Throughout my years as a pediatrician, I've seen lots of children suffer from serious diseases. The physical outcomes vary, but the suffering that sickness causes for children and their families is long remembered. It's heartbreaking to care for a sick child, especially when the disease could have been prevented.

That's why child immunizations are so important. I can't stress enough how safe, effective and crucial they are for young children. I know that many parents have concerns about vaccinating their children. Others simply forget or have a hard time keeping up with doctor's visits. It might seem like an inconvenient chore or that it can wait, but the diseases that vaccines protect against are real and highly contagious. Many are especially dangerous for infants and toddlers.

Unfortunately, the number of parents who immunize their children is dropping. Perhaps that's because some parents believe diseases like polio or rubella have disappeared. I've heard so many parents of sick children say, “;I didn't realize these diseases are still out there.”;

I can assure you that without vaccines for these infectious diseases, they could and would still plague our communities.

Take haemophilus influenzae type B (Hib), for example. This germ can cause the most terrifying and destructive diseases imaginable. It starts with mild, flulike symptoms but then attacks the brain or other critical organs rapidly, often causing brain damage or even death.

I'll ALWAYS remember the story I heard from a colleague. A 3-year-old boy came into the emergency room with a high fever and difficulty breathing. My colleague couldn't immediately diagnose him, but the child's windpipe was closing up quickly. Another doctor rushed in to assist. He took one look at the boy's chart and asked, “;Has this child been vaccinated against (Hib)?”; The answer was no, and a quick blood culture determined that it was in fact Hib. The boy required an emergency tracheotomy (an opening through his throat into his windpipe) and two weeks of intravenous antibiotics. He nearly died but, happily, survived.

Diseases like this are rare. But that's no consolation to a child with whooping cough gasping for air, or a baby with measles who has a terrible rash, high fever and violent cough. The reason that many infectious diseases are no longer common is, quite simply, because of vaccines.

In the case of the boy with the Hib infection, my colleague didn't immediately recognize the disease because he had never seen it. Since the Hib vaccine was created in the 1980s, Hib infections have decreased 99.9 percent, so some doctors have never treated it and hospitals could be unprepared for it. The quick thinking of the second doctor, who was older and had been practicing medicine before the vaccine was created, saved the boy's life.

While the boy was in intensive care, the hospital staff brought in teams of physicians so they could see the consequences that unvaccinated children could suffer.

But it's not just children. Adults who were never vaccinated, especially seniors or those with weak immune systems, can also contract infectious diseases from unvaccinated children. When you don't immunize your children, you're putting your friends, family and neighbors at risk, too.

HERE IS A list of the vaccinations and doses that children need by age 2:

» Diphtheria, tetanus and pertussis (DTap): Four doses. Diphtheria causes breathing problems and heart failure; tetanus (or lockjaw) causes painful muscle tightening; pertussis (whooping cough) causes long, violent coughing spells.

» Polio (IPV): Three doses. Polio is very contagious and can lead to muscle paralysis.

» Measles, mumps and rubella (MMR): One dose. Measles cause fever and rash and can lead to pneumonia; mumps cause fever and salivary gland swelling and can lead to meningitis and sterility; rubella in pregnancy can infect the unborn child, resulting in severe brain damage.

» Haemophilus influenzae type b (Hib): Four doses. Hib can lead to meningitis, pneumonia and other life-threatening infections.

» Hepatitis B (HepB): Three doses. Hepatitis B can cause liver damage, which can lead to liver failure or liver cancer.

» Varicella: One dose. Varicella zoster is a herpes virus that causes chickenpox, which can lead to pneumonia and reappear many years later as shingles.

» Hepatitis A (HepA): Two doses. Hepatitis A is a contagious liver disease that can cause jaundice, severe stomach pain and flulike symptoms.

» Influenza (TIV/LAIV): One dose. Influenza (the flu) is a highly contagious virus that's common in children. It causes fever, headache, coughing and sore throat, and can lead to pneumonia.

» Pneumococcal (PCV): Four doses. Pneumococcal disease can lead to meningitis, blood and ear infections, deafness, pneumonia and brain damage.

We owe it to our children to fight these dangerous diseases and help keep them out of our communities for generations to come. No vaccine is 100 percent effective, but their benefits are so important in helping to keep children healthy.

If you have questions about vaccines or the diseases they help protect against, talk to your doctor or visit HMSA's website at hmsa.com.