Childhood immunization rates rebounding post-COVID era decline

By Jacqueline Howard | CNN

Millions of children around the world missed routine childhood vaccinations against diseases such as measles, diphtheria and tetanus during the Covid-19 pandemic, but new data suggests that this decline may be reversing.

Globally, 4 million more children worldwide received routine childhood immunizations last year than in the previous year, according to estimates released Monday by the United Nations Children’s Fund (UNICEF) and the World Health Organization (WHO).

“As opposed to what we were having over the last two years, which was a continued decline of coverage across several countries, this year we see an uptick,” said Dr. Ephrem Lemango, associate director of immunization at UNICEF.

The number of children who missed all of their routine immunizations fell from 18.1 million in 2021 to 14.3 million last year. Yet that number has not returned to or dropped below what was seen before the pandemic, as 12.9 million children missed all of their vaccinations in 2019.

Similarly, the number of children who missed out on one or more routine vaccinations fell from 24.4 million in 2021 to 20.5 million last year, the data showed. But that’s still more than the 18.4 million children who missed out on one or more vaccinations in 2019.

“Beneath the positive trend lies a grave warning,” UNICEF Executive Director Catherine Russell said in a news release Monday.

“Until more countries mend the gaps in routine immunization coverage, children everywhere will remain at risk of contracting and dying from diseases we can prevent. Viruses like measles do not recognize borders,” she said. “Efforts must urgently be strengthened to catch up children who missed their vaccination, while restoring and further improving immunization services from pre-pandemic levels.”

‘Severe and persistent inequities’

Scientists at UNICEF and WHO analyzed immunization trends and data, reported by 183 countries, for routine vaccinations against 13 diseases.

Among the 73 countries that reported substantial declines in childhood immunization coverage during the Covid-19 pandemic, 15 had returned to pre-pandemic vaccination levels, 24 are en route to recovery, and slightly fewer than half – 34 – have stayed stagnant or continued to see declines, according to the data.

UNICEF and WHO researchers measure a “substantial decline” as a drop of 5 percentage points or more in vaccination coverage compared by year. Smaller fluctuations in immunization coverage were considered not unusual before the pandemic.

“These data are encouraging, and a tribute to those who have worked so hard to restore life-saving immunization services after two years of sustained decline in immunization coverage,” WHO Director-General Tedros Adhanom Ghebreyesus said in the news release. “But global and regional averages don’t tell the whole story and mask severe and persistent inequities. When countries and regions lag, children pay the price.”

During the Covid-19 pandemic, “the moment we flagged the continued backsliding of immunization coverage, many countries went into efforts that include the intensification of their immunization work,” Lemango said. “This is a promising sign of recovery, and those countries that are doing well need to continue to do well.”

The improvements in childhood immunizations appear to be concentrated in a few countries; South Asia, which reported increases in immunization coverage even before the pandemic, was among regions with a more rapid and robust recovery. Eight countries overall accounted for 3.8 million children out of the 4 million more who were reached last year: India, Indonesia, Myanmar, Philippines, Brazil, Mexico, Pakistan and Tanzania, Lemango said.

“Despite such a promising sign, low-income countries and regions, like the African region, still have stagnated in terms of immunization coverage,” Lemango warned.

“High-income countries have been able to withstand the impact of the pandemic, so they have kept higher coverage. The upper middle-income countries, they went down a bit but they have largely recovered now. The lower middle-income countries, they also achieved promising recovery this year,” Lemango said. “So it is low-income countries, that are the ones that are heavily impacted by not only immunizations but also other health service challenges. They continue to trail back and require concerted support.”

Catching children up

The new data showed not only regional differences in the recovery of childhood immunization numbers but also differences based on which vaccine is being administered.

“For measles, which is another vaccine that we use to measure whether coverage is improving or not, the recovery is not as good as for the first DTP vaccine,” Lemango said.

The percentage of children who completed their first dose of the measles vaccine was 83% last year, compared with 81% in 2021, but those percentages are still much lower than the 86% achieved in 2019.

However, for the diphtheria, tetanus and pertussis vaccine or DTP, the percentage of children who completed their first dose was 89% in 2022, compared with 86% in 2021 and 90% in 2019.

And for the first time, HPV vaccination coverage surpassed pre-pandemic levels, according to the new data. HPV vaccination initiatives showed a coverage of the first dose of the vaccine of 21% in 2022, compared with 16% in 2021 and 19% in 2019. However, coverage is still far below the goal of 90% among 15-year-old girls, which health officials have set as a milestone to help eliminate cervical cancer by 2030.