There are two main reasons why you can still get the pneumonia vaccine if you have had pneumonia: 1. Pneumonia is an acute inflammation of the lung tissues caused by a variety of reasons, which can be seen in a variety of causes, including bacterial infections, viral infections, mycoplasma infections, chlamydia infections, etc. Pneumonia vaccine is mainly for the prevention of pneumonia caused by Streptococcus pneumoniae infection. Pneumonia vaccine is mainly for the prevention of pneumonia caused by Streptococcus pneumoniae infection, so if you have suffered from viral pneumonia or Mycoplasma pneumonia, or other bacterial infections caused by pneumonia, you still need to take the pneumonia vaccine to prevent Streptococcus pneumoniae infections. 2. Even if you have suffered from pneumonia caused by Streptococcus pneumoniae infections, there are many serotypes of Streptococcus pneumoniae, so if you have suffered from one type of Streptococcus pneumoniae, you may still get infected with other types of pneumoniae. It is possible to be infected again with another type of Streptococcus pneumonia. Moreover, the immunity developed after contracting Streptococcus pneumonia can only be maintained for a certain period of time, but not for a long time, so it is necessary to take the pneumonia vaccine as a preventive measure.