A Systematic Review and Meta-Analysis of Serologic Response following Coronavirus Disease 2019 (COVID-19) Vaccination in Solid Organ Transplant Recipients.

Solid organ transplant (SOT) recipients are at greater risk of coronavirus disease 2019 (COVID-19) and have attenuated response to vaccinations. In the present meta-analysis, we aimed to evaluate the serologic response to the COVID-19 vaccine in SOT recipients. A search of electronic databases was conducted to identify SOT studies that reported the serologic response to COVID-19 vaccination. We analyzed 44 observational studies including 6158 SOT recipients. Most studies were on mRNA vaccination (mRNA-1273 or BNT162b2). After a single and two doses of vaccine, serologic response rates were 8.6% (95% CI 6.8-11.0) and 34.2% (95% CI 30.1-38.7), respectively. Compared to controls, response rates were lower after a single and two doses of vaccine (OR 0.0049 [95% CI 0.0021-0.012] and 0.0057 [95% CI 0.0030-0.011], respectively). A third dose improved the rate to 65.6% (95% CI 60.4-70.2), but in a subset of patients who had not achieved a response after two doses, it remained low at 35.7% (95% CI 21.2-53.3). In summary, only a small proportion of SOT recipients achieved serologic response to the COVID-19 mRNA vaccine, and that even the third dose had an insufficient response. Alternative strategies for prophylaxis in SOT patients need to be developed. Key Contribution: In this meta-analysis that included 6158 solid organ transplant recipients, the serologic response to the COVID-19 vaccine was extremely low after one (8.6%) and two doses (34.2%). The third dose of the vaccine improved the rate only to 66%, and in the subset of patients who had not achieved a response after two doses, it remained low at 36%. The results of our study suggest that a significant proportion of solid organ transplant recipients are unable to achieve a sufficient serologic response after completing not only the two series of vaccination but also the third booster dose. There is an urgent need to develop strategies for prophylaxis including modified vaccine schedules or the use of monoclonal antibodies in this vulnerable patient population.

Serologic response following SARS-COV2 vaccination in patients with cancer: a systematic review and meta-analysis.

PURPOSE: Patients with cancer have an increased risk of coronavirus disease 2019 (COVID-19) and an attenuated responses to various vaccines. This meta-analysis aims to assess the serologic response to COVID-19 vaccination in patients with cancer. METHODS: Electronic databases were systematically searched on August 1, 2021 for studies that reported the serologic response to COVID-19 vaccine in cancer patients. Random effects models were used to achieve pooled serologic response rates and odds ratios (ORs). RESULTS: We analyzed 16 observational studies with a total of 1453 patients with cancer. A majority of studies used mRNA vaccines (BNT162b2 or mRNA-1273). The proportion of patients achieving a serologic response after a single and two doses of COVID-19 vaccine were 54.2% (95% confidence interval [CI] 41.0-66.9) and 87.7% (95% CI 82.5-91.5), respectively. Patients with hematologic cancers had a lower response rate after the second dose of vaccine compared to those with solid organ cancers (63.7% vs. 94.9%), which was attributable to the low response rates associated with certain conditions (chronic lymphocytic leukemia, lymphoma) and therapies (anti-CD20, kinase inhibitors). A lower proportion of patients with cancer achieved a serologic response compared to control patients after one and two doses of vaccine (OR0.073 [95% CI 0.026-0.20] and 0.10 [95% CI 0.039-0.26], respectively). CONCLUSIONS: Patients with cancer, especially those with hematologic B-cell malignancies, have a lower serologic response to COVID-19 vaccines. The results suggest that cancer patients should continue to follow safety measures including mask-wearing after vaccination and suggest the need for additional strategies for prophylaxis.

Serologic Response to Coronavirus Disease 2019 (COVID-19) Vaccination in Patients With Immune-Mediated Inflammatory Diseases: A Systematic Review and Meta-analysis.

BACKGROUND & AIMS: Patients with immune-mediated inflammatory diseases (IMIDs) have an increased risk of coronavirus disease 2019 (COVID-19), primarily attributed to the use of immunosuppressive drugs such as glucocorticoids, which may attenuate the response to vaccines. This meta-analysis assessed the serologic response to COVID-19 vaccination in patients with IMIDs. METHODS: Electronic databases were searched on August 1, 2021, for observational studies. Data extracted included reference population, medications, vaccination, and proportion of patients achieving a serologic response. RESULTS: The analysis included 25 observational studies (5360 patients). Most of the studies used messenger RNA (mRNA) vaccines (BNT162b2, mRNA-1273), with a small number of studies including other types of vaccines (AZD1222, CoronaVac, BBV152, Ad26.COV2.S). Serologic response after 1 dose (6 studies) and 2 doses (17 studies) of mRNA vaccine were 73.2% (95% confidence interval [CI], 65.7%-79.5%) and 83.4% (95% CI, 76.8%-88.4%), respectively. On meta-regression, anti-CD20 therapy was associated with lower response rates (P < .001) and anti-tumor necrosis factor therapy also showed a trend toward lower response rates (P = .058). Patients with IMIDs were less likely to achieve a serologic response compared with controls after 2 doses of mRNA vaccine (6 studies; odds ratio, 0.086; 95% CI, 0.036-0.206; P < .001). There were not enough studies to assess response to the adenoviral or inactivated vaccines. CONCLUSIONS: Our meta-analysis demonstrated that patients with IMIDs have a reduced response to mRNA COVID-19 vaccines. These results suggest that IMID patients receiving mRNA vaccines should complete the vaccine series without delay and support the strategy of providing a third dose of the vaccine.