text: When compared with conventional attenuated vaccines and inactivated vaccines, recombinant subunit vaccines have the following special characteristics:
  * They contain clearly identified compositions which greatly reduces the possibility of presence of undesired materials within the vaccine.
  * Their pathogenicities are minimized as only fragments of the pathogen are present in the vaccine which cannot invade and multiply within the human body.
  * They have better safety profiles and are suitable to be administered to immunocompromised patients.
  * They are suitable for mass production due to the use of recombinant technologies.
  * They have high stability so they can withstand environmental changes and are more convenient to be used in community settings.
  However, there are also some drawbacks regarding recombinant subunit vaccines:
  * Addition of adjuvants is necessary during manufacturing to increase the efficacy of these vaccines.
  * Patients will have to receive booster doses to maintain long-term immunity.  
  * Selection of appropriate cell lines for the cultivation of subunits is time-consuming because microbial proteins can be incompatible to certain expression systems.