HQ Team
December 12, 2022: Nearly 40 million children missed at least one measles dose in 2021, according to a report published by the World Health Organization (WHO), the United States Centers for Disease Control and Prevention (CDC) and several university researchers.
The pandemic has played havoc with the vaccination schedules of children across the world. This decline in vaccinations, especially for measles, is alarming epidemiologists. 25 million children missed their first dose, and an additional 14.7 million children missed their second dose of the vaccination in this period.
Lockdowns during the coronavirus pandemic made it difficult to access medical facilities. Even after the lockdown ended, the healthcare systems found it difficult to follow up with parents. Adding to the problem were the anti-vaxxers, especially in the western countries, whose decision to not vaccinate their children has harmed other children by spreading the disease.
Professor Matthew Ferrari of Penn State University, and one of the authors of the report, is most concerned about measles.
“Measles is one of the most contagious human viruses and can be quite serious if there aren’t sufficient resources to manage symptoms,” Ferrari said in a statement. “In under-resourced settings, as many as 5 percent of children infected with measles could die, and the likelihood of severe outcomes is higher in younger kids.”
Missed doses due to Covid-19 and other emergencies
Ferrari explained that measles vaccination occurs globally through two mechanisms — parents bringing their kids in for routine visits at health facilities and large-scale community-based campaigns that try to reach those with poor access to health facilities.
“Both of these mechanisms were disrupted because of COVID-19,” he said. “Many children missed their scheduled opportunities for vaccination over the last three years, and now is a critical time to allocate resources to making up that vaccination gap before those communities experience large outbreaks.”
The deadly measles outbreak in the Democratic Republic of the Congo in 2018 took more than 6,000 lives in a country already facing its largest Ebola outbreak, highlighting the importance of maintaining essential health services, such as immunization in times of emergency.
Further disease outbreaks will also overwhelm health systems already battling the impact of COVID-19, according to the WHO.
Measles and death rates
Herd immunity prevents outbreaks from taking hold when vaccination rates drop modestly. A disease’s infectiousness is measured by its reproductive number (R0), a concept now familiar to most after the COvid-19 outbreak. The R0 measures how many people a contagious individual will infect.
For measles, the R0 is around 15. When measles gets loose in a population that has not been vaccinated and hasn’t had an outbreak before, it spreads like wildfire.
To determine the actual number of deaths from measles, Ferrari and team fed data into a statistical model created and estimated 9 million people were infected in 2021, causing 128,000 deaths. He expects the number to rise this year and until the vaccination gap caused by the pandemic is closed.
“Most children – more than 80 percent – will be protected by the first dose, but those that are not have very little protection at all,” Ferrari said. “The second dose is critical for catching up those kids that weren’t protected by the first dose.”
Measles upset the immune system and makes people susceptible to diseases they have suffered from earlier. In some cases, this can be as powerful a risk factor as taking immunosuppressive drugs. This “immunological amnesia” was only discovered in 2019, so its scale is not well studied.
In a release, WHO Director-General Tedros Adhanom Ghebreyesus said, “The paradox of the pandemic is that while vaccines against COVID-19 were developed in record time and deployed in the largest vaccination campaign in history, routine immunization programs were badly disrupted, and millions of kids missed out on life-saving vaccinations against deadly diseases like measles. Getting immunization programs back on track is absolutely critical. Behind every statistic in this report is a child at risk of a preventable disease.”
The WHO report is available online.
