Measles – small reduction in vaccination would have a large impact

A minor reduction in the uptake of childhood measles vaccination in the US would lead to a disproportionately large increase in case numbers and public health costs, according to new research.

Currently the US has good coverage with regards to the MMR vaccine – only reporting between a few dozen and a few hundred cases each year. All 50 states require children to have the MMR vaccine prior to starting nursery or day-care, although there can be exemptions for medical reasons. However, 47 of these states also allow parents to decline the vaccination for religious reasons, and in 18 states children can be exempted due to ‘personal beliefs’.

Professor of pediatric infectious diseases, Yvonne Maldonado, from Stanford University (CA, USA), commented: “We have a tenuous handle on measles disease now. It’s all dependent on very small increments of vaccination. We really need to focus on making sure that all children are vaccinated to eliminate this disease from the face of the Earth.”

In this study, published recently in JAMA Pediatrics, the team analyzed MMR vaccination data from the Centers for Disease Control and Prevention (GA, USA). They used this to construct mathematical models and predict the effects of declining pediatric vaccination rates, simulating approximately 10, 000 scenarios.

Author, Nathan Lo (Stanford University) explained: “We focused on measles as a case example of the effects of declining vaccine coverage because it is highly infectious. It’s likely to be the first infectious disease causing outbreaks if vaccination declines.”

The researchers reported that a minimal 5% decrease in the number of MMR-vaccinated children aged 2–11 vaccinated would lead to triple the current number of measles cases in this age group. In addition, they estimated that these additional cases could increase annual public health expenditures by at least $2.1 million – approximately $20.000 per measles case.

Senior author Peter Hotez (Baylor College of Medicine, TX, USA) explained the impact of these findings: “I think our study is a wake-up call for what we can expect in the coming months and years as vaccine coverage rates continue to decline in the 18 states that now allow non-medical or philosophical belief exemptions.”

Lo hopes that public health officials and lawmakers will take the study’s findings into consideration, he concluded: “Every year, an increasing number of states are debating non-medical exemptions, which are a critical driver of vaccination coverage. This study quantifies the consequences of a rise in measles cases and state dollars that will be spent if personal belief exemptions that can reduce vaccine coverage are in place.”



Leave A Comment