Fewer Infants in the Americas, Africa are Getting First-Year Vaccines

Nearly 14 million children around the globe did not receive their first dose of diphtheria and tetanus toxoids and pertussis-containing vaccine (DTP) last year, ending a decade of stable “zero-dose children” rates in regions of the Americas, Africa, and Western Pacific nations.

In a new article published to the US Centers for Disease Control and Prevention (CDC) Morbidity and Mortality Weekly Report, a team of US investigators reported that most particularly in low-income countries, they observed a rising rate of zero-dose children versus previous decades in 2019 alone.

Though the rate of first DTP vaccines in these countries—as well as rates of surviving children—remain improved from troublesome averages reported in the 2000s, the investigators observed continued gaps in overall improvement from a decades-old global vaccination strategy.

The Expanded Program on Immunization was set in 1974, with an agenda of worldwide vaccine coverage for infants on 4 recommended vaccines: the bacillus Calmette-Guerin vaccine (BCG), DTP, the polio vaccine, and measles-containing vaccine (MCV). They have since added prophylaxes for rubella, pneumococci, hepatitis B, human papillovirus (HBV), and more for first-year infants.

This assessment, by Anna N. Chard, PhD, of the CDC Epidemic Intelligence Service, and colleagues, assessed annual country-by-country infant vaccination estimates from the World Health Organization (WHO) and United Nations Children’s Fund (UNICEF) to observe recent trends in coverage and associated mortality by regions of the world.

The report serves as part of the Immunization Agenda 2030, from the World Health Assembly in 2020.

Overall, Chard and colleagues observed substantial progress in infant vaccination worldwide since the mid-1970s. That said, dosing for standard vaccines is recently lagged across differing regions.

Though 90% of infants worldwide have received their first DTP dose (DTP1) in 2019, just 81% of infants in Africa had received it. The third DTP dose (DTP3) was also notably low among African infants (74%), as well as American infants (84%).

Globally, zero-dose children had decreased significantly from the 2000s (21.4 million) to the 2010s (14.9 million; 30.3% decrease), but only slightly decreased from then until 2019 (13.8 million; 7.3% decrease). The rate of zero-dose children actually increased by 0.4 percentage points, to 4.0%, in 2019—and remained the same among high-income countries, at 0.3%.

After reporting an approximate zero-dose children rate of 500,000 in both the 2000s and 2010s, the Americas reported 1.5 million in 2019—a rate of 11%.

Alarmingly, Africa reported 6.8 million (49%) zero-dose children in 2019—a steady rise from the 2000s (38%) and the 2010s (41%).

Interestingly, investigators observed that a greater proportion of zero-dose children have lived in middle-class countries since 2010, during which time many low-income countries had advanced to middle-income status and became less eligible for immunization program funding despite lacking ideal infrastructure during the advancement.

“Identifying demographic, social, and systemic factors inhibiting vaccine delivery and developing locally tailored, context-specific strategies to increase access, availability, and demand for immunization services will be important for reaching zero-dose children,” they wrote.

Given the disruption to routine immunization programs brought on by the coronavirus 2019 (COVID-19) pandemic, Chard and colleagues stressed for the implementation of catch-up strategies that can compensate for anticipated greater loss in global infant vaccination in 2020.

“Addressing immunization gaps created by the pandemic will require monitoring immunization program setbacks, implementing catch-up vaccination policies and strategies, and expanding and intensifying routine immunization services,” they stressed.