The most common type of bacterial pneumonia is called pneumococcal pneumonia. Pneumococcal pneumonia can be serious. Symptoms can come on quickly and can include cough, fatigue, high fever, shaking chills, and chest pain with difficulty breathing.

Certain people should get vaccinated against pneumococcal pneumonia, a common form of bacterial pneumonia including: Children younger than 2.

As pneumonia progresses, it has four stages: Congestion, red hepatization, gray hepatization, and resolution.

Bacteria are a common cause of pneumonia in adults. Many types of bacteria can cause pneumonia, but Streptococcus pneumoniae (also called pneumococcus bacteria) is the most common cause in the United States. Some bacteria cause pneumonia with different symptoms or other characteristics than the usual pneumonia.

People who need a pneumonia vaccine should get both shots: first, the PCV13 shot and then the PPSV23 shot a year or more later. For most people, one of each shot should be enough to protect them for their entire lives. Sometimes, you may need a booster shot. Ask your doctor whether you should get one.

CDC recommends routine administration of pneumococcal conjugate vaccine (PCV15 or PCV20) for all adults 65 years or older who have never received any pneumococcal conjugate vaccine or whose previous vaccination history is unknown: If PCV15 is used, this should be followed by a dose of PPSV23 one year later.

Hospital-acquired pneumonia. It can be serious because the bacteria causing the pneumonia can be resistant to antibiotics. You're more likely to get this type if: You're on a breathing machine. You can't cough strongly enough to clear your lungs.

It may take time to recover from pneumonia. Some people feel better and are able to return to their normal routines in 1 to 2 weeks. For others, it can take a month or longer.

It may take time to recover from pneumonia. Some people feel better and are able to return to their normal routines in 1 to 2 weeks. For others, it can take a month or longer.

Viruses that infect the respiratory tract may cause pneumonia. Viral pneumonia is often mild and goes away on its own within a few weeks. But sometimes it is serious enough that you need to get treatment in a hospital. If you have viral pneumonia, you are at risk of also getting bacterial pneumonia.

The pneumonia shot is especially recommended if you fall into one of these age groups: Younger than 2 years old: four shots (at 2 months, 4 months, 6 months, and then a booster between 12 and 15 months) 65 years old or older: two shots, which will last you the rest of your life.

Learn More: Pneumococcal Vaccines for Older Adults (Age 65+)