August is National Immunization Awareness Month, with the last week of the month emphasizing the need to vaccinate infants and children. The campaign to increase awareness is an opportunity to remind parents of the importance of childhood immunizations as they prepare for their children to enter daycare or school.

Parents are encouraged to obtain recommended immunizations for their children by age 2. With August being the final month before children return to school, it is a key time to remind parents to review the immunization status of all their children — including teens and college students.

Over the years, vaccines have prevented the spread of many serious life-threatening diseases and have contributed to the eradication of others.

In April, the Pan American Health Organization and the World Health Organization declared the Americas region to be free of rubella and congenital rubella syndrome. The United States was reported to be rubella-free in 2004, with no cases of rubella among residents of the United States.

The U.S. has also been polio-free since 1979, and the Americas region was declared free of polio in 1994. The last case of smallpox within the United States was in 1949, and the last reported case in the world was in Somalia in 1977.

Despite the efforts to immunize children for serious disease, each year there are cases of illness that could have been prevented by immunization.

The most recent example of disease spreading because of a lack of vaccines happened at the beginning of this year, when 125 cases of measles were reported in the United States between Dec. 28, 2014, and Feb. 8, 2015.

Of these, 110 were residents of California — with 49 patients having no history of vaccination, five having only one dose of measles vaccine, seven with two doses and one with three doses. Another 47 patients had an unknown status or undocumented vaccination status. Of those not vaccinated, 28 were intentionally unvaccinated. At least 17 of the patients had serious enough symptoms to require hospitalization.

An outbreak of mumps in Ohio in 2014 was reported to have identified more than 225 cases of the infection. That same year, the CDC reported 1,151 cases in the United States. In 2012, there were only 229 cases. Prior to the use of vaccinations in 1967, there were about 186,000 cases of mumps annually in the United States. Although most patients recover, mumps can lead to serious problems such as hearing loss or meningitis.

August is the month that many parents prepare for the start of school. Part of the preparation should be a review of their child's immunization records.