Joe Kurland, MPH
Something strange has been happening over the past few years. Infectious diseases are fighting back against the tools that have previously succeeded in protecting us all. In 2000, the U.S. announced that measles had been eliminated from the country. Our tools were so effective and some vaccine-preventable diseases were so rare, that they were all but unknown to a generation of parents and doctors. Sadly, these tools became a victim of their own success.
Measles is caused by a virus. Sometimes people say “it’s just a virus,” which ignores the fact that some of the most dangerous germs we know are viruses, measles included. It gets into your body when you inhale droplets sneezed or coughed out by someone who’s infected and is considered to be one of the most contagious diseases of which we known, with research showing that, on average, one sick person will infect as many as 18 people who are not protected. Nine out of 10 unimmunized people exposed will get measles because it is that easy to catch. This is partly because measles is an airborne virus; it can survive and infect other people who simply walk through the same room as an infected person. And the infected person doesn’t have to be in the room. The droplets are so small that the air in a room stays infectious for up to two hours after the ill person has left.
OK, measles spreads easily. But is it really that scary? What does it do?
After you’re exposed to measles, it takes between seven and 14 days to develop signs of the infection. The signs include high fever, cough, runny nose and red, watery eyes. You get a rash three to five days after those symptoms start. At first it looks like flat, red spots that show up on your head by your hairline and then spreads like a bucket of rash downwards. It covers your face, neck, chest, belly and finally your arms, legs and feet. The rash may be small, individual, raised, red bumps with flat tops, or they can join into large patches. Four days before the rash shows up, you can spread the virus to others.
For many people, the rash and fever go away after a few days, but for some there are complications. These can vary in severity from mild effects like ear infections and diarrhea to more severe symptoms such as pneumonia and swelling of the brain (encephalitis). Pneumonia is the most common (1 in 20 cases) cause of measles-related death in children, and encephalitis, while less common (1 in 1,000 cases), can cause seizures which may lead to deafness or mental disabilities. For every 1,000 children who get measles, one or two will die from it. Infections in pregnant women may result in premature delivery or a low-birth-weight baby.
You have my attention. What can I do if I’ve never had my shots and may have been exposed?
In the U.S., there are several factors working in a person’s favor:
A modern health system: Clinicians watch for measles and other diseases. If a case is found, they are required, by law, to report it to their local public health departments. The public health experts (epidemiologists) interview the sick person, notify anyone who may have been exposed and work to stop measles in its tracks by having people stay home while potentially contagious.
Effective medication: There are no antiviral medicines available to treat measles. People exposed to the sick person can protect themselves if they act quickly. If the measles vaccine (MMR shot) is given in the first few days after exposure, it can stop the virus from making you ill.
Community immunity: This is perhaps the most effective tool we have. Community immunity (also known as herd immunity) stops a disease outbreak like a firewall by stopping the virus from reaching new hosts. If you surround an infected person with people who can’t get infected with measles — because they are immune, immunized or were previously infected — the virus cannot spread and the outbreak will end. Community immunity is especially important for families where someone is immune-suppressed or who have children younger than 1 year old who are too young to be immunized.
So, the vaccine is the best protection against measles. But some say the MMR vaccine is safe, while others say it is risky and may harm my child. What’s true?
All medical treatments have some risk. But after many studies examined MMR (measles, mumps and rubella) and other vaccines, the final word is the MMR vaccine is safe and rarely causes a severe allergic reaction.
And there is no link between the MMR vaccine and autism spectrum disorders. The association between the two repeatedly has been investigated, and no study has shown results linking the vaccine to the symptoms. In fact, newer research into autism suggests that it’s the result of unusual networking in the fetal brain in the weeks following conception.
What were you saying about our tools being a victim of their own success?
Because the vaccines and immunizations our medical system uses are so effective, the scary, deadly diseases they prevent are now rare. Paralytic polio, babies born with congenital rubella syndrome, tetanus, diphtheria are unknown and forgotten to an entire generation of parents. Because the effects of these diseases were forgotten, the tiny risks for side effects from the vaccines became the focus of concern. Combined with questionable sources in media and on the Internet, fear of vaccines grew. Pockets of underimmunized communities sprung up in cities across the U.S. and provided a foothold for vaccine-preventable diseases, imported from countries with lesser health systems, to resume their toll on a new generation of susceptible children.
But I heard the anti-vaccine community is pretty small and most people follow their pediatricians’ recommendations.
It’s true. Nationally, the number of parents electing to refuse vaccinations is low; however, in some communities, vaccine coverage is less than in war-ravaged Sudan. And this gives the diseases a chance to attack. Measles is so contagious that outbreaks may occur if any more than 5 percent of the community is unvaccinated. Some schools in Oregon and California have reported vaccine rates of 50 percent to 69 percent when anything less than 95 percent vaccinated has great potential for an outbreak.
Vaccines have been so effective that we lost our fear of the diseases they prevented. Amnesia created doubt and hostility towards the utility and need for protection. It is up to parents to protect not only our own children against measles, but in doing so, know that we protect others, too.
For more information:
- Minnesota Department of Health
- Centers for Disease Control and Prevention
- World Health Organization
- California Department of Public Health
Joe Kurland, MPH, is a vaccine specialist and infection preventionist at Children’s Hospitals and Clinics of Minnesota.