The pneumococcal conjugate vaccine (PCV) can be used to prevent some -- but not all -- cases of ear infections. The PCV shot prevents infections of Streptococcus pneumoniae a group of bacteria that in addition to ear infections also causes pneumonia and meningitis in small children. Because the shot only protects against the 13 most common types of Streptococcus pneumoniae, a child can still get ear infections caused by other microorganisms (bacteria and viruses) after having the vaccination. The PCV shot is part of the routine vaccination schedule for children under the age of 5 but is not recommended for children or adults over the age of 5 unless they have a cochlear implant, or a weak immune system. In the case of the latter, those children often receive an even broader pneumococcal vaccine than PCV.
Ear infections are often caused by other infections like colds or the flu. Keeping your child's immunizations, including PCV, up-to-date can go a long way in preventing ear infections, but your child may still get an ear infection regardless. More information can be found about the pneumococcal conjugate vaccine, including side effects and contraindications on the CDC's website.
In addition to approved vaccinations, researchers are trying to develop new vaccines to prevent ear infections.
Centers for Disease Control and Prevention. Vaccine Information Statements. PCV13 and PCV7. Accessed: March 18, 2011 from http://www.cdc.gov/vaccines/pubs/vis/default.htm#pcv
Immunization Action Coalition. Ask the Experts: Pneumococcal Conjugate Vaccine. Accessed: March 18, 2011 from http://www.immunize.org/askexperts/experts_pcv.asp