Immunocompromised Get Effective But Less Protection from 2 mRNA COVID Vaccines, Notes New COVID VISION Project Research

Two doses of mRNA COVID-19 vaccines have been found to be effective in preventing laboratory-confirmed COVID-19 hospitalizations among patients who were immunocompromised (77%) and those who were immunocompetent (90%). Nonetheless, immunocompromised patients were less protected from severe COVID-19 compared with immunocompetent patients, and vaccine effectiveness varied considerably among immunocompromised patient subgroups, ranging from 59% among organ or stem cell transplant patients to 81% among patients with a rheumatologic or inflammatory disorder.

These findings support the recommendation that immunocompromised persons receiving mRNA COVID-19 vaccines should receive a 3rd dose and a booster, practice non-pharmaceutical interventions such as masking to prevent SARS-CoV-2 infection, and, if infected, be monitored closely and considered early for proven therapies that can prevent severe outcomes.

The new findings, Effectiveness of 2-Dose Vaccination with mRNA COVID-19 Vaccines Against COVID-19–Associated Hospitalizations Among Immunocompromised Adults — Nine States, January — September 2021, have been published in the Centers for Disease Control and Prevention’s (CDC’s) Morbidity and Mortality Weekly Report (MMWR).

The research was sponsored by CDC’s COVID VISION Project, which integrates medical, laboratory, pharmacy, and vaccination records to examine incidence, care trajectories, and outcomes associated with COVID-19 illness. Westat supports the clinical sites in this work. Our researchers were among the report’s coauthors: Matthew E. Levy, Ph.D.; Margaret M. Dunne, M.Sc.; Duck-Hye Yang, Ph.D.; Elizabeth A. Rowley, Dr.P.H.; Sarah W. Ball, Sc.D.; Patrick K. Mitchell, Sc.D.; Salome A. Kiduko, M.P.H.; Yan Zhuang, Ph.D.; Sarah E. Reese, Ph.D.