In high-risk patients, which doses are administered for PCV 13 and PCV 23 vaccines?
a) PCV 13 - 2 doses; PCV 23 - 1 dose
b) PCV 13 - 1 dose; PCV 23 - 2 doses
c) PCV 13 - 3 doses; PCV 23 - 2 doses
d) PCV 13 - 2 doses; PCV 23 - 3 doses