Current best evidence for clinical care (more info)
BACKGROUND: In the general population, the seroconversion rate after primary vaccination with two doses of an anti-severe acute respiratory syndrome coronavirus 2 messenger RNA (mRNA) vaccine reaches nearly 100%, with significantly higher antibody titers after mRNA-1273 vaccination compared to BNT162b2 vaccination. Here we performed a systematic review and meta-analysis to compare the antibody response after two-dose mRNA-1273 versus BNT162b2 vaccination in solid organ transplant (SOT) recipients.
METHODS: A systematic literature review was performed using PubMed, Web of Science and the Cochrane Library and original research papers were included for a meta-analysis to calculate vaccine-specific seroconversion rates for each of the mRNA vaccines. Next, the pooled relative seroconversion rate was estimated.
RESULTS: Eight studies that described the development of antibodies against receptor-binding domain (RBD) and/or spike protein were eligible for meta-analysis. Two of these studies also reported antibody titers. The meta-analysis revealed lower seroconversion rates in SOT recipients vaccinated with two doses of BNT162b2 {44.3% [95% confidence interval (CI) 34.1-54.7]} as compared with patients vaccinated with two doses of mRNA-1273 [58.4% (95% CI 47.2-69.2)]. The relative seroconversion rate was 0.795 (95% CI 0.732-0.864).
CONCLUSIONS: This systematic review and meta-analysis indicates that in SOT recipients, higher seroconversion rates were observed after vaccination with mRNA-1273 compared with BNT162b2.
| Discipline / Specialty Area | Score |
|---|---|
| Internal Medicine | |
| Gastroenterology | |
| Nephrology | |
| Respirology/Pulmonology | |
| Infectious Disease | |
The final paragraph is salient, for much has been made of antibody response to vaccination as a surrogate marker of vaccine efficacy. This may or may not be appropriate. The authors state: "the seroconversion rate appeared to be higher after mRNA-1273 vaccination versus BNT162b2 vaccination in SOT recipients." The authors then state: "Future studies are needed to assess whether these differences are confirmed after third-dose vaccination and whether they also associated with a better protection against severe disease, hospitalization and/or mortality."
There is concern with desensitization regarding Covid and vaccinations, but this a clinically relevant article for which all physicians should be aware.
I believe both vaccines are efficacious but if one is superior, that would be good to know. Mortality in transplant recipients is high, but is improving with multiple boosters.
This meta-analysis/systematic review appears to confirm what we already believed to be true: mRNA vaccines against Covid are more effective than other vaccines in recipients of solid organ transplants.