The National Comprehensive Cancer Network has suggested a fifth mRNA jab for people who are immunocompromised, including cancer patients. The advice came from NCCN advisory committee on Covid 19 vaccination and pre-exposure prophylaxis representing the fifth shot as a secondary booster. They explained that the primary vaccination regimen for immunocompromised patients involved three doses of Pfizer or Moderna vaccines. 

Advisory committee co-leader Lindsey Baden, MD, an infectious diseases specialist at the Dana-Farber Cancer Institute in Boston stated that they have a better understanding of Covid 19 and vaccinations now that can be used to provide better protection to cancer and immunocompromised patients.  

The advisory group also updated the dosing recommendation for pre-exposure protection with tixagevimab plus cilgavimab suggesting 300 mg of each monoclonal antibody instead of 150 mg, based on in vitro activity against Omicron variants along with the administration of Moderna and Pfizer shots, that can be used interchangeably for booster dosage. (Source: https://www.medscape.com/viewarticle/972864?src= )