COVID-19 Evidence Alerts
from McMaster PLUSTM

Current best evidence for clinical care (more info)

Primary Prevention Galmiche S, Luong Nguyen LB, Tartour E, et al. Immunological and clinical efficacy of COVID-19 vaccines in immunocompromised populations: a systematic review. Clin Microbiol Infect. 2022 Feb;28(2):163-177. doi: 10.1016/j.cmi.2021.09.036. Epub 2021 Nov 17.
PICO Terms
adult (P) cancer patients (P) Comirnaty; Pfizer vaccine; BNT162b2; BioNTech/Fosun Pharma; mRNA (I/C) Covaxin vaccine; BBV152; Bharat Biotech; inactivated virus (I/C) hemodialysis (P) immunocompromised (P) immunogenicity (O) Johnson & Johnson vaccine; Janssen Pharmaceutical Companies; Ad26.COV2.S; non-replicating viral vector (I/C) non-responders (P) Novavax vaccine; NVX-CoV2373; protein subunit (I/C) Sinopharm vaccine; China National Biotec Group Company; Wuhan-WIV04; Beijing-HBO2; BBIBP-CorV; Vero Cells; inactivated virus (I/C) Sinovac vaccine; CoronaVac; inactivated virus (I/C) Spikevax; Moderna vaccine; mRNA-1273 SARS-CoV-2; ModernaTX; mRNA (I/C) vaccine effectiveness (O) vaccine efficacy (O) Vaxzevria; AstraZeneca vaccine; ChAd0x1 nCOV-19; non-replicating viral vector; adenovirus; University of Oxford/AstraZeneca; AZD1222 (I/C)

BACKGROUND: Available data show that COVID-19 vaccines may be less effective in immunocompromised populations, who are at increased risk of severe COVID-19.

OBJECTIVES: We conducted a systematic review of literature to assess immunogenicity, efficacy and effectiveness of COVID-19 vaccines in immunocompromised populations.

DATA SOURCES: We searched Medline and Embase databases.

STUDY ELIGIBILITY CRITERIA, PATIENTS, INTERVENTIONS: We included studies of COVID-19 vaccines after complete vaccination in immunocompromised patients until 31 August 2021. Studies with <10 patients, safety data only and case series of breakthrough infections were excluded.

METHODS: Risk of bias was assessed via the tool developed by the National Institutes of Health on interventional and observational studies. Immunogenicity was assessed through non-response rate defined as no anti-SARS-CoV-2 spike protein antibodies, efficacy and effectiveness by the relative reduction in risk of SARS-CoV-2 infection or COVID-19. We collected factors associated with the risk of non-response. We presented collected data by immunosuppression type.

RESULTS: We screened 5917 results, included 162 studies. There were 157 on immunogenicity in 25 209 participants, including 7835 cancer or haematological malignancy patients (31.1%), 6302 patients on dialysis (25.0%), 5974 solid organ transplant recipients (23.7%) and 4680 immune-mediated disease patients (18.6%). Proportion of non-responders seemed higher among solid organ transplant recipients (range 18-100%) and patients with haematological malignancy (range 14-61%), and lower in patients with cancer (range 2-36%) and patients on dialysis (range 2-30%). Risk factors for non-response included older age, use of corticosteroids, immunosuppressive or anti-CD20 agent. Ten studies evaluated immunogenicity of an additional dose. Five studies evaluated vaccine efficacy or effectiveness: three on SARS-CoV-2 infection (range 71-81%), one on COVID-19-related hospitalization (62.9%), one had a too small sample size.

CONCLUSIONS: This systematic review highlights the risk of low immunogenicity of COVID-19 vaccines in immunocompromised populations, especially solid organ transplant recipients and patients with haematological malignancy. Despite lack of vaccine effectiveness data, enhanced vaccine regimens may be necessary.

Discipline / Specialty Area Score
Oncology - Hematology
Public Health
Oncology - General
Infectious Disease
Hospital Doctor/Hospitalists
Internal Medicine
Comments from MORE raters

Gastroenterology rater

In this rapidly changing situation, a 6-month-old meta-analysis may not be relevant now with the impact of boosters, omicron, etc.

Gastroenterology rater

The trouble with interpreting this review is the significant conflict of interest several authors have with relevant pharmaceutical companies.

Infectious Disease rater

Relies heavily on observational studies and data already outdated.

Nephrology rater

At this time, this manuscript is probably relevant, although the results are not surprising.

Oncology - Hematology rater

Lack of immunogenicity to vaccines is widely known already, serves as a good summary but not newsworthy, in my opinion.

Public Health rater

This systematic review provides firsthand information about the response to Covid-19 vaccines while the pandemic is evolving in very specific populations. Patients who are immune compromised deserve special attention and must be advised and informed about the results of immunization. Close surveillance is warranted.

Rheumatology rater

High-quality review of available literature concerning vaccination response in immunocompromised populations. Relatively little data in rheumatic disease patients, and not enough information to contribute greatly to decision-making for these patients.