INTRODUCTION: Three doses of SARS-CoV-2 mRNA vaccines have been recommended for cancer patients to reduce the risk of severe disease. Anti-neoplastic treatment, such as chemotherapy, may affect long-term vaccine immunogenicity. METHOD: Patients with solid or haematological cancer were recruited from 2 hospitals between July 2021 and March 2022. Humoral response was evaluated using GenScript cPASS surrogate virus neutralisation assays. Clinical outcomes were obtained from medical records and national mandatory-reporting databases. RESULTS: A total of 273 patients were recruited, with 40 having haematological malignancies and the rest solid tumours. Among the participants, 204 (74.7%) were receiving active cancer therapy, including 98 (35.9%) undergoing systemic chemotherapy and the rest targeted therapy or immunotherapy. All patients were seronegative at baseline. Seroconversion rates after receiving 1, 2 and 3 doses of SARS-CoV-2 mRNA vaccination were 35.2%, 79.4% and 92.4%, respectively. After 3 doses, patients on active treatment for haematological malignancies had lower antibodies (57.3%±46.2) when compared to patients on immunotherapy (94.1%±9.56, P<0.05) and chemotherapy (92.8%±18.1, P<0.05). SARS-CoV-2 infection was reported in 77 (28.2%) patients, of which 18 were severe. No patient receiving a third dose within 90 days of the second dose experienced severe infection. CONCLUSION This study demonstrates the benefit of early administration of the third dose among cancer patients.
Humans ; SARS-CoV-2 ; COVID-19/prevention & control* ; Treatment Outcome ; Neoplasms/drug therapy* ; Hematologic Neoplasms ; Vaccination ; RNA, Messenger ; Antibodies, Viral ; Immunogenicity, Vaccine

Introduction:: Despite the improvement with blood screening, transfusion transmissible infections (TTI) remain a concern. In Brunei Darussalam, blood is collected based on voluntary non-remunerated blood donations. This study was carried out to determine the sero-prevalence of TTI in Brunei Darussalam based on blood donations collected over a five years period (2005 to 2009). Materials and Methods:: Blood donors were all screened for Hepatitis B virus (HBV), Hepatitis C virus (HCV), Syphilis (VDRL) and Human Immune Deficiency virus (HIV). Blood samples were collected and centrifuged before they were screened using Abbott ARCHITECT i2000SR analyser. Reactive samples were retested and confirmed with supplementary testing. Comparisons were made with published studies from 1988 and 1989. Result:: Out of 56,645 donation units, 874 donations units were positive (1.49%) for any of the screening tests: 520 (0.92%) for HBV, 175 (0.31%) for HCV, 173 (0.31%) for syphilis and 6 (0.01%) for HIV. A decreasing trend was noted for HBV from 1.15% to 0.53% (p<0.05) over the five years. For HCV, there was only a slight decreasing trend while there were increasing trends for syphilis and HIV. Compared to earlier studies, the current sero-prevalence of HBV was significantly lower (overall and per year, p values<0.001). Similarly, the sero-prevalence of VDRL was also significantly lower p<0.001). Conclusion: The sero-prevalence of HBV was the highest among all TTI. The rates are significantly lower than earlier studies. Of concern are the increasing trends of syphilis and HIV. Effective donor education including counseling of reactive donors, establishment of donor management system and introduction of nucleic acid testing may need to be introduced to reduce the incidence of TTI.