Global Immunization Coverage Lacking Since COVID-19 Pandemic, Especially in Children

New data from the World Health Organization (WHO) and UNICEF have indicated large setbacks in global immunization coverage with vaccine uptake not yet returning to 2019 levels, leaving many, including millions of children, un- and under-vaccinated.^1,2

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There were 2.7 million additional children that were un- and under-vaccinated compared to pre-pandemic levels in 2019, according to the data. There have been difficulties in vaccinating children against diphtheria, tetanus, and pertussis (DTP) and measles.²

The year 2023 saw 14.5 million infants who did not receive an initial dose of DTP vaccine, an increase from 13.9 million in 2022. The percentage of children who received 3 doses of DTP vaccine stalled at 84%; over 6 million children did not complete their third dose, greatly decreasing protection in infancy and early childhood.²

Measles vaccination rates in children have also stalled. Only 83% of children worldwide received their first dose of the measles vaccine in 2023. There was a slight increase in uptake of the second measles dose, with 74% of children receiving it.²

Overall, 35 million children were left with no or only partial protection against measles. Approximately 22.2 million children missed their routine first dose, which was far from the level of 19.3 million in 2019.^1,2

Taken together, these data fall short of the 95% coverage that WHO recommends to “prevent outbreaks, avert unnecessary disease and deaths, and achieve measles elimination goals.”²

Jeffery Goad, PharmD, MPH, a professor of pharmacy at Chapman University School of Pharmacy, told the American Journal of Managed Care that the community had hoped to see a return to pre-pandemic immunization levels as 2022 and 2023 progressed.³

Instead, “what we’ve seen is actually a leveling off of the immunization rates in 2023,” Goad explained. In addition to the leveling of vaccine uptake, the population of developing countries continues to increase, which can amplify the problem and lead to a growing number of un-vaccinated individuals.³

Low vaccine coverage has driven measles outbreaks across the world, with 103 countries—home to about three-quarters of the globe’s infants—suffering an outbreak over the course of the last 5 years. Contrastingly, in 91 countries that have strong measles vaccine coverage, outbreaks were not observed.²

The difference in immunization coverage between countries becomes starker when analyzing DTP vaccine uptake. Of the 21 million children who either did not receive an initial dose of DTP vaccine or are partially vaccinated, around 60% of them live in 10 countries, mostly in Africa and Asia.¹

Tedros Adhanom Ghebreyesus, the director-general of WHO, called measles outbreaks “the canary in the coal mine, exposing and exploiting gaps in immunization and hitting the most vulnerable first.”²

Vaccination early in childhood is “globally cost effective,” according to Goad. Low immunization rates lead to higher rates of mortality and higher health care costs across the board. These can compound on low-income countries, which are already struggling to afford immunizations and necessities.³

“It really is one of the most cost effective, safe strategies we have to protect infants,” Goad said.³

Despite the unfortunate topline data, there were some positives gleaned from the data. In Africa, the region “defied the odds” and increased routine immunization coverage, with 1.5 million more children vaccinated with DPT than in 2019. Additionally, there was a decline in zero-dose children from 7.3 million in 2022 to 6.7 million in 2023.⁴

In another positive development, human papillomavirus vaccine coverage increased, with the share of adolescent girls across the world who received at least 1 dose rising from 20% in 2022 to 27% in 2023.²

“This progress, despite the challenges of a growing child population, reflects the growing national prioritization and focus on resilient immunization programs,” Kate O’Brien, director of the Department of Immunization, Vaccines, and Biologicals at WHO, said in a statement.⁴

To increase immunization rates, Goad called for an optimizing of the vaccine distribution infrastructure, with a strong emphasis on pharmacy-based immunization. Goad notes that pharmacists and pharmacies are trusted sources of information, and that increasing the supply of vaccines in these locations can help to close the immunization gap.³

Goad cautioned that pharmacists and vaccinators must “know where your patients fall in their belief system” regarding receiving a vaccine and take the right approach to convincing those who are hesitant. Recounting that vaccine hesitancy has been present since the smallpox immunization was introduced—though now any falsehoods can be spread in seconds—he says that patients need to “trust the message.”³

“We have to make sure that we’re communicating authentically, and in a way that people can understand the science that we’re trying to present,” Goad explained. “Sometimes, we get too lost in our own facts and figures and people lose the message.”³

References

1. World Health Organization. Immunization coverage fact sheet. News Release. Released July 15, 2024. Accessed July 30, 2024. https://www.who.int/news-room/fact-sheets/detail/immunization-coverage

2. World Health Organization, UNICEF. Global childhood immunization levels stalled in 2023, leaving many without life-saving protection. Joint News Release. Released July 15, 2024. Accessed July 30, 2024. https://www.who.int/news/item/15-07-2024-global-childhood-immunization-levels-stalled-in-2023-leaving-many-without-life-saving-protection

3. Shaw, Maggie L. Bridging the vaccination gap: insights on global immunization challenges. American Journal of Managed Care: Managed Care Cast. Released July 30, 2024. Accessed July 30, 2024. https://www.ajmc.com/view/bridging-the-vaccination-gap-insights-on-global-immunization-challenges

4. World Health Organization. Message by the Director of the Department of Immunization, Vaccines, and Biologicals at WHO – June 2024. News Release. Released July 16, 2024. Accessed July 30, 2024. https://www.who.int/news/item/16-07-2024-message-by-the-director-of-the-department-of-immunization--vaccines-and-biologicals-at-who---june-2024