Another reason to vaccinate against measles
The measles virus, in and of itself, is serious. But new research shows it can have lasting effects on your child’s health, strengthening the case for vaccination.
Scientists recently confirmed what had long been suspected: Measles infection weakens the immune system, an effect that can last years, according to an article in the Nov. 1, 2019, issue of Science.
“This gives a second argument” for measles vaccination, said Janelle C. Laudone, MD, pediatric hospitalist at Cape Cod Hospital, Hyannis, who was not associated with the study.
Researchers wrote that health experts knew the risk of illness and death increased after measles infection, but not why. During a recent measles outbreak in the Netherlands, researchers drew blood samples from 77 unvaccinated children before and after they became infected and compared the range of antibodies in the blood. Antibodies (proteins that inactivate or help kill viruses and bacteria) were 11-73 percent lower following infection.
A related study that examined blood from the same group of children found that while the total number of lymphocytes (white blood cells that fight infection) in the children’s blood recovered soon after their measles rash had passed, their immune systems remained suppressed for as long as five years.
“I think it (the research) was well done,” Dr. Laudone said. “It’s enough to draw some conclusions.”
A Returning Threat
The authors of the Science article wrote that health records suggest increases in illness and death following measles infection may last as long as five years. Before measles vaccines were introduced in the early 1960s, measles may have contributed to up to half of all childhood deaths from infections, with most deaths from diseases other than measles.
Measles is extremely contagious and can be fatal. Prior to widespread use of vaccines, nearly all children caught measles by age 15, according to the Centers for Disease Control and Prevention. Each year in the decade prior to 1963, 3-4 million people in the United States were infected, 48,000 were hospitalized and 400 to 500 died.
Widespread vaccination dropped infection rates and, in 2000, measles was declared eliminated in the U.S. But outbreaks have returned in recent years, mainly in areas with low vaccination rates. The CDC says 1,276 cases in 31 states, including Massachusetts, have been reported in the U.S. from Jan. 1 to Dec. 5, 2019. Of these, 75 percent were in New York. This is the highest amount in several years – in 2016, only 86 cases were reported.
Measles remains a threat in other countries. More than 140,000 people died from it in 2018, the CDC and the World Health Organization estimate.
Infection and Symptoms
Measles is so contagious that if an infected person coughs or sneezes in a room, someone else walking into the room within two hours could catch the disease, Dr. Laudone said. That is why if someone suspects they may be infected, they should call their doctor and not drive to a clinic or physician’s waiting room. The doctor will arrange to see them away from other patients, she said.
“If you are around an infected person, 90 percent of (unvaccinated) people will get it,” Dr. Laudone said.
Symptoms start one to two weeks after exposure, she said, and include fever, cough, runny nose and red, watery eyes. Three to five days after those symptoms begin, small, red bumps appear and the rash may spread from head to all parts of the body, accompanied by a fever as high as 104 degrees, according to the CDC. Children under 5 and adults over 20 are more likely to develop complications, such as diarrhea and ear infections.
More severe complications include:
- Pneumonia, the biggest killer of children with measles, and
- Encephalitis (brain swelling), which can cause convulsions, deafness and intellectual disability, according to the CDC.
People with compromised immune systems are at more risk of contracting measles, and unvaccinated pregnant women may deliver early or their baby may be low-weight.
Measles vaccine is usually given as part of an MMR vaccine, which also protects against mumps and rubella. The vaccine is given twice: first, at 12-15 months and second, at 4-6 years.
Dr. Laudone noted the effectiveness of the measles vaccine.
“Not all vaccines are as effective,” she said, adding that the first dose conveys 93 percent protection and the second dose, 97 percent. For comparison, the flu vaccine has varied in effectiveness over the past decade from 19-60 percent, the CDC estimates.