Category Archives: Vaccines
While it has been decades since polio was a critical threat for much of the developed world, the disease—a virus that can spread from person to person and affect the brain and spinal cord with the potential for paralysis—still causes disease and death in the developing world. Earlier this year cases were reported in Syria, while in Israel the polio virus was found in soil likely from human waste infected with the disease, prompting a revaccination campaign among children age 5 and under. Polio has continued to spread in Afghanistan, Nigeria and Pakistan, and has been reintroduced and continues to spread in Chad and in the Horn of Africa after the spread of the virus was previously stopped. Other countries have seen small numbers of cases recently after no cases for decades.
Because even a small spread of the disease could reach the United States if infected individuals carry the virus here, the U.S. Centers for Disease Control and Prevention (CDC) several years ago made polio one focus of their Emergency Operations Center. CDC staff work with the World Health Organization and foreign health departments on vaccination campaigns aimed at fully eradicating the disease.
>>Bonus Content: View the CDC's infographic, "The Time to Eradicate Polio is Now."
NewPublicHealth spoke recently with Sona Bari, senior communications officer at the World Health Organization about the efforts underway to eradicate polio globally.
NPH: How are you able to detect polio outbreaks?
Sona Bari: We have a global surveillance system for polio and know from it that since 1988 the reduction of the disease has been over 99 percent. Polio is now endemic, which means indigenous polio virus transmission has never been stopped in parts of three countries: Nigeria, Afghanistan and Pakistan. So the surveillance is important because you can get polio down to very low levels like you do now, but it can reemerge. To completely eradicate polio you have to have an effective intervention, which is largely by vaccination. And you can be bring polio under very tight control by massive vaccination, but the virus is very good at finding children who are unvaccinated or under-vaccinated, and in Nigeria, Afghanistan and Pakistan we still have large groups of unvaccinated children. So the reason that polio transmission has not been stopped in these areas is that not enough children are vaccinated.
NPH: Why is there insufficient vaccination in those countries?
Bari: The basic reason is the quality of vaccination activities. Do these countries have decent health systems—strong routine immunization systems where children are regularly taken to a medical facility for their immunizations? When there are mass vaccination campaigns, are we reaching all children? Then there are, on top of that, layers of political complexities. In one part of Pakistan, for example, there is a ban on polio vaccinations by the local warlords. So there are access and security issues, layered on top of the difficultly of reaching all who need vaccines in countries such as Nigeria or Pakistan. That said, we know that these circumstances are not unique. They may differ from country to country, and each country does have a unique combination of the obstacles, but polio has been eradicated in countries that are far poorer than Nigeria or Pakistan, that have had worse conflict and that have perhaps much worse health systems. So it can be done.
Youth Smoking Rates Reach Record Lows in 2013
Overall youth smoking declined significantly in 2013, and smoking rates fell to record lows for all three grades surveyed (grades 8, 10 and 12), according to the Monitoring the Future survey released annually by the National Institute on Drug Abuse and conducted by researchers at the University of Michigan’s Institute for Social Research. For all three grades combined, the percentage of students who reported smoking cigarettes in the past month fell from 10.6 percent in 2012 to 9.6 percent in 2013. The data is based on annual surveys of 40,000 to 50,000 students in about 400 different secondary schools. Read more on tobacco.
WHO and UNICEF Vaccinating Millions of Children in the Middle East Against Polio
The World Health Organization (WHO) and UNICEF are mounting the largest-ever immunization response in the Middle East, with a goal of vaccinating more than 23 million children against polio in Syria and neighboring countries over the next few weeks. The campaign is in response to an outbreak of polio in Syria, where 17 cases have so far been confirmed, and to the detection of the virus in sewage in other parts of the Middle East.
The campaign plans to vaccinate all children under age 5 in the targeted areas in the next few months, whether they are living at home or displaced by conflict. The vaccinations will be given at set sites or by workers going house to house, and the campaign will be carried out by national and local health authorities supported by UNICEF, WHO, the Syrian Arab Red Crescent and other partners. The total cost to UNICEF and WHO through April 2014 will be $39 million.
Prior to this outbreak, no polio cases have been recorded in Syria since 1999. The risk of spread to countries in the region and beyond is considered high, and health authorities from 21 countries have declared a public health emergency. Genetically-related polioviruses, which originated in Pakistan, were found in sewage samples in Egypt in December 2012 and in Israel in the West Bank and Gaza earlier in 2013. According to WHO, immunization activities have been significantly constrained in Syria in the past few months by the ongoing conflict, which has led to 500,000 to 700,000 children missing vaccinations.
Editor’s Note: NewPublicHealth also spoke with Sona Bari, WHO's senior communications officer, about the efforts underway to eradicate polio globally. The interview will run later today.
Read more on global health.
CDC Expects TB Test Shortage to Ease
Supplies of tuberculin skin tests are expected to return to normal in January, following shortages that health providers have been experiencing since 2012, according to the U.S. Centers for Disease Control and Prevention (CDC). Two tests are approved by the U.S. Food and Drug Administration to detect tuberculosis and diagnose active illness: Tubersol, made by Sanofi Pasteur Limited; and Aplisol, produced by JHP Pharmaceuticals, LLC. Shortages were first reported for Tubersol, which was out of production from late 2012 through April 2013, increasing the demand for Aplisol. In August, a CDC survey found 29 of 52 U.S. jurisdictions were reporting a shortage of at least one of the tests. Read more on the Centers for Disease Control and Prevention.
Epidemic of E. coli Infections Traced to One Strain of Bacteria
In the past decade, a single strain of E. coli, has become the main cause of bacterial infections in women and the elderly by invading the bladder and kidneys, according to a study published in the American Society for Microbiology's journal mBio. Besides becoming more resistant to antibiotics, the H30-Rx strain gained an unprecedented ability to spread from the urinary tract to the blood, leading to sepsis and posing a threat to the more than 10 million Americans who annually suffer from urinary tract infections. The study authors say the new findings could help trace the history of the “superbug” and possibly lead to the development of a vaccine. Read more on infectious disease.
A new study published recently in the American Journal of Public Health finds that non-medical exemption laws for vaccines required for school or daycare admission have significantly impacted the vaccination rates of at least one disease. The researchers reviewed relevant laws and regulations for each year between 2001 and 2008 and rated them on their restrictiveness in granting exemptions. The study was funded by a grant from the Public Health Law Research program, a national program of the Robert Wood Johnson Foundation.
According to the study, state laws that make it difficult for children to be exempted from vaccines on religious or philosophical grounds could reduce the number of whooping cough cases, but did not have an impact on cases of measles, mumps, haemophilus influenza type B (Hib) or Hepatitis B.
“Our research shows that during the study period, if all states increased the restrictiveness of their non-medical exemption laws by one level, the number of U.S. whooping cough cases would decline by 1.14 percent, resulting in 171 fewer cases per year,” according to study author Y. Tony Yang, ScD, MPH, associate professor at the College of Health and Human Services at George Mason University.
The study found that the impact on whooping cough may be greater than for the other diseases studied simply because whooping cough affects more people. Researchers call this a “threshold effect,” which means laws may not have a significant impact unless they works to prevent a disease that affects a critical mass of people. During the study period, whooping cough was much more prevalent than the four other diseases studied—the average incidence rate for whooping cough was 18 per 100,000 individuals from 2001 to 2008. For Hib, Hepatitis B, measles, and mumps, the mean incidence rates were less than 1 per 100,000.
A new report from Trust for America’s Health finds that despite recommendations by medical experts about the effectiveness and safety of vaccines, an estimated 45,000 adults and 1,000 children die from vaccine-preventable diseases each year in the United States.
NewPublicHealth spoke with Litjen (L.J) Tan, MS, PhD, chief strategy officer of the Immunization Action Coalition, to ask about ongoing efforts to improve immunization rates among all age groups across the nation. The Coalition works to increase immunization rates and prevent disease by creating and distributing educational materials for health professionals and the public and facilitates communication about the safety, efficacy, and use of vaccines within the broad immunization community of patients, parents, health care organizations, and government health agencies. The Coalition is supported by the U.S. Department of Health and Human Services.
NewPublicHealth: What are the critical gaps in immunization in the United States—for children and adults?
Litjen Tan: Immunization rates are really high in our childhood population, but generally not at all high in the adult population, though for some vaccines the rates are improving. We are also not doing very well for adolescents. On the broader level I think what the immunization rates reflect is the state of preventive care in the United States when you come out of childhood, which is why I think the Affordable Care Act really is a great boon. We’ve got this wonderful preventive care model for our kids; we take our kids in, we get them their shots, they get protected and we’ve got high coverage rates generally over 90 percent for all major vaccines. We have almost no vaccine-preventable disease in the United States except for instances linked to pockets of populations that haven’t been vaccinated—as we’ve seen recently with measles.
But then we get to adolescence we have this breakdown. Rates for HPV vaccination are not so good. Our meningococcal vaccination rates are not where they should be and neither are the tetanus, diphtheria and pertussis booster rates in adolescents. What happens with the adolescents is parents don’t necessarily bring them in for prevention checkups anymore. We bring them in when there’s a problem or when they need a school sports visit, and so we plant in adolescents this idea that care is no longer about prevention but care is now about acute care, and that persists into adulthood. This is the thinking that stops us from saying, “hey, do I need my vaccines? When should I get them?”
We need to make sure that our adolescents get the idea that vaccines prevent disease and that they actually do have vaccines that are recommended for them and then I think we’ll begin to see an appreciation of immunizations for adults as well.
NPH: Do we need to target both parents and the adolescents themselves?
Tan: Absolutely, but there’s a lot of discussion about how we do that. It gets a little tricky because we push autonomy of the adolescent, and we have a precedent in public health—discussions between providers and adolescents about sexually transmitted infections—but there are a lot of legislative and regulatory barriers against directly talking to an adolescent in the absence of a parent.
New reports from the U.S. Centers for Disease Control and Prevention (CDC) show that 39 percent of adults and 41 percent of children six months and older got their flu shots for the 2013-2014 season by early November—a rate similar to flu vaccination coverage last season at the same time.
Other flu shot statistics of note this year include:
- Vaccination among pregnant women (41 percent) and health care providers (63 percent) is about the same as it was this time last year
- High rates were seen again this year among health care providers including pharmacists (90 percent), physicians (84 percent) and nurses (79 percent), but the CDC reported much lower vaccination rates among assistants or aides (49 percent) and health care providers working in long-term care facilities (53 percent)
“We are happy that annual flu vaccination is becoming a habit for many people, but there is still much room for improvement,” says Anne Schuchat, MD, director of the National Center for Immunization and Respiratory Diseases at CDC. “The bottom line is that influenza can cause a tremendous amount of illness and can be severe. Even when our flu vaccines are not as effective as we want them to be, they can reduce flu illnesses, doctors' visits, and flu-related hospitalizations and deaths.”
Seasonal influenza activity is increasing in parts of the United States. Further increases in influenza activity across the country are expected in the coming weeks. “If you have not gotten your flu vaccine yet this season, you should get one now,” said Schuchat.
The CDC’s report comes just ahead of the observance next week of National Influenza Vaccination Week (NIVW), which is scheduled each year for the second week in December because vaccination rates tend to fall off toward the end of November. It’s hardly too late to get the flu vaccine: flu season usually peaks January through March, and the virus—and the potential to catch it—often lasts as late as May.
People who haven’t had the flu shot should make it a priority to do so as soon as possible for at least two reasons. One, providers tend to return their unused vaccines toward the end of the year, which can make it hard to find a vaccine if you still need the shot (check this flu vaccine finder for providers in your area, and call ahead to be sure they have supplies on hand). Two, it takes two weeks for the flu vaccine to take full effect, so the sooner you get it the more protected you are against people harboring the flu during the upcoming holiday party season.
Still on the sidelines about getting the shot? The CDC has some impressive numbers from last year’s flu season: flu vaccination prevented an estimated 6.6 million influenza-associated illnesses and 79,000 hospitalizations during the 2012-2013 flu season.
>>Bonus Links: Learn more about preventing and treating influenza on NewPublicHealth.
>>Bonus Content: CDC's infographic on the benefits of the flu vaccine (full size PDF).
Chicago Announces Trio of Anti-tobacco Initiatives to Curb Youth Smoking
The city of Chicago and Mayor Rahm Emanuel this morning announced a trio of anti-tobacco initiatives designed to reduce youth access to tobacco. The first would regulate e-cigarettes as tobacco products, while the second would restrict the sale of flavored tobacco products near schools and the third would work to educate the public on the dangers of menthol-flavored cigarettes. Further details:
- By defining “tobacco products” as products that are made of tobacco or include tobacco-derived nicotine, the city would be able to regulate e-cigarettes as they do any other tobacco product. This would mean that under the Chicago Clean Indoor Air Act, e-cigarette use would be restricted everywhere where smoking is restricted, including almost all public places and places of employment.
- Flavored tobacco products, including menthol products, could not be sold within 500 feet of schools, and existing stores would not be grandfathered in. This would be the first regulation of menthol-flavored cigarettes anywhere at the federal, state or local levels.
- Understanding that menthol-cigarettes are often—and wrongly—viewed as less unhealthy than other tobacco products, as well as that fact that the flavoring makes them more appealing to kids, the city is launching a public service advertising campaign on the realities of the products.
“E-cigarettes, as well as flavored products, are gateway tobacco products targeted at our kids,” said Emanuel. “The tobacco industry has spent years developing products that are aimed at hooking our youth on nicotine and getting them smoking for their entire life.” Read more on tobacco.
FDA to Investigate Reports on Weight-related Problems with the Morning-After-Pill
Following yesterday’s report that the European equivalent of the Plan B One-Step “morning after pill,” Norlevo, is less effective for women who weigh 165 pounds or more and ineffective for women who weigh 176 pounds or more, the U.S. Food and Drug Administration (FDA) has announced it will perform its own investigation into the product. The agency is "currently reviewing the available and related scientific information on this issue, including the publication upon which the Norlevo labeling change was based," said FDA spokeswoman Erica Jefferson said in a Monday statement. "The agency will then determine what, if any, labeling changes to approved emergency contraceptives are warranted." By law, the morning-after pill is available to all U.S. women of child-bearing age, over the county and with no point-of-sale restrictions. Read more on sexual health.
Concerns Over Cost, Sexual Activity Keep Many Parents From Having Kids Vaccinated Against HPV
Costs and parental concern over their kids’ sexual activity may be the reason that so view children—both girls and boys—are not being vaccinated against the human papillomavirus (HPV), according to a new review of 55 studies appearing in JAMA Pediatrics. HPV vaccines protect against the strains of genital warts that cause approximately 70 percent of cervical cancers, and they are recommended for girls aged 11 to 12. Boys are recommended to receive the vaccine as young as age 11, as it protects not just against genital warts, but also oral, penis and rectal cancers. However, the review found that many parents put off the vaccination either because they believe their child is not sexually active—so doesn’t “need” the vaccine—or because they fear it will encourage them to become sexually active. Researchers determined that a physician’s recommendation was one of the strongest motivators toward deciding to accept the vaccination, although this did not happen nearly enough. The researchers recommended improving these statistics by educating doctors and parents on the importance of the vaccine. Read more on cancer.
FDA Approves Vaccine for H5N1 Strain of Avian Flu
The U.S. Food and Drug Administration (FDA) has approved the first adjuvanted pandemic influenza vaccine for the prevention of the H5N1 strain of the avian flu, also known as bird flu. While most influenza A viruses do not infect people, H5N1 does and has demonstrated a 60 percent mortality rate when a person becomes infected. The U.S. Department of Health and Human Services has added the vaccine to the National Stockpile. “This vaccine could be used in the event that the H5N1 avian influenza virus develops the capability to spread efficiently from human to human, resulting in the rapid spread of disease across the globe,” said Karen Midthun, MD, director of the FDA’s Center for Biologics Evaluation and Research. “Vaccines are critical to protecting public health by helping to counter the transmission of influenza disease during a pandemic.” Read more on infectious diseases.
Study: Excessive Television Watching Equals Excess Weight in Kids
Children and teenagers who spend excessive amounts of time watching television or in front of other screens are also more inclined to be overweight or obese, according to a new study in the journal Pediatrics. Researchers analyzed data on nearly 8,000 boys and girls, ages 9-16, finding that each additional hour a day spent watching television was linked to a body mass index (BMI) scale increase of about 0.1 points, or about half a pound. Kids who watch television or play video/computer games are not only for the most part physically idle, but also more likely to snack. While many parents believe their kids spend a reasonable amount of time in front of screens, the reality is that most kids in the United States and Canada surpass the recommended daily limit of two hours. "We don't pay attention to the fact that it's half an hour here, half an hour there, an hour here, an hour there," said Mark Tremblay, director of Healthy Active Living and Obesity Research at the Children's Hospital of Eastern Ontario Research Institute in Ottawa, Canada, who was not a part of the study. Read more on obesity.
Study: One in 10 U.S. Kids has ADHD
About one in 10 U.S. children have attention-deficit/hyperactivity disorder (ADHD), according to a new study in the Journal of the American Academy of Child and Adolescent Psychiatry. A 2011 poll of more than 95,000 parents found 11 percent of kids ages 4-17 had ADHD, up from 9.5 percent in 2007. The number of kids on ADHD medication also climbed about 1 percent, with research showing that half the kids with ADHD are diagnosed before the age of 6. "This finding suggests that there are a large number of young children who could benefit from the early initiation of behavioral therapy, which is recommended as the first-line treatment for preschool children with ADHD," study author and U.S. Centers for Disease Control and Prevention (CDC) researcher Susanna Visser. The study also found that while the number of kids with ADHD is still climbing, it is no longer climbing as fast—the rate was increasing about 6 percent a year in the mid-2000s, but was only 4 percent a year from 2007 to 2011. Read more on pediatrics.
The flu season is pretty mild so far. The latest FluView report from the U.S. Centers for Disease Control and Prevention (CDC) shows that the current rate of flu cases across the country is below other years, and some states have yet to see any flu cases at all. But health experts worry those reports will make people who still haven’t gotten the vaccine complacent about getting their shot. And going without poses the risk of a multi-day illness; transmitting the flu to other people who may be more vulnerable to the virus than you; and the potential for serious side effects such as pneumonia and—in rare cases—death.
If you’re still shotless, health experts advise you to roll up your sleeves by Wednesday if at all possible. Here’s why: Immunity to the flu can take up to two weeks after you’ve received the injection. Get the shot by this Wednesday, November 13, and you’ll be protected by the day before Thanksgiving.
That’s the heaviest U.S. travel day of the year, when the possibility of encountering people with the flu at airports, train stations, or even at Thanksgiving dinner greatly increases.
“Visiting mom, grandma and that new baby can make for memorable holiday moments, as long as you don't bring the flu virus along to spoil the party,” says Jeff Golden, spokesman for the Madison, Wisc., health department which, like many other health departments, has sent out recent flu advisories.
CDC research adds another reason to get the shot this week. The agency has found that the momentum to get the flu vaccine wanes after Thanksgiving, perhaps because people assume that as the weather gets colder, if they haven't gotten influenza yet, they won’t. But that’s foolhardy thinking. The U.S. flu season runs from September through April, and the worst of it often hits in January and February. If you wait until cases increase, you may find that you don’t have enough time for the shot to protect you. And you may also find it hard to locate supplies of the vaccine. Knowing that interest in the shot drops after Thanksgiving, private and public clinics, as well as doctors’ offices, often return unused supplies toward the end of the year to free up storage space and in some cases get a refund on the unused doses. Health departments may then keep supplies centrally, but that location may not be convenient.
Wonder where to get the flu shot? Here are good ideas:
- Key in your zip code at flu.gov
- Dial 211, a resource for local services in many communities
- Check pharmacies to see if they have supplies on hand and what hours they give the shots
- Call your local health department to ask if they have clinic hours for the flu vaccination
- Key in “travel clinic” on a search engine to find private clinics in business districts, but call ahead to check on supplies and hours
Health departments may give the shot for free, or ask for payment on a sliding scale based on income. Pharmacies charge about $25, and private doctors’ offices may add a $10 or $20 administrative fee on top of that. The cost is typically covered by insurance, though you may have to file the paperwork yourself.
HPV Vaccines Less Effective in African-American Women than in White Women
Perhaps because of their lower participation rates in clinical trials, African-American women are less likely to benefit from available human papillomavirus (HPV) vaccines that guard against cervical cancer, according to new findings presented at the 12th annual International Conference on Frontiers in Cancer Prevention Research. The two most popular vaccines in use protect against infection by HPV 16 and HPV 18, which are responsible for about 70 percent of cervical cancers. However, these two subtypes are half as likely to be found in black women as they are in white women. Researchers found that the most common infections for white women are from subtypes 16, 18, 56, 39 and 66; the most common for black women are 33, 35, 58 and 68. "Since African-American women don't seem to be getting the same subtypes of HPV with the same frequency, the vaccines aren't helping all women equally," said study author Adriana Vidal, Ph.D., assistant professor of obstetrics and gynecology at Duke University School of Medicine. Read more on health disparities.
San Francisco Proposes Tax on Soda, Other Sugary Beverages
In an effort to curb the growing rate of obesity and obesity-related health issues, a San Francisco, California city supervisor has proposed a ballot measure that would impose a 2-cents-per-ounce tax on soda and other sugary beverages with at least 25 calories per ounce. This would be the first and strongest such city measure in the country, amounting to an additional 24 cents for a normal 12-ounce can of soda. Supervisor Scott Wiener said the tax proceeds, which he estimates would be $30 million annually, would go toward physical education and healthy lunch programs in city schools, as well as city parks, recreation programs and community health organizations. The California cities of Richmond and El Monte last year failed to enact similar taxes. A ballot measure requires a two-thirds majority to pass. "We know that this will be a long road," said Wiener. "This type of proposal has occurred in other cities and the beverage industry always comes out full guns blaring, so we're going to need to pull together to make sure that this wins." Read more on obesity.
Study: Young Cancer Patients at Increased Risk for Suicide
The stress of a cancer diagnosis means that teens and young adults who are diagnosed should be carefully monitored for behavior changes and other issues that could be a sign of suicidal thoughts, according to a new study in the Annals of Oncology. While there is an elevated risk of suicide for cancer patients of all ages, “because adolescents and young adults are still developing their coping strategies for stress, they may be more affected than adults when facing major adversity such as a cancer diagnosis," said lead researcher Donghao Lu, from the department of medical epidemiology and biostatistics at the Karolinska Institute in Stockholm, Sweden. Lu and his team found that Swedes ages 15-30 with a cancer diagnosis were at a 60 percent greater risk of suicide or attempted suicide, compared to people in the same age group but without cancer; in the first year after the diagnosis the risk was 150 percent higher. Lu said the findings indicate the need for greater communication and cooperation among medical professionals, psychological professionals, family members and social workers. Read more on cancer.
In honor of World Polio Day, the U.S. Centers for Disease Control and Prevention (CDC) will highlight polio eradication work around the globe on Twitter and Facebook. Development of the polio vaccine has reduced the disease worldwide by 99 percent, with only Afghanistan, Nigeria and Pakistan as the remaining polio endemic countries in 2012.
But both in endemic countries and in countries where polio was thought to have been vanquished, cases persist. According to the Global Polio Eradication Initiative, just this week eleven new wild poliovirus (WPV) cases were reported, including one from Afghanistan, two from Ethiopia, four from Pakistan and four from Somalia. The total number of WPV cases for 2013 is now 296, with 99 from countries that have not yet been able to eradicate the disease and 197 from countries that have seen outbreaks. In Israel, for example, while no cases of paralytic polio have been reported, environmental surveillance suggests that virus transmission (first detected in February 2013) continues in parts of the country’s southern and central regions. A vaccination campaign for children under age ten is ongoing.
On December 2, 2011, CDC Director Thomas R. Frieden, MD, MPH, activated CDC’s Emergency Operations Center (EOC) to strengthen the agency’s partnership engagement through the Global Polio Eradication Initiative (GPEI). Activation of the EOC has provided enhanced capacity for CDC’s polio eradication support program, which trains public health volunteers in the United States and globally to improve polio surveillance and help plan, implement and evaluate vaccination campaigns.
Additional EOC activities include:
- Publication of several joint World Health Organization Weekly Epidemiologic Record/CDC Morbidity and Mortality Weekly Reports (MMWR) highlighting polio eradication progress.
- Collaboration with GPEI partners on detailed country-plans for expanded technical and management support, including assistance with outbreak responses, surveillance reviews, vaccination campaign planning and monitoring, and data management.
- Provision of operational support to Nigeria for the country’s FY 2012 Polio Eradication Emergency Response Plan. The plan focuses on enhancing management and leadership skills to improve program performance.
- The development of indicators for monitoring polio vaccination campaign performance in the areas of planning, implementation and evaluation.
- Review of WHO-proposed outbreak response protocols for all polio-affected countries.
“If we fail to get over the finish line [to fully eradicate polio],” says Frieden, “we will need to continue expensive control measures for the indefinite future…More importantly, without eradication, a resurgence of polio could paralyze more than 200,000 children worldwide every year within a decade.”