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Are vaccines safe? I'm hearing so many different things about vaccines. I don't know whom to believe. Are vaccines effective? Is it true that vaccines can cause side effects? Is it true that polio vaccination causes polio? Can I or my child get AIDS, or HIV, or chronic fatigue syndrome from vaccines? Do vaccines cause fibromyalgia, rheumatoid arthritis, arthritis, or lupus? Who should not have vaccinations? Do vaccines cause autism? Can't I get animal diseases from vaccines that are made using animal cells? Can't I just "wait and see" on my child's vaccinations? Can epidemics occur today? In the United States? Are we safe from epidemics? Why must my child have so many shots? Aren't there some chemicals and other substances added to vaccines? I got the influenza shot and I still came down with the flu. Why? If you didn't find the answer you need in this section...

Are vaccines safe? Yes. Vaccines are tested extensively for safety, prior to approval by the Food and Drug Administration. However, no vaccine is 100% without risk. Although the risk level of vaccines is exceedingly low, efforts are being made to reduce the risk even lower by enhancing surveillance systems, researching vaccine safety, adopting administration policies that are safe, and providing education and information to parents, health care providers, and the general public. Additional vaccine safety information can be found on the NVPO web site at: http://www.cdc.gov/od/nvpo/fs_tableIII_doc1.htm and http://www.cdc.gov/od/nvpo/vacsafe.htm. Table of contents

I'm hearing so many different things about vaccines. I don't know whom to believe. No one knows your health or your child's health better than the health care provider that routinely cares for you and/or your child. All health care providers, who administer vaccinations, are required to discuss the benefits and risks of immunization (using Vaccine Information Statements developed by the Department of Health and Human Services). Therefore, health care providers have a responsibility to provide information that is clear and accurate. To learn more about the benefits and risks of vaccines, you may download the Vaccine Information Statements from the following web site: http://www.cdc.gov/nip/publications/VIS/index.html. Table of contents

Are vaccines effective? Yes. One of the greatest success stories in public health is how vaccines have reduced infectious diseases. Routine immunization has eradicated smallpox from the globe; led to the near elimination of wild poliovirus; reduced preventable infectious diseases to an all-time low; and minimized the number of people that experience the devastating effects of measles, pertussis and other illnesses. Vaccines are highly effective in preventing death and disability. They also save billions of dollars in health costs annually. A decision to vaccinate is a decision to help protect individuals and entire communities from diseases spread by person-to-person transmission. When immunization programs achieve high levels of community immunity, and practical measures to prevent disease outbreaks, the likelihood that an infected person will transmit the disease to a susceptible individual is greatly reduced. For more information on vaccine effectiveness, see "Immunization Concepts" on the NVPO web site at: http://www.cdc.gov/od/nvpo/intro.htm. Table of contents

Is it true that vaccines can cause side effects? Yes. Vaccines can cause side effects or adverse events, especially when vaccines are administered to millions of people. Because individual immune systems react differently, there are rare occasions when people may experience side effects as a result of an immunization, medical procedure, or medication. Side effects, from an immunization, can range from skin redness and warmth (caused by the injection) to more serious effects, including damage of the central nervous system, or death. However, the possibility of such a serious event is extremely small. The risk of contracting a vaccine-preventable disease is far greater than dying from an immunization. For more information on vaccine side effects, visit the National Immunization Program web site at: http://www.cdc.gov/nip/vacsafe/concerns/side-effects.htm. Table of contents

Is it true that polio vaccination causes polio? Yes. In extremely rare cases, Vaccine Associated Paralytic Polio (VAPP) can be caused by one of two types of polio vaccine: Oral Poliovirus vaccine (OPV) and Inactive Poliovirus vaccine (IPV). OPV, which contains live, weakened virus, is administered orally. IPV contains dead virus and is administered through injection. Since 1979, the only indigenous cases of polio reported in the United States were associated with the use of the live OPV. Until recently, the benefits of OPV use (i.e., intestinal immunity, secondary spread) outweighed the risk for VAPP (i.e., one case among 2.4 million vaccine doses distributed). The Advisory Committee on Immunization Practices (ACIP) recommended a sequential vaccine schedule of IPV/OPV (i.e., two doses of IPV at ages 2 and 4 months, followed by two doses of OPV at ages 12-18 months and 4-6 years) to replace the all-OPV schedule and decrease the risk for VAPP, while maintaining the benefits of OPV. The recommendations were officially accepted by the Centers for Disease Control and Prevention and published in January 1997. Since 1997, the global eradication initiative has progressed rapidly and the likelihood of poliovirus importation into the United States has decreased substantially. Also, the sequential schedule has been well accepted, and no decline in childhood immunization coverage has been observed. Based on this data, on June 17, 1999, ACIP recommended an all-IPV schedule for routine childhood polio vaccination in the United States to eliminate the risk of VAPP.  Current recommendations are as follows: ACIP Recommendations for IPV Vaccination of Children: Routine Vaccination � All children should receive four doses of IPV at ages 2, 4, 6-18 months, and 4-6 years. Incompletely Vaccinated Children � The poliovirus vaccination status of children should be evaluated periodically. If children are not adequately protected, they should complete the recommended vaccination series. Scheduling IPV Administration � IPV administration will require additional injections at ages 2 and 4 months until appropriate combination vaccines are available. Interchangeability of Vaccines � If children have begun the poliovirus vaccination series with one or more doses of OPV, they should receive IPV to complete the series. Administration with Other Vaccines � IPV can be administered simultaneously with other childhood vaccinations that are recommended routinely, including: DTP, DTaP, Hib, Hep B, Varicella (Chicken Pox), and Measles-Mumps-Rubella (MMR) Vaccine. ACIP Recommendations for IPV Vaccination of Adults: For most adults, risk of exposure to polioviruses in the United States is minimal. Therefore, routine poliovirus vaccination of U.S. residents (18 yrs. or older) is not necessary. However, certain adults are at greater risk of poliovirus exposure than the general population. Vaccination is recommended for the following cases: Travelers to areas or countries where polio is epidemic or endemic. Members of communities or specific population groups with disease caused by wild polioviruses. Laboratory workers who handle specimens that might contain polioviruses. Health-care workers who have close contact with patients who might be excreting wild poliovirus. Unvaccinated adults whose children will be receiving OPV. Precautions and Contraindications IPV should not be administered if persons have experienced a severe allergic (anaphylactic) reaction after a prior dose of IPV or to streptomycin, polymyxin B, or neomycin. Although vaccinations for pregnant women should be avoided, IPV can be administered (in accordance with the recommended schedules) if a pregnant woman is at greater risk for infection and requires immediate protection against polio. IPV is the only vaccine that is recommended for vaccination of immunodeficient persons and their household contacts. The following are not contraindications for vaccination: Breastfeeding A child who has diarrhea Minor upper respiratory illnesses with or without fever Mild to moderate local reactions to a previous dose of vaccine Current antimicrobial therapy The convalescent phase of an acute illness ACIP Recommendations for OPV Vaccination: OPV is the vaccine of choice to control polio outbreaks. Unvaccinated children who will be traveling in less than 4 weeks to areas where polio is endemic. If OPV is not available, IPV should be administered. Children of parents who do not accept the recommended number of vaccine injections. These children may receive OPV only for the third or fourth dose or both; in this situation, health-care providers should administer OPV only after discussing the risk for VAPP with parents or caregivers. Precautions and Contraindications OPV should not be administered if persons have experienced an anaphylactic reaction to a prior dose of OPV. Although vaccinations for pregnant women should be avoided, OPV can be administered (in accordance with the recommended schedules) if a pregnant woman requires immediate protection against polio. Persons who have immunodeficiency disorders (e.g., severe combined immunodeficiency syndrome, agammaglobulinemia, or hypogammaglobulinemia) are at a substantially greater risk for VAPP. Therefore, OPV should not be administered. If a household contact(s), of an immunodeficient person, inadvertently receives administration of OPV, the household contact(s) should avoid close contact with the immunodeficient person for approximately 4-6 weeks after vaccination. If this is not feasible, rigorous hygiene and hand washing after contact with feces and avoiding contact with saliva can be an acceptable alternative (although probably less effective). The following are not contraindications for vaccination: Breastfeeding A child who has mild diarrhea Minor upper respiratory illnesses with or without fever Mild to moderate local reactions to a previous dose of vaccine Current antimicrobial therapy The convalescent phase of an acute illness Additional information about the ACIP recommendations for polio can be found in the CDC. Morbidity and Mortality Weekly Report (MMWR) May 19, 2000/vol. 49/No. RR-5 at: ftp://ftp.cdc.gov/pub/Publications/mmwr/rr/rr4905.pdf. More information on the false contraindications for vaccination can be found in the CDC. Morbidity and Mortality Weekly Report (MMWR) January 28, 1994/vol. 43/No. RR-1:23-26 at: ftp://ftp.cdc.gov/pub/Publications/mmwr/rr/rr4301.pdf. Health information for travelers can be found at: www.cdc.gov/travel. Table of contents

Can I or my child get AIDS, or the HIV virus, or chronic fatigue syndrome from vaccines? No. There is no evidence that vaccine supplies today are contaminated or that they are capable of causing HIV, AIDS, chronic fatigue syndrome, or other health problems. Table of contents

Do vaccines cause fibromyalgia, rheumatoid arthritis, arthritis, or lupus? After decades of vaccine use in the U.S., current research shows no definitive evidence proving vaccines cause chronic illness. According to the Arthritis Foundation, there is no known link between vaccines and fibromyalgia, rheumatoid arthritis, or lupus, and while the number of persons with these conditions has been rising, the statistics do not support alarm over these increases.(1) In considering the increases, it's important to remember that rheumatoid arthritis (a type of arthritis that causes systemic inflammation, as well as joint problems), arthritis, and lupus are primarily diseases of middle and older age. A very large segment of the American population--the so-called "baby boomers"--are now entering the ages when these diseases occur, so an increase in the numbers of cases is to be expected. Perception of increases in fibromyalgia incidence may be because this disease has only recently been defined, and it is just in the past decade that physicians have known that the various symptoms of fibromyalgia (chronic muscle aches and pains, "trigger points" of pain, and chronic, sometimes overwhelming fatigue) do constitute a specific disease. Thus, it is not possible to know whether the number of cases detected these days represents an increase over that which occurred previously. Arthritis, on the other hand, is not a "new" disease. Evidence of osteoarthritis (arthritis confined to the joints, where one bone meets another) has been found as far back as the mummies of ancient Egypt. Its incidence increases with age. In a comprehensive 1994 study of adverse events associated with vaccination, the Institute of Medicine reviewed the possibility of a link between diphtheria and tetanus vaccines--these vaccines are generally given in combination--and arthritis. The Institute found that it is biologically possible for these immunizations to be associated with arthritis, primarily because the tetanus toxoid has the potential to induce serum sickness, which is a source of a temporary form of arthritis. However, the Institute also found that the evidence available in scientific studies up to 1994 was inadequate to determine whether this biologically possible link actually occurs. Since those findings were reported, one group of researchers found a link between rubella vaccine and temporary, acute arthritis, arthralgia (joint pain) or myalgia (muscle pain) when the vaccine was administered within 12 months of giving birth.(2) Another group found no evidence of any increased risk of developing chronic arthritis, arthralgia, or myalgia within the 12 months following vaccination; the women in this study were of childbearing age.(3) Similarly, the Institute found that a link between hepatitis B vaccine and acute or chronic arthropathy (inflamed, painful joints) also is biologically plausible, but the studies available are inadequate to accept or reject a causal link to vaccination. A link between the disease, hepatitis B, and arthropathy has been proven.(4) Table of contents

Who should not have vaccinations? Questions and concerns about the appropriateness of a vaccination for you or your child should always be discussed with your healthcare provider. He/She knows your medical history and can best recommend whether you or your child should receive a vaccine. According to the Vaccine Information Statements, the following applies: Diphtheria, Tetanus, and Pertussis Vaccines � Children should not get these vaccines or should wait if they have ever had a moderate or serious reaction after getting vaccinated; they have ever had a seizure; they have a parent, brother, or sister who has had a seizure; they have a brain problem that is getting worse, or they now have a moderate or severe illness. For more information on Diphtheria, Tetanus, and Pertussis Vaccines, visit the National Immunization Program web site at: http://www.cdc.gov/nip/publications/VIS/vis-dtp.pdf. Hepatitis A Vaccine � People should not get this vaccine if they have ever had a serious allergic reaction to a previous dose of hepatitis A vaccine. People who are moderately or severely ill should usually wait until they recover. For more information on Hepatitis A Vaccine, visit the National Immunization Program web site at: http://www.cdc.gov/nip/publications/VIS/vis-hep-a.pdf. Hepatitis B Vaccine � People should not get this vaccine if they have ever had a life-threatening allergic reaction to baker's yeast (the kind used for making bread) or to a previous dose of hepatitis B vaccine. People who are moderately or severely ill at the time the shot is scheduled should usually wait until they recover. For more information on Hepatitis B Vaccine, visit the National Immunization Program web site at: http://www.cdc.gov/nip/publications/VIS/vis-hep-b.pdf. Haemophilus Influenzae Type b (Hib) Vaccine � People should not get this vaccine if they have ever had a life-threatening allergic reaction to a previous dose of Hib vaccine. People who are moderately or severely ill at the time the shot is scheduled should usually wait until they recover. Children less than 6 weeks old should not get Hib vaccine. For more information on Haemophilus Influenza Type b (Hib) Vaccine, visit the National Immunization Program web site at: http://www.cdc.gov/nip/publications/VIS/vis-hib.pdf. Influenza Vaccine � People should talk with their doctor before getting this vaccine if they have ever had a serious allergic reaction to eggs or to a previous dose of influenza vaccine, or they have a history of Guillain-Barr� Syndrome (GBS). People who have a fever or are severely ill at the time the shot is scheduled should usually wait until they recover. For more information on Influenza Vaccine, visit the National Immunization Program web site at: http://www.cdc.gov/nip/publications/VIS/vis-flu.pdf. Lyme Disease Vaccine � People should not get this vaccine if they are less than 15 years of age; they are pregnant; they have arthritis caused by a previous case of Lyme disease, which has not responded to antibiotic treatment; or they have had an allergic reaction to a previous dose of Lyme Disease. People with immune system problems should check with their doctor before getting the vaccine. For more information on Lyme Disease Vaccine, visit the National Immunization Program web site at: http://www.cdc.gov/nip/publications/VIS/vis-lyme.pdf. Measles, Mumps, & Rubella (MMR) Vaccines � People should not get this vaccine if they have ever had a life-threatening allergic reaction to gelatin, the antibiotic neomycin, or a previous dose of MMR vaccine. If people are moderately or severely ill at the time the shot is scheduled, they should usually wait until recovery. Pregnant women should wait until after they have given birth to get the vaccine. The following people should check with their doctor: anyone who has HIV/AIDS, or another disease that affects the immune system; anyone being treated with drugs that affect the immune system (e.g. steroids) for 2 weeks or longer; anyone who has cancer; anyone taking cancer treatment with x-rays or drugs; anyone who has ever had a low platelet count (a blood disorder); or people who recently had a transfusion or were given other blood products. For more information on Measles, Mumps, & Rubella (MMR) Vaccines, visit the National Immunization Program web site at: http://www.cdc.gov/nip/publications/VIS/vis-mmr.pdf Pneumococcal Polysaccharide Vaccine � Healthy children who often get ear infections, sinus infections, or other upper respiratory diseases do not need to get this vaccine. Pregnant women should consult with their doctor before getting the vaccination. Women at high-risk of pneumococcal disease should be vaccinated before getting pregnant, if possible. PPV may be less effective in some people, especially those with lower resistance to infection. However, these people should still get the vaccine because they have a greater chance of becoming seriously ill from pneumococcal disease. For more information on Pneumococcal Polysaccharide Vaccine, visit the National Immunization Program web site at: http://www.cdc.gov/nip/publications/VIS/vis-ppv.pdf Pneumococcal Conjugate Vaccine � Children should not get this vaccine if they had a severe (life-threatening) allergic reaction to a previous dose of the vaccine. Children that are moderately or severely ill at the time the shot is scheduled should usually wait until they recover. Children with minor illnesses, such as a cold, may be vaccinated. For more information on Pneumococcal Conjugate Vaccine, visit the National Immunization Program web site at: http://www.cdc.gov/nip/publications/VIS/vis-pneumoConjugateInterim.pdf. Polio Vaccine � The following people should not get Inactive Poliovirus (IPV): anyone who has ever had a life-threatening allergic reaction to the antibiotics neomycin, streptomycin, or polymyxin B; or anyone who has a severe allergic reaction to a polio shot. Anyone who is moderately or severely ill at the time the shot is scheduled should wait until they recover. People with minor illnesses, such as cold, may, be vaccinated. Note: Oral Poliovirus (OPV) is no longer recommended. If you or your child will be getting OPV, ask for a copy of the OPV supplemental Vaccine Information Statement. For more information on Polio Vaccine, visit the National Immunization Program web site at: http://www.cdc.gov/nip/publications/VIS/vis-IPV.pdf. Chickenpox (Varicella)Vaccine � People should not get this vaccine if they have ever had a life-threatening allergic reaction to gelatin, the antibiotic neomycin, or (for those needing a second dose) a previous dose of chickenpox vaccine. Anyone who is moderately or severely ill at the time of the shot should usually wait until they recover. Pregnant women should wait to get the vaccine. (Women should not get pregnant for 1 month after getting the vaccine). The following people should check with their doctor about getting the vaccine: anyone who has HIV/AIDS, or another disease that affects the immune system; anyone being treated with drugs that affect the immune system (e.g. steroids) for 2 weeks or longer; anyone who has cancer; anyone taking cancer treatment with x-rays or drugs; or people who recently had a transfusion or were given other blood products. For more information on Chickenpox (Varicella) Vaccine, visit the National Immunization Program web site at: http://www.cdc.gov/nip/publications/VIS/vis-varicilla.pdf. Anthrax Vaccine � People should not get this vaccine if they have had a serious allergic reaction to a previous dose of the vaccine, or have recovered from cutaneous (skin) anthrax. Pregnant women should not be routinely vaccinated with anthrax. This is merely a precaution. Vaccination may be recommended for pregnant women that have been exposed, or are likely to be exposed, to anthrax. For more information on Anthrax Vaccine, visit the National Immunization Program web site at: http://www.cdc.gov/nip/publications/VIS/vis-anthrax.pdf. Table of contents

Do vaccines cause autism? To date, there is no scientific evidence to show that vaccines cause autism. The Institute of Medicine's Immunization Safety Review Committee recently examined studies about the health effects of the Measles-Mumps-Rubella (MMR) vaccine in young children and found that the evidence favored rejection of a causal relationship at the population level between MMR vaccine and autistic spectrum disorders (ASD).(5) Continued research is needed to examine the mechanisms of autism, along with the genetic, infectious, immunological, neurological, and environmental factors. Although a cure is not currently known for autism, autism is treatable with appropriate, individual intervention. For more information on autism and/or autism research, visit the following web sites: The National Center for Environmental Health at http://www.cdc.gov/ncbddd/dd/ddautism.htm, or http://www2.cdc.gov/nceh/contactnceh/frmSubmit.asp for public inquiries. National Institute of Child Health and Human Development (NICHD) Clearinghouse at 1-800-370-2943, or http://www.nichd.nih.gov/publications/pubs/autism1.htm. CDC, National Immunization Program at: http://www.cdc.gov/nip http://www.cdc.gov/nip/vacsafe/concerns/autism/. The Institute of Medicine. Immunization Safety Review: Measles-Mumps-Rubella Vaccine and Autism can be accessed at: http://www.iom.edu/iom/iomhome.nsf/WFiles/ISR-MMR-4Pager/$file/ISR-MMR-4Pager.pdf. Table of contents

Can I get animal diseases from vaccines that are made using animal cells? Vaccine Companies are required to test cell lines used for the presence of a variety of adventitious agents to prevent contamination of vaccines. Currently, there is no scientific evidence demonstrating the transmission of animal diseases to humans from vaccines. For more information about concerns of vaccine contamination, please visit the National Immunization Program web site at: http://www.cdc.gov/nip/vacsafe/concerns/gen/contamination.htm. Table of contents

Can't I just "wait and see" on my child's vaccinations? According to the recommended childhood immunization schedule, immunization should begin at birth and most vaccinations be completed by age 2. By immunizing on time (by age 2), you can protect your child and others from being infected with vaccine-preventable diseases. A decision to withhold vaccinations from your child puts your child, other children, adults, your community, and even your future grandchildren at risk of contracting vaccine-preventable diseases. (Children under 5 are especially susceptible to disease because their immune systems have not built up the defenses that are necessary to fight infection). An unvaccinated child will be at risk of becoming infected even when others are not yet ill, but are developing an infection. Any child with an infectious disease should be isolated at home to prevent the spread of disease to others. Keep in mind that many people may have a low resistance to disease (i.e., people who are being treated for cancer, people who have immune disorders, and elderly people). To protect these people, a parent of an unvaccinated child must take constant precautions. Unless you are exempt from vaccinations for religious or philosophical reasons (the laws vary among states), withholding your child's vaccinations can delay his/her entry into school until you comply with your state's school vaccination requirements. If you do qualify for an exemption from vaccination, you must take responsibility for the health of your own child and for the children and adults who come into contact with your child. For more information on why children should be immunized, see "If We Stop Vaccinating�": http://www.cdc.gov/od/nvpo/part6.htm and "What Would Happen If We Stopped Vaccinations?": http://www.cdc.gov/nip/publications/fs/gen/WhatIfStop.htm. For more information about immunization, see, "10 Things You Should Know About Immunizations": http://www.cdc.gov/nip/publications/fs/gen/shouldknow.htm. To view the Recommended Childhood Immunization Schedule United States, January-December 2001, go to: http://www.cdc.gov/nip/recs/child-schedule.PDF. Table of contents

Can epidemics occur today? In the United States? Yes. Vaccines have dramatically reduced the number of people that get infectious diseases. Without vaccines, epidemics of vaccine-preventable diseases can return. This would result in increased and unnecessary illness, disability, and death. For more information on why children should be immunized, see "If We Stop Vaccinating�": http://www.cdc.gov/od/nvpo/part6.htm and "What Would Happen If We Stopped Vaccinations?": http://www.cdc.gov/nip/publications/fs/gen/WhatIfStop.htm. Table of contents

Are we safe from epidemics? Because we have the technology and good fortune in this country to develop and distribute vaccines quickly and routinely, we are safe from many diseases. However, if we choose not to vaccinate, we place our community and ourselves at great risk of being infected with vaccine-preventable diseases. Such diseases can be brought into the community by an outside source (i.e., a traveler that is infected with the disease, or the bite of an insect that is carrying the disease); importation from another country; or because a pathogen (a virus or bacteria) has changed in a way that has either enabled it to avoid the immune system, or has made it stronger and more aggressive. When many people in a community or region become infected with the same disease, this causes an epidemic or disease outbreak. The decision to vaccinate is a decision to help protect our community and our self. When immunization programs achieve high levels of community immunity, the chance for a disease to be transmitted to a susceptible person is greatly reduced, thereby, reducing the possibility of an epidemic. For more information on epidemics, see "Disease Outbreaks: Past, Present and Future": http://www.cdc.gov/od/nvpo/intro8.htm. Table of contents

Why must my child have so many shots? Because the number of vaccines required to reduce disease has increased, the number of shots a child receives has also increased. However, no one wants to subject children to unnecessary discomfort. For this reason, vaccine researchers are working on alternative and less discomforting methods of administering vaccines, (e.g., by mouth or inhalation); combination vaccines are being used to help reduce the number of injections required; and pediatricians and vaccine experts are working together to develop new schedules that will reduce the number of injections needed at any one visit or altogether. For more information on combination vaccines, visit: http://www.cdc.gov/epo/mmwr/preview/mmwrhtml/rr4805a1.htm. Table of contents

Aren't there some chemicals and other substances added to vaccines? Yes. Chemicals are added to vaccines to inactivate a virus or bacteria and stabilize the vaccine, which helps to preserve the vaccine. Chemicals also prevent the vaccine from losing its potency over time. The amount of chemical additives in vaccines is very small and may not cause a serious allergic reaction. Common substances found in vaccines include: Antibiotics � prevents the growth of germs (bacteria) in vaccine cultures. Formaldehyde � inactivates bacterial products for toxoid vaccines and kills unwanted viruses and bacteria that might be found in vaccine-producing cultures. Thimerosal � a preservative used to prevent vaccines from spoiling. In 1999, the Federal Government asked vaccine manufacturers to eliminate or reduce the use of Thimerosal due to its mercury containment. All routinely recommended pediatric vaccines are now manufactured as either Thimerosal free or with only trace amounts (less than 0.5 micrograms per dose). Monosodium glutamate (MSG) and 2-phenoxy-ethanol � used to stabilize vaccines and help them remain unchanged even in the presence of forces such as: heat, light, acidity, humidity, etc. MSG is also found in many foods, (i.e. Asian foods and flavor enhancers). Aluminum � helps the vaccines stimulate production of antibodies to fight off diseases and aid other substances in their action. Egg protein � found in vaccines prepared using chick embryos. Ordinarily, persons who are able to eat egg products can safely receive these vaccines. For more information on vaccine additives, go to: http://www.cdc.gov/nip/vacsafe/concerns/gen/additives.htm. For more information on the update of Thimerosal, go to: http://www.cdc.gov/nip/vacsafe/concerns/thimerosal/index.html. Table of contents

I got a flu shot and I still came down with the flu. Why? The ability of the vaccine to protect against influenza during a particular season depends on several factors, but particularly 1) the match between influenza strains in the vaccine and strains circulating in the community, and 2) the ability of each person's immune system to mount a protective response as a result of the vaccination. There are several possible explanations for getting a flu-like illness after an immunization: It wasn't the flu. Instead, it was another virus, disease, or condition that caused flu-like symptoms (i.e., aches, pains, and fatigue). There are many viruses that can cause these symptoms: fibromyalgia, rheumatoid arthritis, and chronic fatigue syndrome. If this were the case, the influenza vaccine would not prevent the illness because the vaccine is only effective against illnesses caused by influenza viruses. Your immune system did not respond properly to the vaccination. You had already been exposed to the flu before you received the vaccine. Although the vaccine may not prevent everyone who takes it from getting sick, it does reduce the risk of severe illness, hospitalization, and death. That is why it is so important to get the vaccine each year for anyone who wants to reduce his or her risk of getting severely ill from influenza. For more information about the influenza vaccine, visit the following web sites: National Center for Infectious Diseases - http://www.cdc.gov/ncidod/diseases/flu/fluvac.htm. Influenza Information Statement - http://www.cdc.gov/nip/publications/VIS/vis-flu.pdf. Table of contents

If you didn't find the answer you need in this section... You Can: Visit the National Immunization Program at: http://www.cdc.gov/nip/; Visit the National Centers for Infectious Diseases at: http://www.cdc.gov/ncidod/; Visit the Center for Biologics Evaluation and Research at: http://www.fda.gov/cber ; Visit the National Institute of Allergy and Infectious Diseases at: http://www.niaid.nih.gov/index.html; Visit the National Institute of Child Health & Human Development at: http://www.nichd.nih.gov/index.html; Visit the Vaccine Injury Compensation Program at: http://bhpr.hrsa.gov/vicp/; Contact the National Immunization Information Hotline at 1-800-232-2522 (English); 1-800-232-0233 (Spanish), or Visit http://www.cdc.gov/od/nvpo/fs_tableVIII_doc2.htm for Federal Toll-Free Hotlines and Other Resources. Table of contents

Endnotes

1. Arthritis Foundation. Letter of May 15, 1997: "There is no evidence that defects in vaccine administered to newborns and children are contributing to a current explosion of chronic neurological and immune system dysfunction in the American population including lupus and rheumatoid arthritis. This certainly is not true in lupus, rheumatoid arthritis, or juvenile arthritis....Certainly the term explosion is not justified. The current scientific data reveals that the causes of lupus and rheumatoid arthritis are a combination of genetic susceptibility and then a variety of factors stimulating the immune process....I am not aware of any findings linking childhood immunizations with lupus or rheumatoid arthritis." 2. Tingle AJ, Mitchell LA, Grace M, et al. Randomized double-blind placebo-controlled study on adverse effects of rubella immunization in seronegative women. Lancet 1997;349:1277-1281. 3. Ray P, Black S, Shinefield H, et al. Risk of chronic arthropathy among women after rubella vaccination. Journal of the American Medical Association August 20, 1997;278(7):1-7. An abstract of this article is available at: http://jama.ama-assn.org/. 4. Institute of Medicine. Adverse events associated with childhood vaccines: evidence bearing on causality. Stratton KR, Howe CJ, Johnston RB Jr., editors. Washington, DC: National Academy Press, 1994:222-227. 5. Institute of Medicine. Immunization Safety Review. Measles-Mumps-Rubella Vaccine and Autism. Stratton K, Gable A, Shetty P, McCormick M, editors. Washington, DC: National Academy Press, 2001:1-9. The abstract of this article is available at: http://www.iom.edu/iom/iomhome.nsf/WFiles/ISR-MMR-4Pager/$file/ISR-MMR-4Pager.pdf.

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