PHILADELPHIA, April 11 /PRNewswire-USNewswire/ -- News stories about an
allegedly harmful link between the mumps, measles and rubella vaccine and
the onset of autism had little effect on whether U.S. parents immunized
their children, according to a review of immunization records and news
stories. Parents' decisions were more likely influenced by recommendations
from their child's pediatrician, the researchers said.
Researchers from The Children's Hospital of Philadelphia and The
University of Louisville School of Medicine report on the review of data in
the April issue of the journal Pediatrics. The data was collected from
public-use files of the National Immunization Survey from 1995 to 2004. It
compared immunization records of 215,643 children ages 19 months to 35
months with spikes in news stories about the MMR vaccine and autism. The
news accounts were gathered from a database known as LexisNexis, which
tracks newspaper, television and radio news.
The number of children not receiving the mumps, measles and rubella
vaccine (known as MMR) increased after February 1998, when a scientific
study proposing a link between the MMR vaccine and autism appeared in the
British journal The Lancet. After two years, the U.S. numbers of
unvaccinated children then declined and did not rebound when the MMR-autism
link started to receive widespread coverage in the mainstream press,
suggesting a limited influence of news media on MMR immunization rates in
the U.S.
"If providers become more cautious during a period of controversy, then
public health officials should insure providers are given timely advisories
and access to credible recommendations," said Michael J. Smith, M.D, lead
author of the study while formerly at Children's Hospital. Smith is now a
pediatric infectious disease specialist at the University of Louisville
School of Medicine. "Our findings suggest that physicians may have been an
important buffer against the potential negative impact of media coverage of
immunization controversies."
The Lancet study, led by Andrew Wakefield, was flawed and later
discredited, although widely publicized in the United Kingdom. National
rates of MMR immunization in Britain fell from 92 percent to 73 percent
following publication, resulting in measles outbreaks and the first measles
death in the U.K. in more than a decade.
The Children's Hospital study set out to provide the first population
estimates of MMR vaccination rates in the U.S. following publication of the
Wakefield study and its subsequent media coverage. According to the data,
nearly 1 in 50 U.S. children missed the opportunity for MMR immunization in
the two years following the Wakefield publication. In private physician
practices non-immunization rose as high as 1 in 40 children.
Significant mainstream media coverage of the MMR-autism controversy did
not begin in the U.S. until almost two years after the Lancet paper. By
that time, the number of children not receiving their MMR vaccinations was
returning to the pre-Wakefield study level. Children were identified as
intentionally missing MMR vaccinations if they were up to date for other
childhood immunizations including hepatitis B, polio, diphtheria, tetanus,
pertussis and Haemophilus influenzae, but not MMR. The current study looked
at immunization rates through 2004.
The decision to immunize children is influenced by three things: the
parents' willingness, the health care provider's attitude and input toward
guiding the decision, and the vaccine's availability. Since there was no
supply shortage during the study period, the decline can only be attributed
to either the parents' or the health care provider's reluctance to
vaccinate. Some medical providers, made aware of the Wakefield study, may
initially have become hesitant to administer the MMR vaccine, said the
authors.
"The lesson for the public health community may be that the willingness
to immunize a child is a story played out in the examination room during
private conversation between the doctor and family," said Smith. "Updating
the doctor with the most credible information and with strategies for
discussing vaccine safety with parents may be the most efficient way to
guarantee successful immunization practices in the face of increasing
amounts of often unreliable and misleading information."
Co-authors in the study are Susan S. Ellenberg, Ph.D., from the
University of Pennsylvania School of Medicine, Louis M. Bell, M.D. and
David Rubin, M.D., MS.C.E, at The Children's Hospital of Philadelphia. To
read the full article, go to
http://www.pediatrics.org/cgi/content/full/121/4/e836
About The Children's Hospital of Philadelphia: The Children's Hospital
of Philadelphia was founded in 1855 as the nation's first pediatric
hospital. Through its long-standing commitment to providing exceptional
patient care, training new generations of pediatric healthcare
professionals and pioneering major research initiatives, Children's
Hospital has fostered many discoveries that have benefited children
worldwide. Its pediatric research program is among the largest in the
country, ranking third in National Institutes of Health funding. In
addition, its unique family-centered care and public service programs have
brought the 430-bed hospital recognition as a leading advocate for children
and adolescents. For more information, visit http://www.chop.edu.
This news release was issued on behalf of Newswise(TM). For more
information, visit http://www.newswise.com.
SOURCE The Children's Hospital of Philadelphia
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Related links:
http://www.chop.edu
http://www.newswise.com
http://www.pediatrics.org/cgi/content/full/121/4/e836
CONTACT:
Juliann Walsh of Children's Hospital of
Philadelphia, +1-267-426-6054, Walshj1@email.chop.edu; or Anne
Eldridge of University of Louisville, +1-502-852-0943,
Anne.eldridge@louisville.edu
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