Vaccination Coverage: Where We’re At and Where We’re Going
With school back in full swing, it won’t be long before parents start seeing report cards. While report cards may reflect a child’s performance on class tests and quizzes, grades alone can not determine if a child is working hard to reach their full potential. When it comes to immunizations, yearly vaccination coverage data is often used in much the same way. A report is made that estimates the previous year’s vaccination coverage, but the data needs to be put in perspective in order to be put to good use.
When it comes to vaccination coverage among young children in the US, the yearly National Immunization Survey is the ultimate benchmark. Year after year data sets are compiled and used for ongoing analysis of vaccination levels, pointing to successes and shortfalls. These reports help us to determine where we’ve been and where we’re headed.
This year’s 2013 “report card” for children 19-35 months of age was recently published in a Morbidity and Mortality Weekly Report (MMWR) on Friday, August 29, 2014. It is entitled, “National, State, and Selected Local Area Vaccination Coverage Among Children Aged 19-35 Months – United States, 2013” and the survey highlights the following:
Where We’re At
The data collected suggests that vaccination coverage among children aged 19–35 months increased relative to the 2012 estimates for some vaccines (rotavirus, HepA and HepB birth dose) and remained stable for the others. While less than 1% of children had not received any vaccination, it’s important to note that some communities remain at risk of disease outbreak due to pockets of unvaccinated children. Some of the most concerning data presented has to do with the MMR vaccine which helps prevent measles, mumps and rubella. The report states:
“Despite a national MMR vaccination coverage level of 91.9%, one child in 12 in the United States is not receiving their first dose of MMR vaccine on time, underscoring considerable measles susceptibility across the country.”
Of course, vaccination coverage varies by state, but the report indicated as many as 17 states that had vaccination rates below 90% for one dose of the two dose MMR vaccine series. These states included Alabama, Arkansas, Colorado, Kansas, Kentucky, Louisiana, Michigan, Missouri, Montana, New Mexico, Ohio, Oklahoma, Oregon, South Carolina, Virginia, West Virginia, and Wyoming.
It’s important to realize that each disease has a different immunity threshold, which is defined as the estimated vaccination rate that is needed to keep the disease from spreading within a community. The immunity threshold for measles is high at 95%, due in large part to the extremely contagious nature of the disease and the ease of which it can spread through the air. For mumps and rubella the threshold is a bit lower at about 86%. But when we see clusters of people who haven’t been immunized with the MMR vaccine, it’s easy to understand why we are also seeing numerous outbreaks. So far this year we’ve seen the highest number of reported measles cases in the U.S. since the disease was declared eliminated in this country in 2000.
This report card is like a warning sign for parents, providers and public health professionals. Pockets of unvaccinated persons can occur even in states with high vaccination coverage so everyone should be on heightened alert. It is imperative that state health departments be continually accessing measles susceptibility at the local level, that clinicians be on the lookout for any signs of measles cases, and that parents do their best to vaccinate their children on time.
Where We’ve Come From
Despite the ongoing risks of disease, we must acknowledge just how far we’ve come in our fight. Over the course of the past 20 years we’ve seen some amazing benefits of our nation’s vaccination program. For instance, by vaccinating children born between 1994 and 2013, it’s estimated that we’ve prevented 322 million illnesses which is more than the current population of the entire U.S. We’ve also helped avoid 732,000 deaths, which is greater than the population of Boston, MA. And if saving lives and sparing people from illness wasn’t enough, we’ve saved nearly $1.4 trillion in total societal costs (which includes $295 billion in direct costs), which represents $4,473 for each American.
Where We’re Going
Each year we get a “report card” and each year it is used to help devise strategies and tools to increase immunization rates. Since the survey sample size includes approximately 30,000 children, we’re able to subdivide the data to examine rates among different groups, such as by income level, race, education level of mothers, and various other factors. For instance, the 2013 data indicated that children living below the poverty line had lower coverage for several vaccines, despite the existence of programs like Vaccines For Children (VFC) which provides vaccines for uninsured children. Vaccination coverage estimates are further broken down by region, state, and select cities. This can identify high risk geographical locations which then helps to determine where efforts are needed to try to increase coverage (such as in areas where the MMR and DTaP vaccination coverage rates drop below the immunity thresholds).
The simple fact is that the more we know about where we’re at, the more we can help influence where we’re going.
For the complete data contained in the 2013 National Immunization Survey for Children, and for a comparison of how the 2013 compares to years past, visit the CDC website: http://www.cdc.gov/vaccines/imz-managers/coverage/nis/child/index.html#chart.