According to a recent study, those who are immunosuppressed, namely those who have had solid organ transplants, should receive additional booster doses of the COVID-19 vaccine.
The study, which was published in the Journal of Infectious Diseases, individuals who take immunosuppressive drugs to prevent organ transplant rejection have a higher risk of developing severe COVID-19 than people with healthy immune systems, even after receiving vaccination.
The study found that receiving three doses of an mRNA vaccine—the first two COVID-19 vaccines that have been approved for use in the United States are messenger RNA (mRNA) vaccines—led to much better protection than receiving only two doses.
Despite the study’s findings indicate patients on immunosuppressive drugs to prevent organ transplant rejection have a higher risk of developing severe COVID-19 than people with healthy immune systems, there is some positive news. The effectiveness of vaccination for transplant patients appears to be significantly increased by extra vaccine doses.
For instance, a regimen of three doses of the mRNA COVID-19 vaccine was 77% effective at preventing hospitalisation due to COVID-19 in transplant patients, compared to a regimen of two doses, which was only 29% effective.
The findings of this multicenter, real-world trial corroborate the CDC’s recommendations for a three-dose primary series in this at-risk population and show that solid organ transplant recipients benefit from receiving three doses of the mRNA COVID-19 vaccine.
In total, 10,425 hospitalised patients from 21 hospitals were examined in the study, including 440 solid organ transplant recipients, 1,684 patients with additional immunocompromising diseases, and 8,301 patients with healthy immune systems. The efficacy of fourth doses, the remaining risk of severe COVID-19 among solid organ transplant recipients after four vaccination doses, and the longevity of protection will all require further study.
Other precautions to lessen the incidence of COVID-19 among solid organ transplant recipients should also be taken into account, such as immunisation of close contacts, immunological monitoring of each individual, and infection protection techniques such face masking in public places and physical seclusion.
Parvathy Sukumaran 
