A routine pneumococcal vaccine is given to all persons at age 65 or shortly thereafter. Some people receive the vaccine earlier in life due to certain medical conditions that place them at higher risk. These people should then receive a second dose at some point after age 65.
A revaccination is not currently recommended for those who got their first dose at age 65 because evidence does not suggest that doing so provides better protection.
However, many of my colleagues will administer another dose every 5 years to their highest risk patients (severe medical problems such as lung disease, heart disease, cancer patients, etc) because they believe the small possible benefit outweighs the negligible risks.
So, simple answer, you don't need another dose but you should always discuss this with your doctor who knows your risks better than we do.