More than 100 million children could be at risk for measles because countries around the world are suspending national immunization programs in order to reduce the risk of coronavirus infection, international public health leaders warned on Monday.
So far, 24 low- and middle-income countries, including Mexico, Nigeria and Cambodia, have paused or postponed such programs, according to the Measles and Rubella Initiative, a consortium whose members include UNICEF, the American Red Cross, the World Health Organization, the United Nations Foundation and the Centers for Disease Control and Prevention.
Unlike wealthier countries, where parents typically make appointments to follow a routine vaccine schedule at clinics or private pediatric offices, these countries inoculate large numbers of infants and children in communal settings, like marketplaces, schools, churches and mosques.
Dr. Robin Nandy, the chief of immunization for UNICEF, acknowledged that finding the balance between guarding against the spread of Covid-19, the illness caused by the coronavirus, and preventable diseases like measles was delicate and difficult.
“In our quest to vaccinate kids, we shouldn’t contribute to the spread of Covid-19,” he said. “But we don’t want a country that is recovering from an outbreak of it to then be dealing with a measles or diphtheria outbreak.”
Dr. Nandy said that public health organizations had endorsed new immunization guidelines from the W.H.O., which recognize that while campaigns advocating mass inoculations should be sustained as long as safely possible, temporary suspensions might occur because of reasonable concerns about transmission of Covid-19 to patients and health care workers.
“We have to acknowledge the disruption, whether we like it or not,” Dr. Nandy said. But he urged countries to plan for shipments of vaccines and syringes to be available as soon as an easing of Covid-19 restrictions permitted and, given the limited number of international flights, even to be prepared to charter planes.
Countries should be compiling immunization registries, tracking earlier campaigns and doing risk assessments, to prioritize regions where outbreaks would be most likely and children most vulnerable, he added.
But Dr. Beate Kampmann, director of the Vaccine Centre at the London School of Hygiene and Tropical Medicine, said many countries that already have weak and fragmented health care systems would not be able to collect reliable immunization data.
“There are virtually no registers for vaccinations in West Africa other than parent-held records,” she said, adding that an entire “birth cohort of infants could miss out on vaccinations altogether with serious consequences.”
Before the coronavirus pandemic, measles was already making a resurgence in some places. In 2017, there were 7,585,900 estimated measles cases and 124,000 estimated deaths, according to the World Health Organization. By 2018, the last year for which international figures have been compiled, there were 9,769,400 estimated measles cases and 142,300 related deaths.
In 2019, the United States reported 1,282 measles cases, its highest in more than 25 years. The measles vaccine has been available for more than 50 years.
Countries including Brazil, Bangladesh, the Democratic Republic of Congo, South Sudan, Nigeria, Ukraine and Kazakhstan are currently fighting outbreaks of measles. Among the countries that have postponed their vaccination programs are Bolivia, Chad, Chile, Colombia, Djibouti, the Dominican Republic, Ethiopia, Honduras, Lebanon, Nepal, Paraguay, Somalia, South Sudan and Uzbekistan.
Dr. Kampmann was also concerned about potential outbreaks in wealthier countries in North America and Europe, which do not have national inoculation programs. Because of Covid-19 fears, American pediatric practices are beginning to report significant drops in well-child visits, including those for routine vaccines.
“Even in resource-rich settings there is a danger of measles raising its ugly head in the not-too-distant future,” Dr. Kampmann added, “hence it is even more important to sustain routine immunizations.”
Dr. Melinda Wharton, director of the C.D.C.’s Immunization Services division, said that one upside of current social distancing measures was that if outbreaks of measles occur, transmission might be limited. She said that in recent years, many cases entered the United States from common travel destinations and that the sharp decreases in air travel because of the pandemic might also keep a lid on measles cases.
As of last week, there were 12 confirmed cases of measles in seven jurisdictions in the United States. The C.D.C. is monitoring vaccination rates, Dr. Wharton said.
“We will work with state and local health departments to ensure children who were not able to get vaccinated because of the Covid-19 response get the necessary catch-up vaccinations,” she said.