Pneumococcal Vaccine

Dear Lisa,

My daughter is 21 months old. She still didn't get her last (4th) Pneumococcal Conjugate vaccine. Her doctor keeps telling me that it's O.K., that there is no rush with this one. Is that so?

Here is when my daughter had her previous PCV shots:

#1- when she was 2 months old
#2- when she was 4.5 months old
#3- when she was 12 months old

Should I worry that so much time already passed and the vaccine is still not done?

Should I tell the doctor to give the 4th shot at our next appointment?

“Pneumococcal Conjugate Vaccine”

Dear “Pneumococcal Conjugate Vaccine”,

When a child receives a vaccination her body mounts an immune response. The immune response results in the formation of antibodies or special white blood cells that fight a particular organism. If a child is exposed to that particular organism at a later date, she will be better equipped to fight the infection because the antibodies that are needed are already made and available.

When a child receives a vaccine at a young age, the immune response is not as effective as the immune response of an older child or an adult. Less antibodies are formed and the child is not as well equipped to fight the infection when exposed to it. Therefore, multiple vaccines are given to young infants in order to achieve antibody levels that are sufficient to combat the organism if it is encountered.

The companies that manufacture vaccines perform studies to determine the body’s immune response to vaccines given at specific ages. From this information, a vaccine schedule is recommended so that children will receive the greatest benefit from a vaccine. Following the vaccine schedule gives the child the opportunity to fight infections based on scientific research results.

If a vaccine schedule is not followed, a “catch up” schedule is recommended. The total number of actual injections given according to a “catch up” schedule may be different from the amount of injections given to a child who follows the recommended schedule. For many vaccines, fewer injections are needed if the vaccinations are given at an older age. The down side of this approach is that the young infant is not protected against the disease when they are most susceptible.

The recommended schedule for Prevnar or the Pneumococcal Conjugate Vaccine is three doses at approximately 2 month intervals, followed by a fourth dose at 12 to 15 months old. (1) The recommended dosing interval is 4 to 8 weeks. The fourth dose should be administered at least 2 months after the 3rd dose. (1)

The recommended schedule is as follows:

First Dose: 2 months
Second Dose: 4 months
Third Dose: 6 months
Fourth Dose: 12 – 15 months

The "catch up" schedule for Prevnar can be confusing. When a child misses a vaccination, the total recommended amount of injections changes. For example, if a child did not receive their first Prevnar immunization until they were 2 years old, then only one dose is recommended. (1) If a Child receives the first Prevnar vaccination between 7 and 11 months old, then only a total of 3 doses are recommended.

The schedule that you provided shows that your child missed the 3rd dose or the 6 month vaccination. According to the “catch up” schedule, Dose #3, when administered 8 weeks after dosage #2 is considered the “final” dose if it is given to a child that is greater than or equal to 12 months old. (2) Dose number 4 is only necessary for children aged 12 months to 5 years old who received 3 doses before the age of 12 months. Since your daughter is 21 months old and her 3rd dose was given at 12 months old, that dose would be considered her final dose. In her case, the 4th dose is not necessary.

So you do not have to worry that time has passed and you do not need to insist that the fourth dose be given now. At your daughter’s next scheduled visit, her Doctor should tell you if he recommends the fourth dose or not.

References:
(1)Physician’s Desk Reference. 2004. Montvale, NJ. Thomson PDR at Montvale:3471-3479.
(2)RedBook Online. Recommended Immunization Schedule for Children and Adolescents who start late or who are More than 1 month behind, 2007. Available at: http://www.aapredbook.org/. Accessed March 2007.

Lisa-ann Kelly R.N., P.N.P.,C.
Certified Pediatric Nurse Practitioner

Pediatric Advice About Keeping Children Healthy