Geneva - More than 22 million infants have missed their first dose of measles vaccine in 2020 due to the Covid-19 pandemic - marking the largest increase in two decades and creating dangerous conditions for outbreaks to occur, according to a joint report from the World Health Organization (WHO) and the US Centers for Disease Control and Prevention (CDC) on Thursday.
The number of unvaccinated children in 2020 is 3 million more than in 2019 - marking the largest increase in two decades.
The estimated number of measles cases in 2020 was 7.5 million globally, with major outbreaks occurring in 26 countries. However, compared with 2019, the reported measles cases decreased by more than 80 per cent in 2020.
This could also be attributed to decrease in measles surveillance with the lowest number of specimens sent for laboratory testing in over a decade, the report said.
Poor measles monitoring, testing and reporting can jeopardise countries' ability to prevent outbreaks of this highly infectious disease.
"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, MD, CDC's Global Immunisation Director, in a statement.
"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," added Dr Kate O'Brien, Director of WHO's Department of Immunisation, Vaccines and Biologicals.
In 2020, the first-dose coverage fell, and only 70 percent of children received their second dose measles vaccine, well below the 95 percent 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.
"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," O'Brien noted.
Measles is one of the world's most contagious human viruses but is almost entirely preventable through vaccination. In the last 20 years, the measles vaccine is estimated to have averted more than 30 million deaths globally.
Estimated deaths from measles dropped from around 1,070,000 in 2000 to 60,700 in 2020.
Measles transmission within communities is not only a clear indicator of poor measles vaccination coverage, but also a known marker, or 'tracer,' that vital health services are not reaching populations most at risk.