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Table of Contents

Overwhelmingly, American parents get their children immunized. In 1997, immunization levels among children are at their highest ever. The following chart from the National Immunization Program shows the average percentage of children who had received their childhood vaccinations during the 1995-1996 school year.

Percent of U.S. children who have received immunizations, 1995-1996 school year*(1)
Vaccine In Head Start programs In licensed day care facilities K-1st grades
Diphtheria/ tetanus/ pertussis 97 95 98
Polio 97 95 98
Measles 98 95 99
Rubella 98 95 99
Mumps 98 95 99
*Adapted from a chart created by the National Immunization Program. The values in this table are weighted average percents based on preliminary data. The information for K-1st grades was gathered from immunization assessments conducted for school entry.

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Health Professionals

Public Health Officials and Public Health Workers

National and International Organizations

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What about Information on the Internet?

How do you know if vaccine information you find on the Internet or in other sources is accurate? Today's media capabilities and the Internet are wonderful tools for making information widely and rapidly available, but they also make readily available information that is not reviewed for scientific accuracy.

1. The ownership of the site should be clear.
 Is the name of the organization or individual posting the information in clear view? Look for highlighted text that tells you more about the author of the site. In some programs, the ownership can be found by clicking "View" and then "Document Source" or "Document Information."
2. The information provided should be based on sound scientific study.
 Scientists discover truth by testing their findings repeatedly, to be sure that their thinking and methods are not flawed, influenced by their own assumptions, or marred by special circumstances. Studies with hundreds of participants or cases bear more weight than descriptions of a single case. The most useful studies compare the findings in one group of people or cases with the findings in another group (control groups). A mark of sound scientific study is that the findings are endorsed by groups or institutions dedicated to science, such as professional associations or universities.
3. The site should carefully weigh the evidence and acknowledge the limitations of the work.
 Think: What does the weight of the evidence indicate? If conclusion #1 is found in three studies, but conclusion #2 is found in 30 studies, which is more likely to point to truth? Be wary of people who proclaim that they, and only they, have discovered the "hidden truth." The scientific approach takes time, and often, answers are slow in coming or don't come at all. This can be very frustrating if the answers will have an impact on our--or our children's--health and well-being. Solid researchers, however, are not afraid to address the weaknesses as well as the strengths of their findings, to say that the findings were inconclusive, or to say that additional research is needed before any conclusions can be drawn. A scientifically sound web site will reflect these circumstances.
4. Beware of "junk science" and suggestions of "conspiracies."
 The hallmarks of junk science are hasty, and often sensational, claims that other scientists have not seen, reviewed, or verified. Media attention does not necessarily mean a claim is true. "Conspiracy" theories often offer a quick and exciting answer to a puzzle. Think: If I take apart the pieces of "evidence," do they really fit together again?
5. The individuals or group providing the information should be qualified to address the subject matter.
 Beware of information attributed to unnamed "noted researchers" or "world-renowned scientists." A researcher who has done good, solid work would insist that his or her name be attached to that work, even if it's controversial. Who stands behind the information? What educational background do they have that relates to the health topic area? What other work have they published, and where?
6. Arguments should be based on facts, not conjecture.
 Beware of sites that mix fact with fantasy, without distinguishing between the two. As with junk science, the resulting "theories" can be sensational but are not scientifically sound.
7. The motives of the site should be clear.
 Is the site a sales and promotional device? There is nothing wrong with selling books and tapes, or enlisting you in a cause, but motives should be clear.
8. The information provided should make sense.
 Is it too good to be true? ("Rub peanut butter on your knees and you'll never have cancer!") Or too awful to be true? ("Millions die when injected with vaccines!") Then it probably isn't true.
9. One sign of a scientifically sound Internet site is that it contains references from and to recognized peer-reviewed publications.
10. You should be able to obtain additional information if you need it.
 Is an e-mail or postal address, or a telephone number, provided for further information? Is a reading list or source list provided? Is the reading available through a public library, or is the list a source of income for the site owner?
If government documents or publications are referenced, remember that they are usually available free or at low cost through the publishing agency or the Superintendent, Government Printing Office, in Washington, DC, toll-free telephone 1-888-293-6498; fax (202) 512-1262.
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1. National Immunization Program. Information of Interest: Partnerships, Working Together to Sustain Success. Proceedings of the 31st Annual National Immunization Conference. May 19-22, 1997. Atlanta, CDC, National Immunization Program, 1997: 67.

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