In the year 2000, measles was nearly eradicated in the United States according to the Centers for Disease Control (CDC). Since then, measles outbreaks have been popping up all over the country despite a vaccine being available.  

For this week's Baby Your Baby Podcast, Holly Menino talks with Rich Lakin, the Utah Department of Health's Immunization Program Manager, about why vaccines are so important to achieve community immunity against vaccine preventable diseases. 

What can happen if a large number of people in a community aren’t vaccinated or choose not to vaccinate against preventable diseases like measles?

Community or herd immunity is a form of protection from a disease that occurs when a large percentage of the population has become immune to it, most often through vaccination. If a high enough number of people are vaccinated against vaccine preventable diseases, such as measles, this helps protect individuals who may not be able to receive a vaccine because of immunocompromised conditions. This means people who have a compromised immune system – for example, someone who has had an organ transplant or is receiving radiation or chemotherapy for cancer - can still be protected and have less chances of suffering from these diseases.

Some vaccine preventable diseases – such as measles - are so contagious that if one person has it, 90% of the people close to that person who are not immune to it will also become infected. This is what can happen during a measles outbreak. Infected people can spread measles to others from four days before, through four days after the rash appears.

People who have been vaccinated can still get measles, but there is only a small chance of this happening. Only about 3% of people who receive two doses of the measles vaccine will get measles if they come in contact with someone who has the virus. If a person is fully vaccinated, and does come down with measles, they are more likely to have a mild case of the illness.

So why do people who are vaccinated and come in contact with an infected person still run the risk of getting measles?

There is still a possibility because everyone’s uptake of a vaccine is different. One individual may only have a response rate of 70% when receiving the vaccine, and another person could have a response rate of 90%. If the person with a response rate of 70% is exposed, you could say that their chance is 30% higher of getting the disease than the person whose vaccine response rate is 90%. This does not mean the vaccine didn’t work.

Another consideration affecting the how much protection a vaccine will provide is storage and handling of the vaccine. If the vaccine is compromised because it wasn’t stored at the proper temperature or there were temperature changes during transportation, it could make it less effective.

The infectious nature of vaccine preventable diseases like measles makes it easy to spread in our communities if we are not properly vaccinated. That’s why we recommend everyone healthy enough to receive the vaccine get the full two doses of the MMR vaccine. Not only will this protect you from getting sick, but it will help protect your family and friends, neighbors, classmates, and coworkers.

The Baby Your Baby program provides many resources for all pregnant women and new moms in Utah. There is also expert advice from the Utah Department of Health and Intermountain Healthcare that air each week on KUTV 2News.