Which of the following statements about PCV13 pneumococcal vaccine candidates is true?

The statement that aligns with the accurate understanding of PCV13 vaccine candidates asserts that certain candidates are indeed successful in providing immunity against pneumococcal disease, while others are not applicable or relevant to the PCV13’s specific indications or effectiveness.

PCV13 (Pneumococcal Conjugate Vaccine) is designed to protect against infections caused by 13 types of Streptococcus pneumoniae bacteria. This vaccine is crucial in preventing pneumonia, meningitis, and sepsis, particularly in vulnerable populations such as young children and older adults. It is built on scientific findings that confirm its efficacy against certain serotypes of pneumococci known to cause serious illnesses.

In the context of the choices provided, acknowledging that some candidates pertain positively (Yes) while others do not (No) helps clarify the potential landscape of pneumococcal vaccine candidates. The classification by yes and no reflects the understanding of the vaccine's targeted effectiveness and the rationale behind its development and continued usage in public health initiatives.