With treatment, most patients will improve within 2 weeks. Elderly or very sick patients may need longer treatment. Those who may be more likely to have complicated pneumonia include:
Older adults or very young children People whose immune system does not work well People with other, serious medical problems such as diabetes or cirrhosis of the liver
Your doctor may want to make sure your chest x-ray becomes normal again after you take a course of antibiotics. However, it may take many weeks for your x-ray to clear up.
What to expect if I have Streptococcus pneumoniae infection  (Outlook/Prognosis)?
With treatment, most patients will improve within 2 weeks. Elderly or very sick patients may need longer treatment. Those who may be more likely to have complicated pneumonia include:
Older adults or very young children People whose immune system does not work well People with other, serious medical problems such as diabetes or cirrhosis of the liver
Your doctor may want to make sure your chest x-ray becomes normal again after you take a course of antibiotics. However, it may take many weeks for your x-ray to clear up.