An Update on Immunizations

One of the most important things a parent can do for their child is to guarantee his or her immunizations are up to date. Immunizations are one of the most effective methods of preventing disease, disability and death. Also immunizations have been protecting children from serious diseases for over 50 years. Some people believe vaccines are not necessary anymore because the diseases we are vaccinating against are rare in the U.S., however, the viruses and bacteria which cause these diseases still exist and can be passed on to non-vaccinated individuals. Many of these diseases are still very common in developing countries, a good example of this is measles. In the U.S. where we regularly vaccinate against measles, there has been a greater that 99% reduction in occurrences of measles. However, more than 90% of individuals who are not vaccinated get the measles when exposed to the virus. Up to 20% of the patients with the measles require hospitalization, 7-9 % suffer complications such as pneumonia, diarrhea and ear infections and, though less common, some individuals with measles develop encephalitis resulting in brain damage and one of every 1,000 persons who contract measles will die.¹

As a whole, in the U.S. we do a very good job with immunizations. Many states (including Colorado) have special programs to assure children receive the appropriate shots. As of 1997, approximately 90% of children age 19-35 months had received the recommended doses of DTP, Polio, Hib and measles vaccines.²  However in Colorado, more than 12,000 school children were not immunized last year and the number has been growing in recent years. Vaccines, which usually are given as shots, protect a child by causing the child's body to produce antibodies against a specific virus or bacteria. The antibodies produced make the child immune when exposed to the disease. Most immunizations are given in the first two years of life. Some additional shots are necessary before beginning school and some booster shots are necessary in older children/teenagers.

The standard recommended immunizations for children are as follows (see Figure 1):

DTaP

This protects against diphtheria (a potentially fatal throat infection), tetanus (lockjaw), and pertussis (whooping cough). This vaccine should be given at 2 mos, 4mos, 6mos, 15-18mos, 4-6yrs and a Td (tetanus) between 11-16yrs. (Total 5 shot by school age). Tetanus boosters should be given every 10 years even in adulthood.

IPV

This vaccine protects against polio, which can cause paralysis or death. Though two forms of polio vaccine exist (oral and injectable) current recommendations are that all doses be given by injection. This vaccine is given at 2 mos, 4mos, 6-18 mos and at 4-6 yrs (Total- 4 shots).

Hepatitis B

This vaccine protects against a virus that can cause serious liver disease. Children need to receive 3 shots usually at birth-2mos, 1-4 mos and 6-18 months.

MMR

This vaccine protects against measles, mumps and rubella (German measles). This vaccine should be given at 12-15 mos of age and at 4-6 years of age (Total- 2 shots).

Varicella

This is a fairly new vaccine which protects against chicken pox which in addition to the common rash can cause serious complications such as bacterial skin infections, pneumonia and infections of the brain. Each year around 9,000 people are hospitalized with chicken pox and around 100 people die as a result of this virus.⁷  This vaccine is given between 12-18 mos in a single dose. (Total- 1 shot)

Hepatitis A

This vaccine protects against a virus that can be spread from person to person or through contaminated food or water and can cause severe liver disease. This vaccine is only recommended in selected regions and for high-risk groups.

Prevnar

This vaccine is the newest agent available to help protect children against serious childhood diseases. It protects against a bacterium called Streptococcus Pneumoniae that will be discussed in further detail below. The recommended administration is at 2 mos, 4 mos, 6 mos, and 12-15 mos. (Total: 4 shots). If an infant begins the series between 7-11 mos of age, 3 doses are recommended. Between 12 mos -23 mos two doses are recommended and between 2 - 9 years a single dose may be given.³

Prevnar, a multivalent conjugate pneumococcal vaccine, received FDA approval in February 2000 and was added to the American Academy of Pediatrics immunization recommendations in August 2000. Prevnar is a vaccine against Streptococcus pneumoniae (Strep. pneumo.) which is the most common cause of invasive bacterial infections in children. In the United States each year there are an estimated 16,000 cases of pneumococcal bacteremia (bacteria infection in the blood stream) and 1,400 cases of pneumococcal meningitis (infection in the spinal fluid) and 71,000 cases of pneumonia in children under age 5.⁵  Children under age 2 are at the highest risk for severe infection secondary to these bacteria. Of the children who develop meningitis, up to 50% will have brain damage and hearing loss and around 10 % will die. In addition to these very devastating pneumococcal infections, Strep. pneumo. is also responsible for 5-7 million cases of otitis media (ear infections) annually, making Strep. pneumo. the most common bacterial cause of acute otitis media, sinusitis and "strep throat". The risk of pneumococcal infections is 2-3 fold higher in children who attend daycare and in immunocompromised children (when the immune system doesn't work correctly). The good news is that the Prevnar vaccine in clinical trials has been shown to decrease invasive Strep. pneumo. infections by > 93%, serious pneumonia infections by 73% and a 7-10 % decrease in the rate of ear infections has been observed. A 20 % decrease in the need for placement of tympanostomy tubes (ear tubes) has occurred with administration of this vaccine. Prevnar vaccine was also shown to be more effective than antibiotic prophylaxis in decreasing the rate of nasopharyngeal carriage of this bacterium.⁶  With the increasing rates of antibiotic resistance of pneumococcal acute ear infections, it is especially appealing to be able to decrease rates of ear infections through vaccination. Side effects to the Prevnar vaccine tend to be mild including local injection site reactions, irritability, drowsiness, decreased appetite and low grade fever.⁴

It is very important as a parent that you ensure your child's immunizations are up to date as part of maintaining their overall good health. Make sure your child keeps appointments for well child check-ups. It is also important to keep a record of your child's immunizations. When your child begins school, the school will likely require a copy of this record.

Again though the rate of infection by many of the diseases we immunize against is very low in the U.S., they are still common in other parts of the world. Travelers can bring these diseases into the U.S. This is an issue here in Telluride where every day there are visitors from around the country and around the world. Without immunizations, these infections could rapidly spread. The Prevnar vaccine, as well as, all the vaccines mentioned in this article are available at the Telluride Medical Center.

References

1. What would happen if we stopped vaccinations? CDC National Immunization Program.
2. Achievements in Public Health, 1900-1999 Impact of Vaccines Universally Recommended for Children- United States, 1990-1998. MMWR Weekly. April 2, 1999/48(12);243-248.
3. Clinical Pharmacology 2000- Customized Monograph: Pneumococcal vaccine, polyvalent.
4. First Pneumococcal Vaccine for Infants and Toddlers. Clinical Briefs. AAFP. April 1, 2000.
5. AAP Recommends Pneumococcal Vaccine for children under 2. AAP Press Release. June 6, 2000.
6. AAP. Committee on Infectious Diseases Technical Report: Prevention of Pneumococcal infections, including the use of pneumococcal conjugate and polysaccharide vaccines and antibiotic prophylaxis. Overturf, GD. Pediatrics, 2000 Aug; 106:367-76.
7. Immunizations: What You Need to Know. AAP. 2001.