Vaccinations: current trends and future perspectives

A review of global childhood immunisation shows that rates increased in 2022 over 2020, but have not yet reached pre-pandemic levels in many countries.

The impact of the COVID-19 pandemic on vaccination programmes

The Expanded Programme on Immunisation (EPI), initially established in 1974 by the World Health Organisation (WHO), aimed to ensure that every newborn child was given essential health vaccines such as those against diphtheria, tetanus, pertussis and other infectious diseases. Over the years, the EPI has included a wide range of vaccines.

In 2020, WHO adopted the Immunisation Agenda 2030 (IA2030), a global strategy that aims to ensure that everyone, everywhere and at any age, can fully benefit from vaccines. One of the main goals of IA2030 is to reduce the number of children who have not received the first dose of diphtheria-tetanus-pertussis-containing vaccine (DTPcv1) by 50 per cent by 2030.

However, the first steps in the implementation of the IA2030 programme were hampered by the COVID-19 pandemic, which led to a drop in vaccination coverage to its lowest level in a decade. This resulted in a 40% increase in the number of children without vaccine doses between 2019 and 2021. Even in 2022, the situation is still not fully resolved, with some persistent challenges.

Global child vaccination rates increase, but do not reach pre-pandemic levels

According to WHO and UNICEF estimates, global DTPcv1 vaccine coverage increased from 86% in 2021 to 89% in 2022, but is still below the 2019 level of 90%. The same trend is observed for DTPcv3, with an estimated coverage of 84% in 2022, up from 81% in 2021, but still below the 86% in 2019.

The situation is particularly worrying in Africa, where DTPcv1 and DTPcv3 coverage is stuck at 80% and 72%, respectively, well below 2019 levels. In contrast, in the European Region, DTPcv1 and DTPcv3 coverage remained consistently high, with values above 97% and 94%, respectively, in 2022.

Another critical aspect is the number of children without any vaccination, which decreased by 21% in 2022, from 18.1 million in 2021 to 14.3 million, but is still 11% higher than in 2019. The African region is the only one that reported an increase in the number of children without vaccine doses from 2021 to 2022. This shows that the recovery of vaccine coverage is uneven, with many challenges in low-income countries.

The situation is similar for measles vaccines, where global coverage of MCV1 (Measles-containing-vaccine first-dose) increased from 81% to 83% from 2021 to 2022 but remains below the 2019 level. At the same time, MCV1 saw a decrease in coverage in all regions except the Eastern Mediterranean, which returned to pre-pandemic levels in 2019.

Some other vaccines saw an increase in coverage, but remain below 2019 levels. However, some recent vaccine introductions have led to increased coverage in some regions. For example, the human papillomavirus (HPV) vaccine saw a 2% increase between 2019 and 2022, while the rotavirus vaccine increased from 40% to 51%.

One area of concern is vaccination dropout rates, which vary widely between low-income and high-income countries. For example, in 2022, the DTPcv1-to-DTPcv3 drop-out rate in low-income countries is 12%, while in high-income countries it is only 3%. This highlights inequalities in access to immunisation services.

Restoring confidence in vaccines

Despite the report's limitations, the authors conclude that while there are signs of recovery in global vaccination coverage in 2022, challenges for the future remain evident. It is essential to act quickly to ensure catch-up vaccination for children who are not fully vaccinated, to restore national vaccination coverage, and to strengthen immunisation programmes to meet future health emergencies.

Equity in access to vaccines remains a priority, especially in low-income countries and disadvantaged communities. WHO and UNICEF recommend that countries strengthen their immunisation programmes to ensure an effective response to events such as the COVID-19 pandemic. This requires strengthening the capacity of the health workforce, ensuring a reliable vaccine supply chain and rebuilding community trust and demand for vaccines.

Source
  1. Kaur G, Danovaro-Holliday MC, Mwinnyaa G, et al. Routine Vaccination Coverage — Worldwide, 2022. MMWR Morb Mortal Wkly Rep 2023;72:1155–1161. DOI: http://dx.doi.org/10.15585/mmwr.mm7243a1