Purchasing new clothes, shoes, a backpack and lunchbox will be on many parents' to-do lists as they prepare to send their children back to school in the coming weeks. But what about making sure their children are current with their immunizations?

All states have immunization requirements for children entering day care or school. The American Academy of Pediatrics recommends that children in the United States receive vaccinations for hepatitis A, hepatitis B, diphtheria, tetanus (lockjaw), pertussis (whooping cough), haemophilus influenzae type b, pneumococcal disease, polio, rotavirus, influenza, measles, mumps, rubella (German measles), varicella (chickenpox) and meningococcal disease. The academy also suggests that girls at least 9 years old receive the human papillomavirus vaccine (HPV).

"Immunization is one of the most effective ways to prevent disease. Vaccine-preventable disease levels have been reduced by more than 99 percent since the introduction of the immunizations," said Gerald Fendrick, M.D., Chief of Pediatrics at Our Lady of Lourdes Medical Center.

For example, the haemophilus influenzae type b vaccine protects against an infection that can seriously harm a child's brain, blood, bones, throat and area surrounding the heart. The hepatitis A shot protects against a virus that causes fever, nausea, vomiting and jaundice, while the hepatitis B vacccine protects against the virus that can cause lifelong liver problems. The diphtheria vaccine protects against an infection of the throat that can block the airway and cause serious breathing difficulty.

Dr. Fendrick emphasized that children be immunized against whopping cough, or pertussis, a respiratory illness with cold symptoms that progress to severe coughing, as incidences of the disease have increased in recent years. The vaccine is given in the same shot as diphtheria and tetanus to children at ages 2 months, 4 months, 6 months, 15 to 18 months, 4 to 6 years and 11 to 12 years.

In addition, the guidelines for administering the varicella, or chickenpox, vaccine have changed, Dr. Fendrick said. Children now should get the first dose at 12 to 15 months, with a second shot at 4 to 6 years, he said.

Some parents may hesitate to have their children vaccinated for fear their children will have serious side effects or may even get the illness the vaccine is supposed to prevent. Because the components of vaccines are weakened or killed -- and in some cases, only parts of the microorganism are used -- they're not likely to cause any serious illness, Dr. Fendrick said.

"Vaccines are safe. Side effects are usually mild and last only a short time. Some children have no side effects at all," he said. "None of the possible side effects should keep your child from getting shots unless your physician says so."

Dr. Fendrick encourages parents to discuss with their child's physician any worries they may have, as well as if anyone in the immediate family had a bad reaction to a vaccine. The doctor also can recommend ways to control reactions, such as giving acetaminophen before or after the shot.

Some parents also have raised concerns that the measles, mumps, rubella (MMR) vaccine, either by itself or combined with other vaccines containing a preservative called thimerosal, could cause autism. Large scientific studies have found no link between autism and the vaccines and thimerosal is no longer found in routine childhood vaccinations.

Your pediatrician or family physician will determine the best vaccinations and a schedule that makes sure your child gets the right shots at the right time, Dr. Fendrick said.