Measles: “An Imminent Threat”

 

One of the best measures of a healthy and prosperous nation is how well immunized its citizens are against vaccine-preventable diseases. Childhood vaccination rates in the United States have traditionally been high compared with less developed countries, where families have greater difficulty overcoming economic, religious, and political obstacles in order to get children the protection they need to avoid invisible yet aggressive pathogens.

On The PediaBlog last week, we examined a report issued by the Centers for Disease Control and Prevention and the World Health Organization showing that 25 million children around the world failed to receive life-saving vaccines during the pandemic, reversing the dramatic, decades-long trend of improving global vaccination coverage. While vaccination rates in the Americas fell in 2021 — 10% of children had zero doses in 2021 compared to 3% in 2015 — the biggest increases in “zero doses” of vaccines in children occurred in low- and middle-income countries in Africa (42%), Southeast Asia (25%), and the Middle East (11%).

By Wednesday, CDC and WHO were warning that too many children are now “dangerously susceptible” to getting one of the most contagious infections humans have ever encountered:

Measles vaccination coverage has steadily declined since the beginning of the COVID-19 pandemic. In 2021, a record high of nearly 40 million children missed a measles vaccine dose: 25 million children missed their first dose and an additional 14.7 million children missed their second dose, a joint publication by the World Health Organization (WHO) and the United States Centers for Disease Control and Prevention (CDC) reports. This decline is a significant setback in global progress towards achieving and maintaining measles elimination and leaves millions of children susceptible to infection.

 

The joint statement calls measles “an imminent threat in every region of the world” that requires “urgent global action.”

The situation is grave: measles is one of the most contagious human viruses but is almost entirely preventable through vaccination. Coverage of 95% or greater of 2 doses of measles-containing vaccine is needed to create herd immunity in order to protect communities and achieve and maintain measles elimination. The world is well under that, with only 81% of children receiving their first measles-containing vaccine dose, and only 71% of children receiving their second measles-containing vaccine dose. These are the lowest global coverage rates of the first dose of measles vaccination since 2008, although coverage varies by country

Measles anywhere is a threat everywhere, as the virus can quickly spread to multiple communities and across international borders. No WHO region has achieved and sustained measles elimination. Since 2016, 10 countries that had previously eliminated measles experienced outbreaks and reestablished transmission.

 

Measles is a respiratory virus spread by breathing in airborne droplets or auto-inoculation of the eyes, nose, or mouth after touching a contaminated surface. Early symptoms — fever, runny nose, cough, conjunctivitis — appear about a week after exposure, though person-to-person transmission can occur days before symptoms are felt. An observant clinician can observe Koplik spots — small white-blue dots on the inner surface of the cheeks — 2-3 days before the classic pink, maculopapular rash develops all over the body (see graphic from the JAMA Patient Page below).

 

Although many children develop complications (ear infections, pneumonia, croup, and diarrhea are not uncommon), the vast majority of children infected by the measles virus survive the illness. Respiratory and neurologic complications — acute encephalitis occurs in about 1 in every 1,000 cases — result in most pediatric fatalities. Similar to most infectious diseases, we are not all equally vulnerable to bad outcomes from measles, according to the American Academy of Pediatrics Red Book:

Case-fatality rates are increased in children younger than 5 years, pregnant women, and immunocompromised children, including children with leukemia, human immunodeficiency virus (HIV) infection, and severe malnutrition (including vitamin A deficiency).

 

Like several other viral infections (polio, chickenpox, and COVID-19 immediately come to mind), there may be more misery in store when the acute symptoms and telltale rash resolve:

Measles inclusion body encephalitis (MIBE) is a rare manifestation of measles infection in immunocompromised individuals usually presenting within 1 year of measles infection. Disease onset is subacute with progressive neurologic dysfunction occurring over weeks to months. Subacute sclerosing panencephalitis (SSPE) is a rare degenerative central nervous system disease characterized by behavioral and intellectual deterioration and seizures that occurs 7 to 11 years after wild-type measles virus infection, occurring at a rate of 4 to 11 per 100 000 measles cases. Rates of SSPE as high as approximately 1:1000 measles case have been seen in some recent studies, with the highest rates in children infected before 2 years of age.

Several recent studies have documented that children who have had measles have long-term blunted immune responses to other pathogens and increased mortality attributable to the known effects of measles virus on lymphocytes. This effect is another reason why measles prevention is so important.

 

The best way to prevent measles is for children to get two doses of the MMR vaccine — the first dose at 12-15 months of age and the second between 4-6 years old. Pediatricians like Megan Moreno, M.D. know from decades of research that the MMR vaccine is very effective and extremely safe:

The measles vaccine comes as a combination vaccine called MMR. The MMR vaccine includes protection for measles, mumps, and rubella. Pediatricians recommend that all children receive 2 MMR shots, which provides 97% effective protection against measles. Once your child has had those 2 shots, there is no need for booster doses in the future. Most children who get the MMR vaccine have no negative adverse effects. There have been many scientific studies of the MMR vaccine, and no studies have found a link between MMR vaccine and autism.

 

Every visit to the pediatrician’s office is an opportunity to make sure children and teenagers are staying up-to-date on their routine immunization schedules. Parents can also sign in to their pediatric provider’s online patient portal and review the immunization status and other data contained in their child’s electronic health record. Working together, parents and pediatricians can help preserve children’s health by preventing devastating infectious diseases like measles.

 

(Image: “Measles” — JAMA Pediatrics Patient Page)

 

source http://www.thepediablog.com/2022/11/28/measles-an-imminent-threat/