While reported measles cases have fallen compared to previous years, progress toward measles elimination continues to decline and the risk of outbreaks is mounting, according to a new report from the World Health Organization (WHO) and US Centers for Disease Control and Prevention (CDC).
During 2020, more than 22 million infants missed their first dose of measles vaccine – three million more than in 2019, marking the largest increase in two decades and creating dangerous conditions for outbreaks to occur. Compared with the previous year, reported measles cases decreased by more than 80% in 2020.
However, measles surveillance also deteriorated with the lowest number of specimens sent for laboratory testing in over a decade. Weak measles monitoring, testing and reporting for measles jeopardise countries’ ability to prevent outbreaks of this highly infectious disease. Major measles outbreaks occurred in 26 countries and accounted for 84% of all reported cases in 2020.
“Large numbers of unvaccinated children, outbreaks of measles, and disease detection and diagnostics diverted to support Covid-19 responses are factors that increase the likelihood of measles-related deaths and serious complications in children,” said Kevin Cain, CDC’s Global Immunisation Director. “We must act now to strengthen disease surveillance systems and close immunity gaps, before travel and trade return to pre-pandemic levels, to prevent deadly measles outbreaks and mitigate the risk of other vaccine-preventable diseases.”
The ability of countries to ensure children receive both recommended doses of measles vaccine is a key indicator of global progress toward measles elimination and capacity to prevent the spread of the virus. First-dose coverage fell in 2020, and only 70% of children received their second dose measles vaccine, well below the 95% coverage needed to protect communities from the spread of the measles virus.
Adding to the worsening of immunity gaps worldwide, 24 measles vaccination campaigns in 23 countries, originally planned for 2020, were postponed because of the Covid-19 pandemic – leaving more than 93 million people at risk for the disease. These supplemental campaigns are needed where people have missed out on measles-containing vaccines through routine immunisation programmes.
“While reported measles cases dropped in 2020, evidence suggests we are likely seeing the calm before the storm as the risk of outbreaks continues to grow around the world,” said Dr Kate O’Brien, Director of WHO’s Department of Immunization, Vaccines and Biologicals. “It’s critical that countries vaccinate as quickly as possible against Covid-19, but this requires new resources so that it does not come at the cost of essential immunisation programmes. Routine immunisation must be protected and strengthened; otherwise, we risk trading one deadly disease for another.”
The Covid-19 pandemic caused significant disruptions to immunisation services and changes in health-seeking behaviors in many parts of the world. While the measures used to mitigate Covid-19 – masking, handwashing, distancing – also reduce the spread of the measles virus, countries and global health partners must prioritise finding and vaccinating children against measles to reduce the risk of explosive outbreaks and preventable deaths from this disease.
Image credit: Charles Deluvio