Across battle lines drawn decades ago, the fighting has lately become intense. If you're the parent of young children, you can hardly fail to have noticed. All that smoke and fire around you is the heating up of childhood vaccination issues.
On one side are the government and the pediatrics community, seeking to inoculate as many children as possible to keep childhood diseases at bay. On the other are activists who say that vaccine risks are underplayed and that the blanket rules that cover most childhood immunizations jeopardize some children whose genetic differences or undetected medical problems put them at higher risk of serious side effects.
Recent events--widely reported in the news and on Internet sites--have fueled the combat. These include:
* the withdrawal last year of Rotashield, a vaccine to prevent some diarrheal diseases, after the vaccine was linked to intestinal blockages in a small number of babies;
* a congressional hearing last spring into a purported link between the measles/mumps/rubella (MMR) vaccine and autism;
* a decision, prompted in part by activist lobbying, to remove the mercury-based preservative Thimerosol from all childhood vaccines by April 2001, because in large doses mercury can cause neurological disorders; and
* recent outbreaks, largely among nonimmunized populations, of polio in the Caribbean and rubella in Nebraska.
The crossfire has sent armies of parents fleeing . . . to the Web. As if there were refuge there. Instead, they find government, pediatric organization and university Web sites that generally favor all pediatric vaccinations and downplay or refute side effects and negative reactions. And they find activist sites that cite alarming facts and theories about the harm vaccines can cause.
No wonder so many parents are confused about whom to trust. A study in the November issue of Pediatrics found that 25 percent of parents surveyed believe (wrongly) that childhood vaccines can weaken their children's immune systems. But the same study also found that a substantial number of parents said they consider the National Resource Organization for Immunization Information--a fictitious organization made up by the study authors--to be a reliable source of information.
The chart on the facing page is our attempt to clarify battle lines in the vaccine war. Vaccine by vaccine, and issue by issue, it presents a capsule view of the two camps' positions, and the facts, as near as anyone can tell them.
What adds to the confusion is that you can't just dismiss all the activists' concerns. Some past efforts by activists have benefited children's health by forcing a closer examination of safety issues, a point the activists often note. Partially credited to their efforts have been a change four years ago in the United States to a safer diphtheria/tetanus/pertussis vaccine and a switch to inactivated polio vaccine from a live-virus vaccine that had been implicated in some rare cases of polio.
Differences between the two sides are often hard to referee. Activists and health officials often look at identical data and come up with disparate conclusions. Just a few weeks ago, a study in the Journal of the American Medical Association (JAMA) examined side effects of the chickenpox vaccine that had been reported to the Food and Drug Administration (FDA).
According to the study, the FDA's Vaccine Adverse Events Reporting System (VAERS) received 6,574 case reports of adverse events in children who received the vaccine, a rate of 67.5 reports per 100,000 doses sold. Approximately 4 percent of these reports described serious events, including 14 deaths. After reviewing the data, FDA researchers concluded that most of the reactions were minor, and serious risks appeared rare. They also said they could not confirm that most of the reported serious side effects had actually been caused by the vaccine.
But Barbara Loe Fisher, executive director of the National Vaccine Information Center (NVIC), founded by parents who say their children were harmed by an older version of the diphtheria/tetanus/pertussis vaccine that is no longer in use, takes issue with the researchers' conclusions. "We have been getting reports from parents that their children are suffering high fevers, chickenpox lesions, shingles (herpes zoster), brain damage and dying after chickenpox vaccination," says Fisher.
An underlying problem may be not the interpretation of the data, but rather the data themselves. Under current rules, physicians and even parents are asked to report any problem they believe may have been caused by the vaccine--no matter how probable or improbable this may be. A broken leg associated with the chickenpox vaccine? Paul Offit, head of the Vaccine Education Center at Children's Hospital of Philadelphia, says the FDA received one such report. All reports are sent to the VAERS and many end up on vaccine package inserts as well.
An even hotter topic has been whether the MMR vaccine can cause autism. The question drew particular attention after Rep. Dan Burton (R-Ind.), whose grandson was diagnosed with autism after getting his MMR vaccine, held congressional hearings earlier this year on the possible vaccine-disease connection. Some vaccine activists based their claim of a connection on a small 1998 Lancet study by a Scottish researcher who found that eight of 12 previously healthy London children developed stomach problems and autistic behavior after receiving the vaccine.
But the Centers for Disease Control and Prevention (CDC) notes that a larger 1999 study, also published in The Lancet, found no increase in the number of autism spectrum disorders (ASD) in London children that could be correlated to the introduction of the MMR vaccine in 1988. And while a small study published in September in the journal Gastroenterology shows that traces of MMR vaccine virus are found in the intestines of autistic children but not found in children who have not been diagnosed with autism, an editorial in the same issue of the journal says the study did not prove an association between the virus found and the diagnosis of autism.
Some vaccine activists have proposed unbundling combination vaccines such as MMR and giving each at a separate visit to reduce risks. But such vaccines are rarely sold to doctors in unbundled form. And public health groups say there's no evidence that combination vaccines increase risk. Combining vaccines, they add, cuts costs, reduces doctor visits and lessens the likelihood of missing doses.
Parents' confusion is not a trivial matter to public health officials. Bruce Gellin, lead author of the November Pediatrics study and head of the National Network for Immunization Information, a new education group in partnership with several health care professional organizations, explains pediatric leaders' concern, warning, "Even a small drop in the immunization rate may lead to a resurgence of infectious diseases that are currently nearly eliminated from the U.S."
Could that happen? Yes. But a major return of childhood diseases hasn't materialized yet in the United States. The rates of childhood vaccinations have never been higher, according to the CDC. In 1999 the overall immunization rate for U.S. preschoolers was 80 percent. But recent sporadic outbreaks of measles and pertussis--particularly pertussis, also known as whooping cough--have health officials concerned.
Some states, including Maryland and Virginia, have seen a slight rise in pertussis cases in the last couple of years--although whether that's the result of falling child immunization or waning adult immunity is not clear. While the respiratory disease is usually fairly mild in older children and adults, babies under 6 months old can die because their tiny airways become too blocked to breathe. Since infants can't receive their first of three pertussis vaccinations until they are 6 months old, contracting pertussis from an older sibling who has not been immunized can prove fatal.
In Virginia the number of pertussis cases has nearly doubled, from 56 in 1998 to 106 so far this year. Some of those cases are in nonimmunized children, says Milton Jackson, deputy director of the division of immunization at the Virginia Department of Health. The Maryland Department of Health reported 124 cases of pertussis last year, up 88 percent from the 66 cases reported in 1998. According to health department records dating back 10 years, the highest number of cases was seen in children under 7 months old.
To be fair, most vaccine activist groups don't flat-out oppose vaccination. "We are not anti-vaccine," says the NVIC's Fisher. "We just want to see a change in the 'one size fits all' approach that assumes that all kids can get the same vaccines and react identically."
Quite a few changes are afoot. The CDC's Advisory Committee on Immunization Practice will consider studies this year that show it may be possible to drop one out of four polio shots without compromising a child's immunity.
And just two weeks ago the National Institutes of Health (NIH) and the FDA sponsored a joint conference to discuss vaccine safety issues. Proposals included larger clinical trials, to help prove safety as well as effectiveness, and additional safety monitoring both before and after a vaccine becomes available.
At an NIH meeting in November, researchers heard a presentation on the possibility of removing one of the five shots now given to prevent diphtheria, pertussis and tetanus. One fewer shot may decrease the sore, red arms suffered by about 15 percent of kids who get the fifth dose of the vaccine without sacrificing full immunity, says David Klein, an NIH program officer who convened the meeting.
Is there anything you can do to simultaneously protect your child both from dread diseases such as polio and the very rare instances of vaccine side effects? Not really. Physicians generally don't immunize kids who have very serious illnesses, but other than that, they don't really know who is likely to suffer a severe reaction. However, says Gellin, we also don't generally know which kids, if left unimmunized, are likely to suffer complications from childhood diseases.
While most states require that your child be fully immunized in order to attend school and, usually, day care, most states including Virginia and Maryland, as well as the District of Columbia, allow parents to avoid this requirement if they have a philosophical or religious objections to vaccines. But that brings its own, perhaps greater, risks. A recent study published in JAMA found that children whose parents had registered objections to the MMR vaccine were 35 times more likely to get measles, which can produce complications including croup, bronchitis, hepatitis, encephalitis, and pneumonia.
And with all the concern over vaccines these days, parents can't necessarily assume that their child will be protected from diseases because everyone else at school has been vaccinated. A nurse at a private school in Montgomery Country says in her eight years at the school she usually sees no more than one child each term who is not vaccinated because their parents took an exemption. This year she has two.
Can you really count on your neighbors' kids' immunity to protect your kids? Gellin likens it to a four-way stop sign. "You can run that stop sign if you are certain that everyone else will stop. If someone else runs their stop sign, too, however, you may be in big trouble."
RESOURCES
* National Immunization Program (Centers for Disease Control and Prevention): www.cdc.gov/nip
* National Vaccine Information Center Parent Advocacy Group: www.909shot.com
* Children's Hospital of Philadelphia: www.vaccine.chop.edu. This site is maintained by Paul Offit, a member of CDC's Advisory Committee on Immunization Practice.
* Vaccine Safety Institute at Johns Hopkins University School of Public Health: www.vaccinesafety.edu
* Immunization Action Coalition: www.immunize.org. This group promotes vaccinations to communities, families and physicians. Some of the coalition's funding comes from the CDC.
* National Network for Immunization Information, an education group sponsored by the American Academy of Pediatrics and other health care groups: www.immunizationinfo.org
TRADING SHOTS: Activist and Government Positions on Vaccines
In an effort to help parents untangle the thickening weave of vaccine safety information and misinformation available online and through various news outlets, this chart presents, in highly simplified and condensed form, a snapshot of the contesting views on the risks associated with the major childhood inoculations. The chart should not be considered comprehensive. For further information about individual concerns and your own child's specific risks, consult your doctor.
* DTaP (Diptheria/Tetanus/Pertussis) Vaccine:
Activists' Charges: National Vaccine Information Center cites anecdotal evidence to support its claim that DTaP causes rare cases of death, brain damage and illness. But it concedes DTaP causes far fewer side effects than the old DPT vaccine, which it replaced in 1996.
Government Response: CDC says that no studies have proved a link between either DPT or the newer DTaP and death and permanent brain damage.
Notes: The most common side effect is a red and swollen arm at fifth dose, given between ages 4 and 6. Studies suggest this dose could be eliminated without compromising childhood immunity. (CDC may review data this year; agency may also consider adding adult booster to ensure immunity continues.)
* Chickenpox Vaccine:
Activists' Charges: NVIC draws on Journal of the American Medical Association study this year that reported a 4 percent rate of serious side effects ranging from anaphylaxis (severe allergic shock) to death.
Government Response: FDA researchers who analyzed the data and wrote the JAMA study offer a different interpretation. They say most side effects were minor and the serious risks appear to be rare. Authors said they could not confirm causal link between vaccine and these serious events.
Notes: Part of impetus for vaccine approval was to save parents from losing a week of work if kids got chickenpox. Use of vaccine is so widespread in the U.S. that an unvaccinated child is not likely to contract disease before adulthood. But anyone who hasn't had the disease should have the shot eventually or risk serious side effects of adult cases.
* MMR (Measles/Mumps/Rubella) Vaccine:
Activists' Charges: NVIC cites small 1998 Lancet study by a Scottish researcher who found eight of 12 previously healthy children developed stomach problems and autisticbehavior after receiving the vaccine. Five of the eight had had previous adverse reactions to other vaccines.
Government Response: CDC notes a that larger 1999 study, also published in The Lancet, found no increase in the number of autism spectrum disorders (ASD) in London children that could be correlated to the introduction of the MMR vaccine in 1988.
Notes: Better documented and more common MMR reactions include soreness, redness and localized swelling. About 5 to 15 percent of immunized kids develop a fever of over 103 degrees that lasts for a few days, beginning 7-12 days after injection. Report any concern to your physician.
* Vaccines and Diabetes:
Activists' Charges: NVIC cites a 1997 study in Infectious Diseases in Clinical Practice linking the introduction of three new vaccines in Finland to a 147 percent increase in diabetes in children 4 and under. In children 5 to 9, a new vaccine was tied to a 40 percent diabetes rise.
Government Response: Two separate gatherings of infectious disease experts in 1998 found no evidence for increased risk of diabetes from childhood vaccines; more likely factors were genetics and environment and certain infections.
Notes: Some studies seek to determine if certain vaccines might protect high risk children against diabetes, as has been demonstrated in genetically predisposed animals.
* "Hot Lots":
Activists' Charges: NVIC review of data claims some lots of vaccines cause more side effects than others.
Government Response: CDC says FDA-reviewed manufacturer safety tests and FDA inspections of vaccine-manufacturing plants ensure there are no hot lots. To date, no vaccine lot in the modern era has been found unsafe on the basis of reports from the Vaccine Adverse Event Reporting System (VAERS).
Notes: Doctors' offices are required to record the lot number when they give your child a vaccine. Many health experts advise parents to record the lot number along with the vaccine type and date it was given. Should a problem be found with a specific lot, having this number could ease your mind -- or help your doctor find you.
* Thimerosol:
Activists' Charges: NVIC links the mercury in thimerosol, a compound used as a preservative in many childhood vaccines, with neurological problems.
Government Response: CDC and other groups say no evidence ties thimerosol to neurological problems, but have called for all thimerosol-containing vaccines to be off the market by spring 2001.
Notes: Thimerosol-free versions of all vaccines are available, according to the NVIC. Ask your doctor to use one of these instead of one that contains the preservative.
* Hepatitis B:
Activists' Charges: NVIC review of U.S. Vaccine Adverse Events Reporting System database shows 2,424 side effects from the vaccine between 1990 and 1998 and 73 deaths in children under 14. Cites researcher at Duke University who says side effects are underreported because drug studies monitored children for only four to five days, insufficient time to detect automimmune diseases that can be a side effect.
Government Response: CDC finds no association between serious side effects and vaccine after >20 million in the U.S. and >500 million worldwide have received the vaccine; says death is extremely rare. Institute of Medicine analysis of early data found insufficient evidence to link deaths to vaccine. A recent study suggested persons developing rheumatoid arthritis after hepatitis B vaccination were genetically at risk for the disease.
Notes: Babies get the first injection within 12 hours of birth. Three more injections are needed within the next six months to confer immunity. Common side effects noted by the CDC: Up to 1 in 11 patients have soreness at the injection site, and 1 in 14 have a mild to moderate fever.
* Illness in Children:
Activists' Charges: NVIC says since most vaccine trials don't include sick children, no evidence exists that it is safe to vaccinate even mildly ill children.
Government Response: CDC says mild childhood illness doesn't compromise vaccine safety or effectiveness. It counsels parents not to let mild illness make them fall behind on scheduled vaccinations and risk serious disease.
Notes: Parents looking for help in deciding when a sick child should skip a vaccine and when he should not may want to check this page on the CDC Web site: http://www.cdc.gov/nip/recs/contraindications.pdf