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The Vaccine Challenge

Immunization rates have never been higher in the United States. But the national structure that supports vaccination programs is weakening in spots, and the immunization system may be unprepared to handle future large-scale disease outbreaks or the addition of new vaccines, says a report from the Institute of Medicine. It recommends an overhaul of the way the system is financed, as well as increases in public investments to support it.

Every day, 11,000 children are born in this country, each of them requiring a series of recommended vaccinations. If the system cannot keep up and immunization rates fall, the risk of vaccine-preventable disease outbreaks will increase, the report says. A vivid reminder of this is the measles epidemic that began in 1989, spreading to 43,000 children and killing 100 of them. Even now, 300 children die every year from vaccine-preventable diseases. Adults with chronic illnesses such as heart and lung disease also are vulnerable.

Yet state and local public health agencies are not adequately prepared to deliver new vaccines, step up efforts to immunize adults with chronic health problems, or eliminate persistent disparities in vaccine coverage between low-income groups and the general population. Gaps in data collection have created blind spots, leaving the system unable to assess and improve coverage rates. Nor can public health officials adequately monitor the performance of private health care facilities, where most vaccinations take place. In part, these weaknesses reflect deep cuts in federal support of the public health apparatus that undergirds the system.

To remedy this, the report recommends that federal and state governments spend an additional $875 million over five years to strengthen the management of the immunization system. Two-thirds of this money would come from the federal government in the form of grants, with the remainder coming from the states. The report also urges Congress to develop a formula that ensures that states with the greatest need receive extra funding.

As new vaccines become available for widespread use, federal and state governments will likely need additional money to provide vaccines to the poor and uninsured. Congress should anticipate such needs in the near future, the report says. It also recommends that the federal government spend an additional $50 million per year to purchase vaccines for poor and uninsured adults. Collectively, the states ought to share in these costs by spending an extra $11 million to buy vaccines for adults.

Without a coordinated, community-wide tracking system, some individuals — especially children — will fall through the cracks, undetected by public health officials. Variations in reporting systems make tracking difficult, and the report recommends that these systems be standardized.

The importance of monitoring is reflected in surveys indicating that 9 percent fewer poor children complete the full series of the most critical vaccines than other children. If distinct pockets of low vaccination coverage, particularly in poor communities, remain undetected, they will provide a reservoir for future disease outbreaks. — Neil Tickner & Vanee Vines

Calling the Shots: Immunization Finance Policies and Practices. Committee on Immunization Finance Policies and Practices, Division of Health Care Services and Division of Health Promotion and Disease Prevention, Institute of Medicine (2000, approx. 350 pp.; ISBN 0-309-07029-5; available from National Academy Press, tel. 1-800-624-6242; $49.95 plus $4.50 shipping for single copies). Also, the October 2000 issue of the American Journal of Preventive Medicine includes background papers commissioned as part of the IOM study.

The committee was chaired by Bernard Guyer, chair, department of population and family health sciences, Johns Hopkins University School of Hygiene and Public Health, Baltimore. The study was funded by the U.S. Centers for Disease Control and Prevention.

©Allen Russell/Index Stock Photography
Smarter HIV Prevention

For all the advances that have been made in treating HIV, there is no substitute for prevention. Yet new trends in the HIV/AIDS epidemic suggest the need to rethink the way prevention efforts are conducted in the United States.

Recent reports indicate that a false sense of security and growing complacency brought on by treatment advances may be contributing to a resurgence of risky behaviors in some areas. Additionally, a shift in which populations are living with AIDS suggests that prevention efforts may not be effectively reaching those at risk.

To prevent as many new infections as possible, the government needs a better tracking system and a more systematic approach to evaluating programs and allocating funds, says a new report from the Institute of Medicine (IOM).

Tracking is key. In the past 15 years, the number of new AIDS cases among minorities, women, and adolescents has increased considerably. For example, African Americans and Hispanics now account for nearly 66 percent of all new AIDS cases, a twofold increase in that period. During the same time frame, the number of new AIDS cases among men who have sex with men declined by nearly half, from 65 percent to 34 percent — although recent reports suggest that in some areas, infection rates are increasing among this group.

But all of these statistics are based on documented AIDS cases. And because it can take 10 years without treatment and more than 10 with treatment for HIV infection to develop into AIDS, these figures are only able to show where the epidemic has been and not necessarily where it is going. Therefore, the CDC should create a national surveillance system that can accurately track new HIV infections, the IOM report says.

With a clear picture of where the epidemic is spreading, officials at all levels will have a greatly enhanced ability to better direct their HIV prevention resources. In fiscal year 1999, the federal government spent $775 million on HIV/AIDS prevention, or 8 percent of its total HIV/AIDS budget. Thousands of new infections could be avoided each year if greater emphasis were given to prevention and the government was smarter in the way it spent its prevention dollars, the report says. Evaluation data that reflects the cost, effectiveness, and reach of each prevention program would help the government do a better job of investing resources in interventions that work.

courtesy Denise Watkins, Whitman-Walker Clinic

The strategy outlined in the report calls for additional improvements, such as routinely offering prevention services during visits to clinics and doctors’ offices that serve high-risk populations. Federal agencies also need to do a better job in working with state and local organizations to apply the latest research on effective prevention at the community level. And to spur the development of new technologies such as microbicides and vaccines that thwart viral transmission, federal agencies should increase research funding and provide incentives to the private sector to invest in research.

But the effectiveness of these steps will be severely curtailed if federal, state, and local officials do not exert greater leadership to remove social and political obstacles, the report warns. Policies that require public funds to be used solely for abstinence-only sex education should be abolished and barriers limiting access to sterile injection equipment for drug abusers should be lifted. At the same time, federal agencies should work to make sure that resources for substance-abuse treatment are sufficient to provide services to those requesting it. — N.T. & V.V.

No Time to Lose: Getting More from HIV Prevention.Committee on HIV Prevention Strategies in the United States, Division of Health Promotion and Disease Prevention, Institute of Medicine (2000, approx. 180 pp.; ISBN 0-309-07137-2; available from National Academy Press, tel. 1-800-624-6242; $39.95 plus $4.50 shipping for single copies).

The committee was co-chaired by Harvey Fineberg, provost, Harvard University, Cambridge, Mass., and James Trussell, associate dean, Woodrow Wilson School of Public and International Affairs, Princeton University, Princeton, N.J. The study was funded by the U.S. Centers for Disease Control and Prevention.

Safely to School

A number of financially strapped school districts around the country — especially in small cities and rural areas — are looking for ways to save money on transportation. They could do that by shifting older students from school buses to public transit. The idea isn’t new. For decades, districts in many urban areas have relied on transit to get kids to and from school.


Today the idea appeals to some transit administrators hungry for more riders and to budget-conscious county officials. Perhaps by coordinating transportation services for students with local public transit agencies, overall costs could be lowered, they reason. But there are legal roadblocks, and the National Transportation Safety Board has entered the debate, asking whether stricter safety regulations make school buses the safer way to go. To answer the question, Congress asked the National Research Council to investigate the relative safety of different modes of transporting students to school.

Operators of “yellow bus” fleets contend that their vehicles are indeed safer because of more stringent federal and state regulations. Their buses have stricter design requirements, passengers are not permitted to stand while a bus is moving, traffic is required to stop when students board or disembark, and school-bus drivers must get extra safety training, they argue.

On the other hand, transit has an enviable safety record compared with other modes of surface transportation. Still, no one can say for sure which is safer for students. National statistics do not provide a direct safety comparison of the various ways that children get to school, and little published research is available. To clarify the situation, the Research Council committee conducting the study will examine national databases and accident records to see how much can be learned about the relative safety of school buses, transit buses and rail, vans, private vehicles, bicycles, and students on foot. The committee’s report is expected in 2002. — N.T. & V.V. (See listing under New Projects.)

Learning from Littleton

Although incidents of violent crime still are the exception in the nation’s schools, high-profile campus shootings in communities such as Littleton, Colorado, and Pearl, Mississippi, have fed the perception that public schools are inherently dangerous. To be sure, the cost of school violence has been high in areas where students and adults have experienced physical and emotional suffering — or even death. But the overall impact of violence exceeds that of personal injury. A sense of fear in the classroom can affect everything from the quality of the learning environment to teacher-recruitment efforts.

At the request of Congress, a new study by a committee of the Research Council and Institute of Medicine will prepare case studies of several school shootings that harmed multiple victims. A final report is expected in 2001. — V.V. (See listing under New Projects.)

Measuring Mercury

In the United States, about 40 tons of mercury are released annually into the atmosphere as a byproduct of fossil-fuel burning power plants, especially those that burn coal. It makes its way into oceans, lakes, and streams and is converted into methylmercury by aquatic microbes. This organic form of the chemical accumulates in the food chain as the microbes are eaten by larger organisms that in turn are eaten by other fish. As a result, predators such as tuna and shark often contain high levels of methylmercury.

And since fish is a common component of the human diet, the Environmental Protection Agency has developed guidelines for protecting the public from high levels of the toxic chemical. EPA’s current reference dose for methylmercury, established in 1995, is 0.1 microgram per kilogram of body weight per day — the estimated amount to which an individual can be exposed on a daily basis that is likely to have no adverse health consequences. The agency says the typical American consumer eats less than a third of an ounce of fish per day, and with that amount would be exposed to considerably less methylmercury than its current guideline.

Based on an analysis of available data that included exposures to methylmercury and food-consumption surveys, a Research Council committee concurred that the majority of Americans are at low risk of adverse health effects. But while most people are relatively safe, the committee estimated that as many as 60,000 children may be born each year in the United States with neurological problems because of exposure to the chemical in utero. Children of women who consume large amounts of fish and seafood during pregnancy are at special risk of neurological damage that could lead to poor performance in school.

To draw its conclusions, the committee evaluated the range of data on which risk assessments conducted by EPA and others are based. It also reviewed new findings that have emerged since the development of EPA’s current reference dose and met with researchers of major ongoing population studies. While the overall weight of the evidence led the committee to conclude that the current guideline is scientifically justifiable, it recommended changes to how the guideline is determined.

When EPA developed its guideline five years ago, it considered data from a 1971 Iraqi poisoning incident to be the most relevant. However, to ensure that the agency uses the most appropriate data when it revises the reference dose, the committee analyzed more recent population studies in the Faroe Islands, Seychelles Islands, and New Zealand. It concluded that EPA should use the Faroe Islands as the critical study for deriving the reference dose.

The committee found that neurodevelopmental problems are the most appropriate basis for setting an exposure limit, but researchers still need to find out if there is a precise time during development when the brain is most sensitive to methylmercury and exactly how the chemical exerts its effects. Evidence also is pointing to possible adverse effects on the cardiovascular and immune systems. Whether methylmercury causes cancer is still not known.

Better data are needed to bring consensus among scientists on how to account for some uncertainties, such as varying individual responses to methylmercury exposure and emerging health concerns. For example, more research on genetics, age, sex, health status, and nutrition — all of which might influence responses — should be conducted. Likewise, data on exposure in different regions of the United States and in specific populations with high consumption of fish should be gathered. Research also should be conducted on other forms of mercury, including the type used in dental fillings to see if and how they affect the human body’s response to methylmercury. — Bob Ludwig

Toxicological Effects of Methylmercury. Committee on Toxicological Effects of Methylmercury, Board on Environmental Studies and Toxicology, Commission on Life Sciences (2000, 368 pp.; ISBN 0-309-07140-2; available from National Academy Press, tel. 1-800-624-6242; $54.00 plus $4.50 shipping for single copies).

The committee was chaired by Robert A. Goyer, professor emeritus, University of Western Ontario, who now resides in Chapel Hill, N.C. The study was funded by the U.S. Environmental Protection Agency.

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