By Sola Ogundipe

Measles vaccination coverage has steadily declined, according to the World Health Organisation, WHO.

 In 2021, nearly 40 million children missed a measles vaccine dose; 25 million children missed their first dose of the measles vaccine and an additional 14.7 million children missed their second dose, according to a joint publication by the WHO and the United States Centres for Disease Control and Prevention (CDC).

The decline is a significant setback in global progress toward achieving and maintaining measles elimination and leaves millions of children susceptible to infection.

In 2021, the WHO argues, there were an estimated 9 million cases and 128,000 deaths from measles worldwide. At least 22 countries experienced large and disruptive outbreaks.

Declines in vaccine coverage weakened measles surveillance and continued interruptions and delays in immunisation activities due to COVID-19, as well as persistent large outbreaks in 2022, mean that measles is an imminent threat in every region of the world.

In the views of the WHO Director-General, Dr Tedros Adhanom Ghebreyesus, “The paradox of the pandemic is that while vaccines against COVID-19 were developed in record time and deployed in the largest vaccination campaign in history, routine immunisation programmes were badly disrupted, and millions of kids missed out on life-saving vaccinations against deadly diseases like measles.

“Getting immunization programmes back on track is absolutely critical. Behind every statistic in this report is a child at risk of a preventable disease.”

The situation is grave: measles is one of the most contagious human viruses but is almost entirely preventable through vaccination.

Coverage of 95 percent or greater of 2 doses of measles-containing vaccine is needed to create herd immunity in order to protect communities and achieve and maintain measles elimination.

 The world is well under that, with only 81 percent of children receiving their first measles-containing vaccine dose, and only 71 percent of children receiving their second measles-containing vaccine dose. These are the lowest global coverage rates of the first dose of measles vaccination since 2008, although the coverage varies by country.

The WHO notes that urgent global action is needed now that measles is a threat everywhere, as the virus can quickly spread to multiple communities and across international borders.

No WHO region has achieved and sustained measles elimination. Since 2016, 10 countries that had previously eliminated measles experienced outbreaks and reestablished transmission.

In the views of CDC Director Dr. Rochelle P. Walensky, “The record number of children under-immunised and susceptible to measles shows the profound damage immunisation systems have sustained during the COVID-19 pandemic. 

Measles outbreaks illustrate weaknesses in immunisation programmes, but public health officials can use outbreak response to identify communities at risk, understand causes of under-vaccination, and help deliver locally tailored solutions to ensure vaccinations are available to all.” 

In 2021, nearly 61 million measles vaccine doses were postponed or missed due to COVID-19-related delays in immunisation campaigns in 18 countries.

“Delays increase risk of measles outbreaks, so the time for public health officials to accelerate vaccination efforts and strengthen surveillance is now.”

The CDC and WHO urge coordinated and collaborative action from all partners at global, regional, national, and local levels to prioritise efforts to find and immunise all unprotected children, including those who were missed during the last two years.

Measles outbreaks illustrate weaknesses in immunisation programs and other essential health services. To mitigate the risk of outbreaks, countries and global stakeholders must invest in robust surveillance systems.

Under the Immunisation Agenda 2030 global immunisation strategy, global immunisation partners remain committed to supporting investments in strengthening surveillance as a means to detect outbreaks quickly, respond with urgency, and immunise all children who are not yet protected from vaccine-preventable diseases.