QUESTION:
If the hepatitis A virus is most commonly transmitted through contact with the stool of infected people, why should people who are careful to be clean need to be vaccinated?

ANSWER:
Cleanliness - such as hand washing after using the bathroom or changing diapers - is an excellent preventive measure, although it is not 100% effective. People infected with the hepatitis A virus often transmit the illness to others 1-2 weeks before they even begin to feel sick. And children often do not show any symptoms of illness at all, so they can unknowingly spread the virus. About one-third of the cases in the U.S. occur in children younger than 15 years of age. In addition, hepatitis A can be spread through contaminated food and water. Routine hepatitis A vaccination for children is only recommended for those living in areas with high rates of hepatitis A. Call your local health department or health care provider to find out whether hepatitis A vaccine is recommended for your child.

QUESTION:
I know that most people who get hepatitis B are adults. Why is it recommended that the hepatitis B vaccine series be given to infants?

ANSWER:
National immunization recommendations call for the routine immunization of all infants against hepatitis B because:

In addition:

• The earlier in life a child is exposed to the disease, the more likely he/she will become a chronic (lifelong) carrier. Adding hepatitis B to the already established immunization schedule helps us reach more people before they become chronic carriers.
  
• Hepatitis B virus infects 200,000 Americans annually; thousands of the victims are adolescents and young adults. About 10,000 people each year suffer sever liver damage (cirrhosis) or liver cancer caused by hepatitis B virus. In the US, more than 1.25 million people are chronically infected and at least one-third of those were infected as infants or children.
• There is no specific treatment for acute hepatitis B. The virus can cause liver damage, liver cancer and death.
• Unfortunately, vaccinating just high-risk individuals against hepatitis B has not proven to be an effective method for decreasing the incidence of this disease.

QUESTION:
Does hepatitis B vaccine cause multiple sclerosis (MS) or SIDS (Sudden Infant Death Syndrome)?

ANSWER:
No.

Multiple sclerosis (MS): Analyses by the World Health Organization, U.S. Institute of Medicine and the Medical Advisory Board of the National Multiple Sclerosis Society conclude that there is no evidence that the hepatitis B vaccine causes MS or other neurological diseases.

MS is an autoimmune disorder in which a person's antibodies attack the body's own myelin (a sheath that covers the nerves). MS is a lifelong illness which fluctuates through periods of exacerbation (symptoms worsen) and remission (symptoms subside). The cause of MS is unknown, but the most widely held belief among medical experts is that patients are genetically at risk for the disease and some environmental factors can "trigger" disease exacerbation.

There is no evidence that hepatitis B vaccine increases the rate of MS in otherwise healthy individuals. A study by the French National Drug Surveillance Committee revealed that recipients of over 60 million doses of hepatitis B vaccine given between 1989-1997 were less likely to have neurological disease, including MS, than the general population. Hundreds of millions of persons worldwide have been immunized with the hepatitis B vaccine without developing MS or any other autoimmune disease. The National Multiple Sclerosis Society supports the wide and general use of hepatitis B vaccine.

In May 2002, the Safety Review Committee of the IOM published a report of their findings regarding the possible association between hepatitis B vaccine and multiple sclerosis and related disorders. Following a thorough analysis of the studies of hepatitis B vaccine-exposed populations compared to unvaccinated patients with MS, the Committee concluded that the evidence did not support a causal relationship between hepatitis B vaccine and multiple sclerosis. For a copy of the full IOM report, visit www.cdc.gov/nip/news/iom-hepb-5-2002/iom.htm

Sudden Infant Death Syndrome (SIDS): Since 1991, infants have been receiving hepatitis B vaccine starting as early as the first day of life. If SIDS were somehow related to hepatitis B vaccination, we would expect to see an increase in SIDS deaths since 1991. However, this is not the case. In fact, there has been a steady decrease in the numbers of newborn deaths as the number of hepatitis B vaccinations have increased (see graph below).

Almost all infants are vaccinated during the first year of life. Because vaccines are usually given at ages 2, 4, and 6 months, there is a measurable chance of any event or death occurring within 24 hours of vaccination by coincidence alone. It is similar to saying that eating bread causes car crashes, because most car drivers who are in accidents could probably be shown to have eaten bread within the past 24 hours.

The Institute of Medicine reports: "All controlled studies that have compared immunized versus non-immunized children have found either no association...or a decreased risk...of SIDS among immunized children."

DTaP vaccine protects against diphtheria, tetanus and pertussis (whooping cough). Of these diseases, pertussis (also known as the "100-day cough") currently poses the most serious threat to infants and children in the United States. Complications of pertussis in infants include pneumonia, convulsions, and in some cases brain damage or death.

Since 1995, there has been a sustained increase in the number of pertussis cases in Washington State. In 1999 and 2000, there were 739 and 458 confirmed cases reported statewide. There have been 4 pertussis-related deaths reported since 1996, and all four were infants.

Recent update (2004) on pertussis:

Pertussis continues to increase, with over 800 cases reported in Washington State and 280 cases reported in King County in 2003. In King County in 2003, 53% (20/38) of the infant cases reported required hospitalization. Infants with pertussis might not be able to cough--instead, they may have problems feeding and may stop breathing at times. Until babies receive the first dose of DTaP vaccine at two months of age, they have no protection against pertussis, and they become better protected against severe pertussis with each dose of DTaP vaccine they receive. To help protect infants from pertussis and other infections, keep them away from persons with colds and respiratory illnesses. For more information on pertussis in King County and the impact on infants, go to www.metrokc.gov/health/epilog/vol4401.htm#pertussis

Nationally, a total of 17 pertussis-related deaths were reported to the CDC in 2000. All of the deaths occurred among infants whose symptoms began before they were four months of age.

Of additional concern is the major epidemic of diphtheria that has been in progress in the former Soviet Union since 1990. The decline in the former Soviet Union's diphtheria vaccination rates has resulted in an increase from 839 cases in 1989 to nearly 50,000 cases and 1,500 deaths from diphtheria in 1995, the last year for which we have confirmed statistics. This poses a serious concern of importing cases of diphtheria into the United States.

QUESTION:
What is the difference between the old "whole-cell" DTP vaccine and the new acellular DTaP vaccine?

ANSWER:
The new vaccines for pertussis, available since 1997, are known as "acellular" vaccines. They contain only the specific parts of the pertussis bacteria thought to be important for immunity. These differ from the old "whole-cell" vaccines that contain whole, killed pertussis organisms. Although effective, "whole-cell" vaccines were associated with a higher frequency of local reactions (e.g. redness, swelling, pain at the injection site) and fever. Doctors and nurses in the U.S. now use only acellular pertussis vaccine.

QUESTION:
What are the side effects of the DTaP vaccine?

ANSWER:
Most children who receive the DTaP vaccine will have no adverse reactions or experience only minor discomfort. This is a major advantage over the previously used whole cell DTP vaccine, which was associated with a higher frequency of adverse reactions. The most common reactions are soreness, swelling, and redness at the injection site. These reactions are more common following the fourth and fifth doses of the vaccine. Usually these reactions last from one to two days. Serious reactions are reported rarely with the acellular pertussis vaccine.

QUESTION:
How effective is the DTaP vaccine and is it worth getting?

ANSWER:
A full series of shots protects approximately 80 children out of 100 from getting severe pertussis (similar to the old whole cell DTP vaccine). Approximately 95 out of 100 children will be protected from diphtheria, and virtually 100% of children will be protected from tetanus after the full DTaP series is given.

Children vaccinated with DTaP who do become ill with pertussis almost always have a milder illness than if they had not been vaccinated. A full primary series of four DTaP shots by age 18 months is recommended, with a booster dose given between 4-6 years of age.

• Because it is so contagious, the possibility of a child getting severe pertussis when exposed is far greater than the chances of experiencing a severe adverse reaction from the vaccine.
• Children, especially young infants, who catch pertussis are often critically ill.
• Insufficiently immunized children contribute to higher rates of pertussis disease in some communities.
• Most individuals who have had a full series of DTaP or DTP vaccine are protected from diphtheria, tetanus and severe pertussis for many years.

QUESTION:
Is there any evidence to indicate an association between the MMR vaccine and autism?

A summary of the evidence is available online at www.immunize.org/mmrautism

ANSWER:
No. In fact, the best available science indicates that the development of autism is completely unrelated to use of the MMR or any other vaccine. Experts in behavioral and developmental disorders agree that autism is most likely a genetic disorder that occurs before birth, although research continues on its exact cause. A working group organized by the National Institutes of Health in 1995 reached a consensus that autism is a genetic condition.

Typically, symptoms of autism first appear in children from 18-30 months of age. MMR vaccine is usually given to children 12 to 15 months of age. Although autism may be detected during the weeks or months following MMR vaccination, this does not necessarily mean that the disorder was caused by the vaccine.

One small review of 12 children conducted in England in 1998 by Wakefield and colleagues seemed to suggest such a link but has since been disproven by many other, larger studies:

• 2004: The Institute of Medicine's (IOM) Immunization Safety Review Committee concluded that: 1) there is no association between MMR vaccine and autism, and 2) there is no evidence for the hypothesis regarding a link between MMR and autism.
  
  
• 2004: Ten of the thirteen authors of the Wakefield study (1998) retracted the paper's interpretation, stating now that there was not enough data to establish a link between MMR vaccine and autism (Murch et al.).
  
  
• 2004: A study conducted by the CDC found that there was no difference in the age that children with autism and children without received their first dose of MMR vaccine (DeStefano et al.).
  
  
• 2002: A study of nearly 500,000 children in Denmark found that: 1) children vaccinated with MMR vaccine were not more likely to have autism than children who were unvaccinated, and 2) there was no association between the age at time of vaccination, the amount of time that had passed since vaccination, or the date of vaccination and the development of autism. This study provides strong evidence against the hypothesis that MMR vaccination causes autism (Madsen et al.).
  
  
• 2002: Bazian, an independent medical research group, conducted the most comprehensive and in-depth analysis of over 2,000 scientific studies spanning over 50 years of research on the possible association between MMR and autism. Only the highest quality studies that met specific standards were selected and analyzed. The study concluded, definitively, that there is no evidence of a connection between MMR and autism or inflammatory bowel disease (Donald, A. et al.).
  
  The researchers also considered the study by Wakefield and colleagues, which initially raised the question of a possible association between MMR and autism. They found several flaws in the Wakefield study: 1) there were only 12 children involved in the study; generalizations about the causes of autism cannot be made with such a small number of cases; 2) parents were surveyed up to 8 years after their child was vaccinated, and 3) it lacked a control group. A control group is an essential element of the scientific process. Because Wakefield's study did not compare children who were vaccinated with MMR with those who were not vaccinated, it is impossible to reach the determination that MMR caused autism.
  
  
• 2001: The IOM Immunization Safety Review Committee concluded that the evidence does not support a link between MMR and autism at the population level. Other leading medical groups, such as the American Academy of Pediatrics and the World Health Organization and British Health Authorities, have reached similar conclusions.
  
  
• 2001: A study in California demonstrated that although a dramatic increase in the number of cases of autism was reported between 1980-1994, the percentage of children who received the MMR vaccine remained the same (Dales, L. et al.).
  
  
• 1999: Researchers in the United Kingdom (Brent Taylor, et al.) studied the records of 498 children with autism born between 1979-98. They found that the percentage of children with autism who received the MMR vaccine was the same as the percentage of children who were not autistic who received the vaccine. They also found no difference in the age of diagnosis of autism in vaccinated and unvaccinated children.
  
  To watch an excerpt of a film ("Fragile Lives-Immunization at Risk") on the increased incidence of measles in Ireland and the serious impact among children, following a dramatic decrease in measles vaccination rates among children, go to www.childrensvaccine.org, then select Part 4 - "Rejection -Measles in Ireland"

QUESTION:
Is it safer to give the combined MMR vaccine as three separate shots?

ANSWER:
No. Giving the MMR as three separate vaccinations at three different times would leave children unnecessarily exposed to the serious diseases the MMR vaccine prevents measles, mumps and rubella. Delaying vaccination could also lead to an increase in the number of measles, mumps and rubella cases and related complications, such as pneumonia and brain damage.

According to the CDC, if rubella vaccine were delayed, 4 million children would be susceptible to rubella for 6 to 12 months. This could allow preventable cases of congenital rubella syndrome (CRS) to occur when infected children transmit the disease to pregnant women. One of the few known causes of autism is CRS. Thus, if rubella infection can be prevented in pregnant women, there is a greater chance of preventing autism.

QUESTION:
Is it still worth being immunized against polio?

ANSWER:
Yes! Although wild polio disease has been eliminated from the United States since 1979, it still exists in other countries. Efforts are underway to eliminate polio worldwide. However, as long as polio exists in the world, our children need protection. Diseases which are largely under control in the United States are only a plane ride away.

QUESTION:
Are there two different types of polio vaccines?

ANSWER:
Yes. They are live, oral polio vaccine (OPV) and inactivated polio vaccine (IPV) which is injected. OPV was the vaccine of choice for routine immunization of most children in the United States from 1963 to the mid-1990s. However, as of January 2000, an all-IPV schedule was recommended for children in the U.S. OPV is no longer available in the U.S.

QUESTION:
Why isn't OPV used in the United States any longer?

ANSWER:
OPV has been associated with a very rare occurrence of paralysis in people who receive the vaccine and in those with whom they have had contact. Approximately eight cases of vaccine-associated paralytic polio (VAPP) occurred in the U.S. each year when OPV was the primary vaccine in use. This represented about one case per 2.5 million doses administered. The last case of VAPP was reported in 1999.

Because wild polio virus has been eliminated from the U.S. and other countries in the Western Hemisphere, an all-IPV schedule is now recommended. IPV cannot cause polio because it does not contain live polio virus.

QUESTION:
Chickenpox (varicella) isn't a very serious disease. Why vaccinate?

ANSWER:
Complications from varicella disease, such as pneumonia and encephalitis, "flesh-eating" bacterial infection and death can and do occur in children and adults. Before chickenpox vaccine became available in 1995 in the U.S., 7,200 children were hospitalized and 50 children died each year. Most of the hospitalizations and deaths occurred in previously healthy children.

Vaccinating against the illness during childhood will help reduce the incidence of the disease (and related complications) in later years. Varicella vaccine also reduces the risk of "shingles", a painful nerve and skin disease caused by reactivation of the varicella virus later in life.

QUESTION:
Does immunity from the varicella vaccine last?

ANSWER:
Available data indicate that protection from varicella vaccine should last for at least 20 years. Experience with other live viral vaccines (like measles, mumps and rubella vaccine) has shown that postvaccination immunity remains high throughout life. Studies are ongoing to determine how long protection from varicella vaccine lasts and whether booster doses may be needed in the future. Even if an immunized individual develops chickenpox after being exposed to the disease, the illness will be much milder than if the person had never been vaccinated.

QUESTION:
What is pneumococcus? Is there a pneumococcal vaccine for children?

ANSWER:
Pneumococcus is a bacteria that is the most common cause of pneumonia, meningitis, sepsis (bloodstream infection causing shock), sinusitis, and ear infection in children under two years of age.

The pneumococcal polysaccharide vaccine, which has been used in the United States since 1983, is not recommended for children under two years of age because it is ineffective in this age group.

A new pneumococcal conjugate vaccine that can be used in children under two years of age became available in 2000. This vaccine targets the 7 most common types of pneumococcus that cause the majority of invasive disease in this age group. In the past, pneumococcal infections could be treated effectively with certain antibiotics. However, many of these infections are becoming resistant to antibiotics. Preventing pneumococcal infection through vaccination is even more important for this reason.

QUESTION:
I heard that the recommendations for flu vaccine have changed and that I should have my 7-month old baby vaccinated. Is this true? I thought flu vaccine was only recommended for the elderly.

ANSWER:
Yes. In the past, the ACIP encouraged infants 6-23 months of age to get flu vaccine because infants in this age group with influenza are more likely to have serious illness and complications, including hospitalization. Starting in 2004, infants 6-23 months of age are recommended to get flu vaccine. Additionally, household contacts and caretakers of infants under two years of age are recommended to get flu vaccine each year, to protect infants and children they have close contact with. Children under 9 years of age getting flu vaccine for the first time should get 2 doses, 4 weeks apart. The best time to get flu vaccine is in October or November.

An annual flu shot is also recommended for the following groups, according to the CDC:

• Women who will be past their 3rd month of pregnancy during flu season (November through April);
• Everyone 50 years of age or older;
• Anyone whose immune system is weakened because of cancer treatment or HIV/AIDS;
• Anyone (including family members and children) living with or coming in close contact with people who have serious chronic health conditions;
• Anyone who wants to reduce their chance of catching the flu.

QUESTION:
I heard that there is a new flu vaccine that is given in the nose. Can my 7-month old get this new type of flu vaccine?

ANSWER:
There is a new type of flu vaccine that can be given in the nose (intranasal). FluMist^TM is a live-attenuated (weakened) vaccine that was licensed in 2003 and is sprayed into both nostrils. Inactivated influenza vaccine ("flu shot") is the flu vaccine that has been used for many years. However, your 7-month old cannot get FluMist^TM because it is only approved for use in healthy children and adults who are 5 to 49 years of age.

FluMist^TM should not be given to the following people:

• People under 5 years of age and 50 years of age or older;
• Pregnant women;
• People with some chronic health conditions like heart and lung disease;
• People with weakened immune systems, due to diseases like HIV/AIDS or medications like anti-cancer drugs; or
• Children and adolescents on long-term aspirin treatment.