Childhood immunization begins recovery after COVID-19 backslide

July 18, 2023
New WHO and UNICEF data show promising signs of immunization services rebounding in some countries.

Global immunization services reached 4 million more children in 2022 compared to the previous year, as countries stepped up efforts to address backsliding in immunization caused by the COVID-19 pandemic.

According to data published by the World Health Organization (WHO) and UNICEF, in 2022, 20.5 million children missed out on one or more vaccines delivered through routine immunization services, compared to 24.4 million children in 2021. In spite of this improvement, the number remains higher than the 18.4 million children who missed out in 2019 before pandemic-related disruptions, underscoring the need for ongoing catch-up, recovery and system strengthening efforts.

The vaccine against diphtheria, tetanus and pertussis (DTP) is used as the global marker for immunization coverage. Of the 20.5 million children who missed out on one or more doses of their DTP vaccines in 2022, 14.3 million did not receive a single dose, so-called zero-dose children. The figure represents an improvement from the 18.1 million zero-dose children in 2021 but remains higher than the 12.9 million children in 2019.

Of the 73 countries that recorded substantial declines in coverage during the pandemic, 15 recovered to pre-pandemic levels, 24 are on route to recovery and, most concerningly, 34 have stagnated or continued declining.

Vaccination against measles - one of the most infectious pathogens - has not recovered as well as other vaccines, putting an additional 35.2 million children at risk of measles infection. First dose measles coverage increased to 83% in 2022 from 81% in 2021 but remained lower than the 86% achieved in 2019. As a result, last year, 21.9 million children missed the routine measles vaccination in their first year of life – 2.7 million more than in 2019 – while an additional 13.3 million did not receive their second dose, placing children in under-vaccinated communities at risk of outbreaks.

Countries with steady, sustained coverage in the years before the pandemic have been better able to stabilize immunization services since, the data indicates.

DTP3 vaccine coverage in the 57 lower-income countries supported by Gavi, the Vaccine Alliance increased to 81% in 2022 – a considerable increase from 78% in 2021 – with the number of zero-dose children who receive no basic vaccines also dropping by 2 million in these countries. However, the increase in DTP3 coverage in Gavi-implementing countries was concentrated in lower-middle income countries, with low-income countries not yet increasing coverage – indicating the work remaining to help the most vulnerable health systems rebuild.

HPV vaccination coverage surpassed pre-pandemic levels. HPV vaccination programs that began pre-pandemic reached the same number of girls in 2022 than 2019. However, coverage in 2019 was well below the 90% target, and this has remained true in 2022, with mean coverages in HPV programs reaching 67% in high income countries and 55% in low- and middle-income countries. The newly launched HPV revitalization, led by the Gavi Alliance, aims to strengthen existing program delivery and facilitate more introductions.

WHO release