Final answer:
Pneumococcal infections typically occur more frequently during colder months and in individuals with weakened immune systems or existing lung diseases. Vaccines are available to protect vulnerable populations.
Step-by-step explanation:
Pneumococcal infections, such as pneumococcal pneumonia and pneumococcal meningitis, are most commonly caused by the bacterium Streptococcus pneumoniae. These infections can occur at any time, but they tend to be more common during the cold months when respiratory diseases like the flu are prevalent. They are more likely to develop in people with a compromised immune system, existing lung diseases, or in extreme ages—very young children and the elderly. The availability of vaccines, including the pneumococcal conjugate vaccine (PCV13) and the pneumococcal polysaccharide vaccine (PPSV23), has been instrumental in protecting the most vulnerable populations from pneumococcal diseases.