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2557 Neutralizing Antibody Responses in Patients with Hematological Malignancies after Omicron Infection: A Multicenter, Prospective Cohort Study in China

Program: Oral and Poster Abstracts
Session: 203. Lymphocytes and Acquired or Congenital Immunodeficiency Disorders: Poster II
Hematology Disease Topics & Pathways:
Research, clinical trials, Clinical Research, SARS-CoV-2/COVID-19, Diseases, Infectious Diseases
Sunday, December 10, 2023, 6:00 PM-8:00 PM

Li Jun, MD1*, Yi Liu1*, Xia Wei2*, Zhanshu Liu, MD3*, Zailiang Yang, MD4*, Ling Liu5*, Meiyu Zhou4*, Guofa Xu, MD4*, Lanting Chen3*, Yao Ding1*, Haike Lei6*, Zailin Yang1*, Shuang Chen1*, Xiaomei Zhang, PhD1*, Yifeng Tang1*, Yan Xiong1*, Jueyin Liu1*, Dehong Huang1*, Chunyan Xiao1*, Jun Liu1*, Tao Yang1*, Ying Xiang1*, Qiying Li1*, Yingyu Nan1*, Jieping Li1*, Yong Zhang, MD, PhD2*, Yongzhong Wu, MD, PhD7* and Yao Liu, PhD, MD1

1Department of Hematology-Oncology, Chongqing University Cancer Hospital, Chongqing, China
2Department of Hematology, the Third Affiliated Hospital of Chongqing Medical University, Chongqing, China
3Department of Hematology, Yongchuan Hospital of Chongqing Medical University, Chongqing, China
4Department of Hematology and Medical Oncology, Chongqing University Fuling Hospital, Chongqing, China
5Department of Medical Laboratory, People’s Hospital of Chongqing Liang Jiang New Area, Chongqing, China
6Department of Chongqing Cancer Multi-omics Big Data Application Engineering Research Center, Chongqing University Cancer Hospital, Chongqing, China
7Department of Radiation Oncology, Chongqing University Cancer Hospital, Chongqing, China


The mortality rate of hospitalized hematological malignancies (HM) patients with COVID-19 has significantly decreased from 40.7% in the pre-Omicron era (before December 2021) to 16.5% in the Omicron era (Blennow O, et al. AJH 2022; Pagano L, et al. JHO 2021). However, the mortality rate of Omicron infection in the general population is approximately 1%, which is comparable to influenza (Wang B, et al. J Infect 2023). Therefore, COVID-19 continues to pose a substantial threat to HM patients, even under the Omicron era. Neutralizing antibodies (NAbs) play a crucial role in preventing breakthrough infections and reinfections by blocking the entry of SARS-CoV-2 into the body (Nordstrom P, et al. Lancet Infect Dis 2022). However, little is known about neutralizing antibody (NAb) response development after natural Omicron infection and the risk factors for poor responders in HM patients.


A registered multi-center, prospective, observational study was conducted during the latest Omicron wave in Chongqing, China (November 2022 to January 2023). NAb titers (measured by serum IgG anti-receptor binding domain of spike protein [anti-S-RBD]) were assessed 3-6 weeks after infection in the HM cohort (HMC), healthy control cohort (HCC), and solid cancer cohort (SCC). The primary outcomes compared the anti-S-RBD IgG titer and seroconversion rate between the HMC and HCC or SCC. The exploratory outcome investigated risk factors for poor responders, defined as patients with non-seroconversion or low anti-S-RBD IgG titer, in the HMC.


Among the 466 HM patients in this cohort, the seroconversion rate was 92.7%, no statistically difference compared with HCC (98.2%, P=0.0513) or SCC (100%, P=0.1363); the median anti-S-RBD IgG titer was 29.9 ng/mL, significantly lower than HCC (46.9 ng/mL, P<0.0001) or SCC (46.2 ng/mL, P<0.0001). Risk factors associated with non-seroconversion included no COVID-19 vaccination history (OR=4.58, 95% CI: 1.75-12.00, P=0.002), clinical course of COVID-19 ≤ 7 days (OR=2.86, 95% CI: 1.31-6.25, P=0.008) and severe B-cell reduction (0-10/μL) (OR=3.22, 95% CI: 1.32-7.88, P=0.010); Risk factors associated with low anti-S-RBD IgG titer were clinical course of COVID-19 ≤ 7 days (OR=2.58, 95% CI: 1.59-4.18, P<0.001) and severe B-cell reduction (0-10/μL) (OR=2.87, 95% CI: 1.57-5.24, P<0.001).


This study reveals a poor NAb response in HM patients after Omicron (BA.5.2.48) infection and identifies risk factors for poor responders. Highlights that HM patients, especially those with these risk factors, may be susceptible to SARS-CoV-2 reinfection; and the post-infection vaccination strategies for these patients should be tailored.

Disclosures: No relevant conflicts of interest to declare.

*signifies non-member of ASH