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FDA has licensed four Hib vaccines, including a combination of other vaccines mentioned earlier. The most recently approved vaccine is distributed in the United States under two brand names, OmniHib and ActHIB.

Depending on the brand of vaccine, Hib is given in either three or four doses by the time the child is 12 to 18 months old. Side effects are very minor, consisting mostly of low-grade fever and soreness at the site of the shot.

DTP

The DTP shot is a combination inoculation against diphtheria, tetanus and pertussis. It is given at 2, 4, 6, and 15 to 18 months of age, with a booster between 4 and 6 years.

Diphtheria is an infection of the throat, mouth and nose. It's extremely rare today, but highly contagious. The infection causes a sore throat and cough. Sometimes a fine web of gray membrane forms over the tonsils, blocking the windpipe and suffocating the child. If not promptly treated, diphtheria can also lead to pneumonia, heart failure, and paralysis.

Pertussis, or whooping cough, is life-threatening, especially in children under 1 year. It's caused by a bacterium that clogs the airways with mucus, causing a severe cough that sounds like a "whoop." The coughing can last two months, inviting other infections such as pneumonia or bronchitis.

The pertussis component of DTP causes more adverse reactions than any other vaccine. Most common are fever, soreness at the site of the shot, and irritability. In rare cases, the vaccine causes very high fever and convulsions.

FDA licensed in 1992 a version of the pertussis vaccine with potential for fewer local and febrile reactions. Unlike the old version, which is made from whole cells of pertussis bacteria that have been killed, the new vaccine is "acellular," made from portions of the cells. It has fewer side effects and has been approved for the fourth dose, given between 15 and 18 months, and the last dose, given before school entry. Several acellular pertussis vaccines are now licensed for infants.

Tetanus is a rare infection caused by bacteria found in dirt, gravel and rusty metal. It enters the body through a cut, creating a toxin, or poison, that causes the muscles to spasm. The toxin attacks jaw muscles first, often resulting in lockjaw. Tetanus can also cause the breathing muscles to spasm, resulting in death for 3 out of 10 people who get it.

The primary series of tetanus shots is given as part of the DTP shot during infancy. After that, the tetanus vaccine should be given as a booster every 10 years throughout life.

Hepatitis B

Hepatitis B is a viral disease transmitted through blood and body fluids. In its acute phase it can cause liver failure and death. It can also become chronic, causing liver damage, including cancer, over a number of years.

Except for infants born to mothers with this infection, children are not at great risk of developing hepatitis B, but health-care workers, homosexuals, and intravenous drug users are. Attempts to vaccinate adults have been largely unsuccessful, however. It's easier to reach children because school enrollment requires immunization.

Therefore, for lifelong protection, CDC has recommended that all infants be vaccinated before 15 months of age in three doses. There are no serious reactions to the vaccine.

Polio

Polio is remembered by many older Americans as a frightening disease that was epidemic during the 1950s. In 1952, more than 20,000 people — mostly children — were afflicted, according to CDC. Polio's first symptoms are fever, sore throat, headache, and stiff neck. The potentially fatal disease can soon progress to paralysis of the lower limbs and chest, making walking and breathing difficult or impossible. There is no cure for the disease.

There are two polio vaccines. One is an inactivated polio vaccine (IPV) in which the polio virus has been killed. Licensed in 1955, this vaccine is injected into the patient. The second vaccine is made from live attenuated (weakened) polio viruses. This oral polio vaccine (OPV) was licensed in 1963 and is taken as drops in the mouth.

Since the development of the oral vaccine, the incidence of polio has dropped to fewer than 10 cases per year. In fact, the oral vaccine has entirely prevented polio caused by the wild virus (not vaccine related) in North and South America since 1991, according to the Pan-American Health Organization.

However, the oral vaccine itself does cause paralytic polio in a very few children who received the vaccine, and in a few adults who came in close contact with recently vaccinated children. The risk of contracting polio this way is no more than 1 in 1.5 million. It is greatest for people who have immune deficiencies such as AIDS, cancer, or other diseases that make it hard for the body to fight infection. Because of this risk, CDC recommends that IPV be given for doses one and two to all children. Those who have immune deficiencies or who live with adults who do should only be given IPV. Parents who have not been vaccinated for polio should consider getting vaccinated with IPV before the child receives the oral vaccine.

Tags: Childhood Immunizations

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FDA is A United States government body that oversees medical devices, including contact lenses, intraocular lenses, excimer lasers and eyedrops. In the US, these products must be approved by the FDA before they can be marketed.