E-NEWS FROM THE NATIONAL VACCINE INFORMATION CENTER

* * * * * * * * * * * * * * * * * * * * * * *

UNITED WAY/COMBINED FEDERAL CAMPAIGN

#9119

* * * * * * * * * * * * * * * * * * * * * * *

"Protecting the health and informed consent rights of children since 1982."

==========================================================================================

NVIC Note:

LEARN ABOUT POLIO VACCINE RISKS AT NVIC CONFERENCE: The risks associated with polio vaccination, including evidence demonstrating an association between SV40 contamination of polio vaccines and human cancers, will be presented at the Third International Public Conference on Vaccination. Speakers will include:

o John Lednicky, Ph.D., assistant professor and director of virology for molecular pathology and associate director of clinical microbiology, Loyola University, Chicago. Dr. Lednicky has published extensively on the evidence for SV40 infections in children and the relationship between human SV40 infections and cancer.

o Stanley Kops, J.D., a Philadelphia attorney specializing in product liability and personal injury law. An expert on live oral polio vaccine (OPV), including SV40 contamination, he was counsel in two famous federal court decisions in the 1970's and 1980's which held the U.S. government liable for OPV-induced paralysis in children and adults.

o An African human rights activist who has suffered persecution for taking a stand against forced vaccination campaigns using live oral polio vaccine.

SV40 Contamination of Polio Vaccine and Cancer

Institute of Medicine

Telephone News Conference

Oct. 22, 2002

Opening Statement by Marie C. McCormick

Professor and Chair, Department of Maternal and Child Health Harvard School of Public Health and Chair, Committee on Immunization Safety Review

Good morning. On behalf of the Institute of Medicine and the entire committee, Steven Goodman and I would like to welcome reporters to the release of our report, SV40 Contamination of Polio Vaccine and Cancer.

The genesis of this report was a request from the Centers for Disease Control and Prevention and the National Institutes of Health, both of which recognized the need for an independent group of scientists to address growing concerns about vaccine safety in a timely and objective manner. In response to this request, the Committee on Immunization Safety Review was established in January of 2001. The committee comprises 14 members with expertise in a variety of relevant public health and medical disciplines.

The charge to this committee is to examine a series of eight vaccine-safety hypotheses over the course of a three-year study period. Today's report is the fifth in that series. The issues that the committee addresses -- possible associations between vaccines and adverse health effects -- were selected by a working group of federal government vaccine researchers and policy-makers. The committee's task is to look at the science behind a given hypothesis, assess its significance in a broader societal context, and suggest appropriate actions to be taken by federal agencies, researchers, and policy-makers.

The subject of the report being released today is whether exposure to simian virus-40, or SV40, through contaminated polio vaccine has caused cancer in humans.

First, a bit of context: Immunization is widely regarded as one of the world's most effective tools for preventing millions of deaths and cases of disease. In the United States alone, child-vaccination programs have eliminated smallpox and polio and made exceedingly uncommon such debilitating and potentially life-threatening infectious diseases as diphtheria, pertussis, and measles. Along with these benefits have come some concerns about safety; as a result, immunization policies are a subject of public debate in some quarters.

Polio vaccine, first licensed in the United States in 1955, offers a means of preventing poliomyelitis, a highly infectious disease that can result in paralysis of the limbs or respiratory muscles. The vaccine was originally produced using tissue cultures from the kidneys of rhesus and cynomolgus monkeys. In 1960, researchers reported that these tissues could be infected with SV40, a previously unknown virus that can cause a harmless infection in rhesus monkeys. Once the virus was identified, it was determined that some of the polio vaccine administered in the United States between 1955 and 1963 was contaminated with SV40. Steps were taken to alter production and screening techniques, and since 1963, the polio vaccine has been free of SV40.

The contamination of the polio vaccine generated concern because SV40 has been shown to induce tumors in hamsters and to "transform" or change human cells in laboratory cultures by altering the regulation of cell growth and survival. More recently, concern has grown with the detection of SV40 DNA -- as well as the DNA of other viruses -- in some human tumors, most notably mesotheliomas, osteosarcomas, ependymomas, and non-Hodgkin's lymphomas. Evidence from animal studies is consistent with a link between SV40 and these forms of cancer, but epidemiological studies have been inconclusive.

Polio vaccine administered between 1955 and 1963 is assumed to be the primary source of human exposure to SV40 in the United States, but details of the level and extent of the contamination are unavailable. One widely cited estimate is that between 10 percent and 30 percent of the polio vaccine was contaminated with SV40, potentially exposing between 10 million and 30 million Americans to the virus. But that estimate is not enough to determine the number of people who might face an increased risk of illness. Because coming into contact with a virus does not necessarily mean it will take hold and grow, it is impossible to determine how many people actually became infected. Furthermore, infection does not necessarily mean a person will suffer an adverse health consequence.

With concerns that exposure to SV40-contaminated polio vaccine might lead to cancer and the emergence of new literature on the cancer-causing potential of SV40, the committee was asked to review the epidemiological and biological evidence regarding a causal relationship. The committee also held an open scientific workshop in July in Washington, D.C. to discuss the issue.

The committee concluded that the epidemiological evidence was inadequate to accept or reject a causal relationship between exposure to SV40-contaminated polio vaccine and certain cancers. The majority of population-based studies, which carry the most weight in establishing causal relationships, have found no increase in the rates of cancer in people who were immunized during the period of contamination. But the committee found substantial statistical and design limitations in all the studies it reviewed. In many cases, year of birth was used instead of individual vaccination records as a basis for assumptions about who received contaminated vaccine. At this point, researchers have no way to know with certainty which individuals received the contaminated polio vaccine decades ago. Furthermore, the rarity of most of the tumors thought to be associated with exposure to SV40 makes it difficult to do statistically conclusive studies.

The biological evidence was reviewed in terms of three key questions: Does SV40 transform or change cells' production of proteins that regulate cell growth and survival? Can SV40 cause cancer in humans under natural exposure?

Finally, is contamination of the polio vaccine with SV40 responsible for SV40 infection in humans? Specifically, the committee found strong evidence that SV40 contaminated some polio vaccine used from 1955 to 1963, and that SV40 has been shown in laboratory experiments to change or affect cells in ways that are consistent with cancer. However, the evidence is only moderate that SV40 causes cancer under natural conditions outside the laboratory. Accumulated evidence, particularly for mesotheliomas, suggests that it is likely that SV40 is present in some human tumors. Together, these findings suggest but do not prove that SV40 could contribute to some cancers in people.

Some important questions remain, however. What proportion, if any, of the people exposed to SV40-contaminated vaccine were infected? What proportion, if any, of the human cancers in which SV40 is detected are caused by SV40? Is the contaminated polio vaccine the sole source of exposure to SV40? And, did SV40-contaminated polio vaccine cause cancer in vaccine recipients or not?

The concerns about exposure to SV40 through inadvertent contamination of polio vaccine are significant because of the seriousness of cancer as a possible adverse health outcome, and because of the continuing need to ensure public trust in the nation's immunization program. The committee does not recommend a review of polio vaccination policy on the basis of concerns over cancer risks from SV40 contamination, since today's polio vaccine is no longer contaminated. However, it does recommend that the U.S. Department of Health and Human Services coordinate and supplement existing policies and procedures to assure vaccine safety, as part of a move toward developing a comprehensive plan to address vaccine contamination should it ever occur again.

Future research efforts should focus on developing sensitive blood tests and standardized techniques for more definitive detection of SV40 in people who may have been infected. Once the best detection methods and protocols are determined, they should be used to assess the incidence of SV40 infection in humans before the introduction of polio vaccine in 1955 and after the elimination of the contaminated vaccine in 1963. These analyses would help reveal the extent to which the existing SV40 infection in the population can be attributed to sources other than the contaminated polio vaccine. The committee advised against conducting more epidemiological studies of people potentially exposed to the contaminated vaccine until the technical issues of detection and study design have been resolved.

The United States has the responsibility to thoroughly address health concerns stemming from the SV40 contamination of polio vaccine to ensure that any adverse health effects are identified, or to help produce the scientific evidence necessary for assurance that exposure to the contaminated vaccine has not had adverse effects.

Dr. Goodman and I will now take your questions. Since this briefing is being recorded, please state your name and affiliation before asking your question. Thank you.

=============================================

News@909shot.com is a free service of the National Vaccine Information Center and is supported through membership donations. Learn more about vaccines, diseases and how to protect your informed

To unsubscribe from this list, send an email to news-request@909shot.com and type

UNSUBSCRIBE in the body of the email.

NVIC is funded through individual membership donations and does not receive government funding. Barbara Loe Fisher, President and Co-founder.

NOTE: This is not an interactive e-mail list. Please do not respond to messages.