The number of total reported cases rose by 18% over the same period, accounting for approximately 9 million cases and 136,000 deaths globally, mostly among children. This information comes from a new report by the World Health Organization (WHO), published in partnership with the US Centers for Disease Control and Prevention (CDC).
More Measles Outbreaks
The report also notes an increase in the number of countries experiencing significant measles outbreaks. There were 37 such countries in 2022, compared with 22 the previous year. The most affected continents were Africa and Asia.
“The rise in measles outbreaks and deaths is impressive but, unfortunately, not surprising, given the decline in vaccination rates in recent years,” said John Vertefeuille, PhD, director of the CDC’s Global Immunization Division.
Vertefeuille emphasized that measles cases anywhere in the world pose a risk to “countries and communities where people are undervaccinated.” In recent years, several regions have fallen short of their immunization targets.
Vaccination Trends
In 2022, there was a slight increase in measles vaccination after a decline exacerbated by the COVID-19 pandemic and its impact on global healthcare systems. However, 33 million children did not receive at least one dose of the vaccine last year: 22 million missed the first dose, and 11 million missed the second.
For communities to be considered protected against outbreaks, immunization coverage with the full vaccine cycle should be at least 95%. The global coverage rate for the first dose was 83%, and for the second, it was 74%.
Nevertheless, immunization recovery has not reached the poorest countries, where the immunization rate stands at 66%. Brazil is among the top 10 countries where more children missed the first dose in 2022. These nations account for over half of the 22 million unadministered vaccines. According to the report, half a million children did not receive the vaccine in Brazil.
Measles in Brazil
Brazil’s results highlight setbacks in vaccination efforts. In 2016, the country was certified to have eliminated measles, but after experiencing outbreaks in 2018, the certification was lost in 2019. In 2018, Brazil confirmed 9325 cases. The situation worsened in 2019 with 20,901 diagnoses. Since then, numbers have been decreasing: 8100 in 2020, 676 in 2021, and 44 in 2022.
Last year, four Brazilian states reported confirmed virus cases: Rio de Janeiro, Pará, São Paulo, and Amapá. Ministry of Health data indicated no confirmed measles cases in Brazil as of June 15, 2023.
Vaccination in Brazil
Vaccination coverage in Brazil, which once reached 95%, has sharply declined in recent years. The rate of patients receiving the full immunization scheme was 59% in 2021.
Globally, although the COVID-19 pandemic affected measles vaccination, measures like social isolation and mask use potentially contributed to reducing measles cases. The incidence of the disease decreased in 2020 and 2021 but is now rising again.
“From 2021 to 2022, reported measles cases increased by 67% worldwide, and the number of countries experiencing large or disruptive outbreaks increased by 68%,” the report stated.
Because of these data, the WHO and the CDC urge increased efforts for vaccination, along with improvements in epidemiological surveillance systems, especially in developing nations. “Children everywhere have the right to be protected by the lifesaving measles vaccine, no matter where they live,” said Kate O’Brien, MD, director of immunization, vaccines, and biologicals at the WHO.
“Measles is called the virus of inequality for a good reason. It is the disease that will find and attack those who are not protected.”
This article was translated from the Medscape Portuguese edition.