Serologic response does not differ between patients initiating the pneumococcal vaccine series at 3 months post-allogeneic hematopoietic stem cell transplant (HCT) compared with those initiating the series at 6 months post-HCT, according to research published in the Journal of Oncology Pharmacy Practice.
“Current guidelines for patients undergoing allogeneic-HCT recommend the pneumococcal conjugate vaccine (PCV13) as a three-dose series followed by a single dose of the pneumococcal polysaccharide vaccine (PPSV23),” the researchers explained in their report. “Prior to June 2017, the pneumococcal vaccine series was initiated at six months post-HCT at the University of California San Diego Health (UCSDH). In June 2017, the vaccine policy was revised, and the pneumococcal vaccine series was initiated earlier at three months post-HCT.”
The researchers conducted a single-center, retrospective, observational chart review to evaluate the impact of initiating the pneumococcal vaccine series at 3 months post-HCT compared with 6 months post-HCT. The primary endpoints were vaccine response defined as a percentage of patients with a serologic response of >1 and >1.3 µg/mL for over 50% of the defined serotypes (1, 3, 4, 8, 9(9N), 12(12F), 14, 19(19F), 23(23F), 26(6B), 51(7F), and 56(18C)).
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A total of 129 patients, 23 who received vaccination at 3 months post-HCT and 106 who received vaccination at 6 months post-HCT (median age, 41 years and 55 years, respectively; P =.23), were included the study.
The researchers found no significant difference in the percentage of patients with a serologic response of >1 or >1.3 μg/mL for over 50% of the defined serotypes in the 3-month post-HCT and 6-month post-HCT groups (>1 μg/mL: 95.7% vs 78.3%; P =.07; >1.3 μg/mL: 78.3% vs 75.5%; P =0.78).
The findings were confirmed in a multivariable logistic regression analysis adjusted for variables associated treatment group that demonstrated no association between treatment group and outcome (odds ratio, 0.15; 95% CI, 0.02–1.24; P =.08).
There were also no significant differences in secondary outcomes (percentage of patients with a serologic response >1 μg/mL for 70% of the defined serotypes, proper administration of the vaccine series, incidence of infection post-HCT, or use of steroids and IVIG administration) between the groups.
“Our study found no statistically significant differences in serologic response or hospital outcomes between the two groups, suggesting that it is feasible to start the pneumococcal vaccine series at three months post-HCT in this high-risk population,” the researcher concluded.
Limitations of the study included the retrospective, nonrandomized design, small sample size, an imbalance in the number of patients in each group, and use of surrogate markers to define vaccine response.
Reference
Cheplowitz H, Patel N, Kim A, et al. Vaccine response after pneumococcal vaccination in allogeneic hematopoietic stem cell transplant recipients. J Oncol Pharm Pract. Published online March 22, 2023. doi:10.1177/10781552231165733
