A 79% rise in the reported measles cases in the first two months of 2022, compared to the same period last year, has raised concerns over the possibility of an outbreak that could affect millions of children this year. 

Pandemic-related disruptions, increasing inequalities in access to vaccines, and the diversion of resources from routine immunization have created the ‘perfect storm’ of conditions for a measles outbreak, WHO and the United Nations Children’s Fund (UNICEF) warned on Wednesday. Children are not only at risk of being infected with measles –a disease which is preventable through vaccination– but also other vaccine-preventable diseases. 

Risks of a bigger outbreaks have also been heightened by the relaxation of social distancing norms in communities around the world, along with the mass displacement of people, including many children, due to conflicts and crises in countries ranging from Ukraine, Ethiopia, Somalia and Afghanistan.  

Some 17,338 measles cases were reported worldwide in January and February 2022, compared to 9,665 during the same period last year, said WHO and UNICEF. The possibility of underreporting looms large as the pandemic has disrupted global surveillance of cases and vaccinations. 

23 million children have missed out on basic vaccines  

There is rising concern over children becoming more susceptible to other vaccine-preventable diseases too.  Some 23 million children have missed out on basic childhood vaccines through routine health services in 2020. This is the highest number since 2009 and 3.7 million more than in 2019.

As of April 2022, 57 vaccine-preventable disease campaigns in 43 countries that were scheduled to take place since the start of the pandemic are still postponed, impacting 203 million people, most of whom are children, WHO and UNICEF said. Of these, 19 are measles campaigns, which puts an additional 73 million children at risk of measles due to missed vaccinations. In Ukraine, the measles catch-up campaign of 2019 was interrupted firstly by the COVID-19 pandemic and more recently, by Russia’s recent invasion.

“It is encouraging that people in many communities are beginning to feel protected enough from COVID-19 to return to more social activities. But doing so in places where children are not receiving routine vaccination creates the perfect storm for the spread of a disease like measles,” said Catherine Russell, UNICEF Executive Director.

According to Dr Tedros Adhanom Ghebreyesus, Director-General of the WHO, the disruptions caused by the COVID-19 pandemic in immunization services for many other diseases will be felt for decades to come. “Now is the moment to get essential immunization back on track and launch catch-up campaigns so that everybody can have access to these life-saving vaccines.”

Humanitarian crises disrupting vaccination programs 

In  2017-2019, there were over 115,000 cases of measles and 41 deaths in Ukraine which was the highest incidence in Europe.

Along with Ukraine, humanitarian crises in Ethiopia and Afghanistan are seriously disrupting vaccination programmes for measles and other diseases. 

Three of the five countries globally with the highest measles cases so far this year – Somalia, Ethiopia and Nigeria – are in Africa. Afghanistan and Yemen are the other two countries whose caseload of measles puts them in the top five countries burdened with measles. 

Because measles is one of the world’s most highly contagious infectious diseases, it has a high threshhold for herd immunity, meaning that vaccination rates need to be particularly high to prevent outbreaks. “When vaccination drops, measles is typically the first childhood disease to have an outbreak.” Andrew Noymer of the University of California was quoted as saying in an article on Ethiopia’s measles outbreak, published in The Lancet Infectious Diseases’ May 2022 edition. 

In the first three months of 2022, there were 2,156 confirmed cases of measles and 2,755 suspected cases, WHO’s Regional Office for Africa has reported. The vaccination status of 40% of the suspected cases was not known. The measles outbreak in Ethiopia comes at a time when the country is facing a complex humanitarian and armed conflict that has led to a high number of refugees and internally displaced people.  Other measles outbreaks are occurring in Chad, Congo, the Democratic Republic of Congo, Guinea, Liberia, Mali. Mozambique, Niger and Nigeria, Sierra Leone, South Sudan, and Togo, with thousands of confirmed cases and tens of thousands of suspected cases across the continent, WHO said. 

Measles also is known to weaken a child’s immune system and makes them susceptible to other infectious diseases like pneumonia and diarrhoea, the WHO and UNICEF said. At population level, vaccine coverage at or above 95%, with two doses of the safe and effective measles vaccine, can protect children against measles outbreaks.

Image Credits: UNICEF, UNICEF , UNICEF/WHO.