For many Georgia parents, the past few weeks have involved getting their 5-year-olds caught up on their shots. In every state, children must be up to date on their immunizations to attend school. But too often, children who are too young to attend school are overlooked. The result is an unvaccinated and undervaccinated population that presents a health care dilemma for the rest of the general public. Unimmunized children are not only a danger to themselves, but they also are a danger to other children — especially those who are too young to be fully immunized.

Nationally, only about 80 percent of children are up to date on their vaccinations at the age of 36 months. Not only are these children not up to date, but they also are very much behind. They should have completed their basic immunizations by the age of 18 months, long before age 4 or 5 when they should need only boosters before they start school.

In Georgia, the immunization rate of 73 percent is more problematic. Imagine if more than one out of every four children in the day care center is not properly vaccinated, possibly exposing all the other children to measles, polio or whooping cough.

Georgia’s immunization rate likely is tied to the fact that 11 percent of families are below the poverty level. Centers for Disease Control and Prevention data demonstrate that children living below the poverty level have lower immunization coverage rates — a fact associated with the need for low-income moms to find a way to get food on the table and the rent paid. Getting their kids immunized, which may require taking a day off from work, often takes a back seat.

On the other hand, there are parents who fail to immunize their children due to fear of side effects, religious beliefs or the mistaken belief that because nearly all the other children are immunized, theirs will never be exposed to diseases.

Unfortunately, “childhood diseases,” and other diseases that many think have been eradicated, are still around. Recent years have seen occasional outbreaks in the U.S. of measles, rubella (“German measles”) and polio. Whooping cough (pertussis) is still with us. Children still get pneumonia, and some get bacterial meningitis.

In July 2008, Georgia was one of 15 states to witness the largest outbreak of measles in the United States in more than 10 years, with 132 cases nationwide. Pertussis is also on the rise in Georgia, with 230 cases of pertussis in 2009, nearly double the year prior, and 225 cases in 2010. Sadly, one infant died during the 2009 outbreak. These are preventable tragedies because these are among the diseases against which childhood immunizations protect.

It is not only infants and preschoolers who need immunizations. Adolescents need a booster against some of those same childhood diseases, plus a meningitis shot. And the new human Papillomavirus vaccine is recommended for pre-adolescent and adolescent girls (although not required for school) to protect against cervical cancer.

Adults over age 65 should be immunized against pneumonia and shingles, and should get a flu shot every fall. In fact, everyone over 6 months of age should get an annual flu shot — but especially those who are elderly or who have a chronic disease such as diabetes or emphysema.

In the first part of the 20th century, infectious diseases were the leading causes of mortality, and children were at great risk of an early death from diseases such as measles and whooping cough. Thanks mainly to immunization and antibiotics, this is no longer the case.

But we have not conquered infectious disease. We keep it only at bay through immunization and other public health measures such as food inspection and health education.

So the beginning of school should be a reminder to everyone about immunization — not just for kindergartners, but for infants, toddlers, adolescents and adults as well.

Dr. Daniel Blumenthal is chairman of the Department of Community Health and Preventive Medicine at the Morehouse School of Medicine.