Although these words are often used interchangeably, they mean different things. Vaccinations describe the process of giving vaccines (in the forms of injections, oral drugs, or nasal sprays) to stimulate the production of antibodies to ward off certain diseases. Immunization is the term for making someone immune to a disease; vaccination is a form of active immunization. "When we vaccinate children, it stimulates their immune system to make antibodies that protect them against the bacteria or virus targeted by the vaccine," says Kristen Feemster, M.D., an infectious - disease specialist at The Children's Hospital of Philadelphia. You can also make someone immune by giving him pre-formed antibodies, which is called passive immunization.
Thanks to vaccines, many infectious diseases that once routinely killed or permanently injured Americans are at all-time lows. Unfortunately, the same can't be said for other countries where diseases like measles, diphtheria, and polio continue to claim thousands of lives every year. "International travel -- both to and from the U.S. -- increases everyone's exposure risk," says Anita Chandra-Puri, M.D., a spokesperson for the American Academy of Pediatrics and a pediatrician at Northwestern Memorial Physicians Group in Chicago.
There's no federal mandate; however, each state has its own law that requires children to have certain vaccinations before attending public school. Children whose immune systems are compromised because of organ transplants, cancer, HIV, or other illnesses are medically exempt from certain vaccinations. Some states allow parents to opt out of vaccinations for religious or philosophical reasons. You can find your state's vaccination requirements at CDC.gov/vaccines.
The U.S. has the safest, most effective vaccinations in the world, thanks to stringent testing requirements implemented by the Food and Drug Administration (FDA). Even after a vaccine is approved, the FDA still monitors it for problems. Like any medication, vaccines can cause side effects. Most are mild: soreness or swelling at the injection site, a slight rash, or a mild 24-hour fever. A small number of children experience chills, high fever, and muscle ache. Severe reactions, such as seizures and brain damage, are extremely rare.
Infants' immature immune systems make them especially vulnerable to deadly diseases, so vaccinating early is critical. Exposing babies to a handful of different immunologic components (parts of a bacteria or virus that stimulate an immune response) in the form of a vaccine is nothing compared to the thousands of germs they encounter every day. "An infant's immune system is revved up from the moment he leaves the sterile womb," Dr. Feemster says. In fact, research suggests that babies can theoretically make antibodies to 100,000 vaccines at one time.
No study has ever shown a connection between vaccines and autism. In 1998, the medical journal The Lancet published a study by British researcher Andrew Wakefield, M.D., conducted on eight children with autism. The study suggested a link between the measles-mumps-rubella (MMR) vaccine, intestinal problems, and, consequently, autism. The study was retracted in 2010 after studies conducted on hundreds of thousands of children failed to replicate his findings. In fact, these studies showed both vaccinated and unvaccinated children were equally at risk for autism. What's more, Dr. Wakefield lost his medical license after it was determined that he acted unethically when selecting study participants, used seriously flawed lab techniques, and fraudulently omitted key facts from his findings. In addition, studies have found no link between autism and thimerosal, a mercury-based preservative once used in vaccines. All vaccines marketed in the U.S. and recommended for children 6 years or younger contain no thimerosal or only trace amounts (1 microgram or less per dose), with the exception of inactivated influenza vaccine. Concerned parents can ask for thimerosal-free flu shots or the nasal spray, which is available to kids age 2 and older.
Any disease can make a comeback if people stop getting vaccinated. There were more than 27,000 incidents of whooping cough (pertussis) in the U.S. in 2010. Studies show that children who skip the pertussis vaccine are 23 times more likely to get sick with the disease than those who are vaccinated, and outbreaks are especially common in schools and day cares. Measles is another reemerging disease. More than 200 unvaccinated American children and adults became ill with measles in 2011 after being exposed to it by infected international travelers. Some parents who forego the varicella vaccine also expose their children to chickenpox, which causes itchy blisters (pox), fever, and fatigue. It also can lead to severe skin infection, scars, pneumonia, brain damage, and death.
Every year, Centers for Disease Control and Prevention (CDC) releases updated vaccination recommendations for infants, children, teens, and adults. Here's a look at who needs to get what and when, as of February 2012.
Vaccinations are not always available in other parts of the world. As a result, life-threatening diseases are still widespread, especially in developing countries. Depending on your destination, your child may need these additional vaccinations:
Meningococcal (MCV4): For children age 2 and older traveling to sub-Saharan Africa, Saudi Arabia, or countries where meningitis is common.
Yellow Fever: For children 9 months and older traveling to Africa, South America, or other countries where yellow fever is common.
Typhoid: For children age 2 and older traveling to Africa, Asia, Latin America, or other countries where typhoid is common.
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