pertussis Vaccination During Pregnancy: Regional Situation and Impact. Pediatr Infect Dis J. 2025;44(2S):S80-S84.
4. Ulloa-Gutierrez R, Hozbor D, Avila-Aguero ML, Echániz-Aviles G, Gentile A, Torres Torretti JP, et al. Country-Specific Data and Priorities for Pertussis in Latin America. Open Forum Infect Dis. 2025;12(5):ofaf154.
5. Avila-Aguero ML, Betancourt-Cravioto M, Trejo Varon R, et al. Impact of acellular immunization against pertussis; comparative experience of four countries in North, Central and South America. Expert Rev Vaccines. 2025;24(1):834-839.
6. Pan American Health Organization (PAHO). Detection of antibiotic-resistant pertussis strains in the Americas – News Release. 26 August 2025.
7. Avila-Aguero ML, Brenes-Chacon H, Melgar M, Becerra-Posada F, Chacon-Cruz E, Gentile A, et al. Zero-dose children in Latin America: analysis of the problem and possible solutions. F1000Res. 2025;13:1060.