SPRINGFIELD, IL - Despite concerns among legislators that vaccine exemptions are too loose in Illinois, the percentage of kindergartners vaccinated in Illinois is above the national average.
The Center for Disease Control reports in its latest findings that 95.5 percent of Illinois' kindergartners are vaccinated for measles, mumps and rubella (MMR), 94.6 percent are immunized for diphtheria, pertussis and tetanus (DPT) and 96.6 have had the varicella (chicken pox) vaccine.
The CDC data shows that Illinois is one of the top states for vaccinations, ranking higher than California and Florida, and just behind Texas and New York -- all of which have larger populations.
A recent outbreak of measles in a Palatine daycare center prompted Springfield legislators to introduce legislation to further restrict citizens' right to choose when and whether to vaccinate their children. Despite the CDC data and the fact that the children infected with the measles were too young to be vaccinated, the bill was introduced and is causing concern among parents as well as civil liberty and First Amendment groups.
Pediatricians appealing to lawmakers for tougher vaccine exemption rules say they are concerned those claiming exemptions could be endangering what's called herd immunity levels - a community environment with a high rate of vaccinations that keeps a virus from spreading. That rate, ideally, is 95 percent of the population.
“In order for a community to have herd immunity, you really need to maintain vaccination rates around 95 percent,” said Dr. Tina Tan, a pediatric infectious disease specialist at Lurie Children’s Hospital in Chicago. “Otherwise, what happens is, that when the rates drop below 95 percent, you can have the reemergence or reappearance of these preventable diseases occurring in individuals that are either not vaccinated or are too young to be vaccinated.”
The 95 percent rate Dr. Tan espouses is an updated number. Until recently, an acceptable herd immunity threshold rate for the MMR vaccine varied between 83 percent and 94 percent. A CDC chart shows the varying recommended levels for the desired herd immunity in 1999:
Over the years, the concept of herd immunity has raised the issue of legal and ethical consequences among the medical community. In the Oxford Journal, three infectious disease specialists admit mandating vaccines on a general population does raise the likelihood of adverse reactions to vaccines, but that the government requiring the vaccines must assume liability.
Insofar as vaccination is encouraged in part to provide indirect protection to unvaccinated individuals, there is the implication of risk—albeit a very small risk—being imposed on certain individuals for the benefit of other individuals. This may have implications—different in different cultural, ethical, or legal contexts—for government liability in circumstances of adverse events to vaccines. Viewed from this perspective we find that indirect protection, the basis of “herd immunity,” raises many interesting and important issues about individual and public values.
The Illinois legislature is dealing with three different bills that could change the state's current religious exemption status: Senator Mulroe's SB 1410, Senator Radogno's SB 1776, and State Rep. Zalewski and McAuliffe's HR 144.