{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,30]],"date-time":"2026-07-30T09:53:21Z","timestamp":1785405201139,"version":"3.56.0"},"reference-count":36,"publisher":"MDPI AG","issue":"7","license":[{"start":{"date-parts":[[2026,6,27]],"date-time":"2026-06-27T00:00:00Z","timestamp":1782518400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100004595","name":"Universiti Sains Malaysia","doi-asserted-by":"publisher","award":["304\/PPSP\/6150231\/M178"],"award-info":[{"award-number":["304\/PPSP\/6150231\/M178"]}],"id":[{"id":"10.13039\/501100004595","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100004595","name":"Universiti Sains Malaysia","doi-asserted-by":"publisher","award":["304\/PPSP\/6150217\/M178"],"award-info":[{"award-number":["304\/PPSP\/6150217\/M178"]}],"id":[{"id":"10.13039\/501100004595","id-type":"DOI","asserted-by":"publisher"}]},{"award":["304\/PPSP\/6150231\/M178"],"award-info":[{"award-number":["304\/PPSP\/6150231\/M178"]}],"id":[{"id":"https:\/\/ror.org\/02rgb2k63","id-type":"ROR","asserted-by":"publisher"}]},{"award":["304\/PPSP\/6150217\/M178"],"award-info":[{"award-number":["304\/PPSP\/6150217\/M178"]}],"id":[{"id":"https:\/\/ror.org\/02rgb2k63","id-type":"ROR","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["TropicalMed"],"abstract":"<jats:p>Neutralizing antibodies (NABs) play a critical role in assessing the immune response elicited by vaccines, providing insight into their protective efficacy. Despite their importance, there is a notable gap in research directly comparing NAB levels among individuals vaccinated with different vaccines, across diverse ethnicities, and between genders. The study aimed to compare NAB levels across variables such as vaccination status, vaccine type, age, gender, and ethnicity. The NAB levels among different study groups were measured using the Finecare RBD Antibody Test and the cPass kit (ELISA). The data was analyzed statistically using SPSS version 27. A total of 172 study subjects were analyzed. The mean age of participants was 45.03 \u00b1 16.72 years, with 50.9% male and 77.3% of Malay ethnicity. Median NAB levels, assessed by both assays, were highest in females, vaccinated healthy participants, and those who received the Pfizer vaccine. Age-group comparisons revealed variations in median NAB levels across studied groups. Participants aged 10\u201325 years in the vaccinated healthy (VH) group exhibited the highest median antibody levels; on the other hand, the 26\u201345 year age group showed the highest median levels in the breakthrough infection (BI) and certain non-vaccinated categories. Ethnic group comparisons highlighted that Malays consistently had the highest median NAB levels. Significant differences in antibody levels were found across vaccination status, ethnicity, and vaccine type (p &lt; 0.001). This study underscores the influence of vaccination status, demographic factors, and vaccine type on NAB levels. The Finecare RBD Antibody Test and cPass kit demonstrated comparable trends, highlighting their utility in evaluating vaccine-induced immunity. The findings of this study highlight the need for tailored immunization strategies to optimize protective immunity.<\/jats:p>","DOI":"10.3390\/tropicalmed11070178","type":"journal-article","created":{"date-parts":[[2026,6,29]],"date-time":"2026-06-29T02:16:44Z","timestamp":1782699404000},"page":"178","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Neutralizing Antibody Response Dynamics in COVID-19: Insights from Healthy Vaccinees, Breakthrough Infections, and Critically Ill Patients"],"prefix":"10.3390","volume":"11","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-1504-1705","authenticated-orcid":false,"given":"Naveed","family":"Ahmed","sequence":"first","affiliation":[{"name":"Department of Medical Microbiology and Parasitology, School of Medical Sciences, Universiti Sains Malaysia, Kubang Kerian 16150, Kelantan, Malaysia"},{"name":"Department of Emergency Medicine, School of Medical Sciences, Universiti Sains Malaysia, Kubang Kerian 16150, Kelantan, Malaysia"},{"name":"Department of Assistance Medical Science, Applied College, University of Tabuk, Tabuk 71491, Saudi Arabia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2574-6119","authenticated-orcid":false,"given":"Wardah","family":"Yusof","sequence":"additional","affiliation":[{"name":"Department of Medical Microbiology and Parasitology, School of Medical Sciences, Universiti Sains Malaysia, Kubang Kerian 16150, Kelantan, Malaysia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7533-8474","authenticated-orcid":false,"given":"Nurfadhlina","family":"Musa","sequence":"additional","affiliation":[{"name":"Human Genome Centre, School of Medical Sciences, Universiti Sains Malaysia, Kubang Kerian 16150, Kelantan, Malaysia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2125-7297","authenticated-orcid":false,"given":"Kueh Yee","family":"Cheng","sequence":"additional","affiliation":[{"name":"Biostatistics & Research Methodology Unit, School of Medical Sciences, Universiti Sains Malaysia, Kubang Kerian 16150, Kelantan, Malaysia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8851-9530","authenticated-orcid":false,"given":"Nurzulaikha","family":"Abdullah","sequence":"additional","affiliation":[{"name":"Biostatistics & Research Methodology Unit, School of Medical Sciences, Universiti Sains Malaysia, Kubang Kerian 16150, Kelantan, Malaysia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0493-1390","authenticated-orcid":false,"given":"Rosline","family":"Hassan","sequence":"additional","affiliation":[{"name":"Department of Hematology, School of Medical Sciences, Universiti Sains Malaysia, Kubang Kerian 16150, Kelantan, Malaysia"},{"name":"Hospital Universiti Sains Malaysia, Universiti Sains Malaysia, Kubang Kerian 16150, Kelantan, Malaysia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0006-2522-116X","authenticated-orcid":false,"given":"Muhammad Nashrul Farhan","family":"Samsudin","sequence":"additional","affiliation":[{"name":"Department of Medical Microbiology and Parasitology, School of Medical Sciences, Universiti Sains Malaysia, Kubang Kerian 16150, Kelantan, Malaysia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Alwi Muhd Besari","family":"Hashim","sequence":"additional","affiliation":[{"name":"Department of Internal Medicine, School of Medical Sciences, Universiti Sains Malaysia, Kubang Kerian 16150, Kelantan, Malaysia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5321-1344","authenticated-orcid":false,"given":"Manickam","family":"Ravichandran","sequence":"additional","affiliation":[{"name":"Faculty of Applied Sciences, Department of Biotechnology, AIMST University, Bedong 08100, Kedah, Malaysia"},{"name":"MyGenome, ALPS Global Holding Berhad, Kuala Lumpur 50400, Malaysia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Chua Wei","family":"Chuan","sequence":"additional","affiliation":[{"name":"Department of Medical Microbiology and Parasitology, School of Medical Sciences, Universiti Sains Malaysia, Kubang Kerian 16150, Kelantan, Malaysia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0034-7624","authenticated-orcid":false,"given":"Chan Yean","family":"Yean","sequence":"additional","affiliation":[{"name":"Department of Medical Microbiology and Parasitology, School of Medical Sciences, Universiti Sains Malaysia, Kubang Kerian 16150, Kelantan, Malaysia"},{"name":"Hospital Universiti Sains Malaysia, Universiti Sains Malaysia, Kubang Kerian 16150, Kelantan, Malaysia"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,6,27]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"277","DOI":"10.1186\/s12985-024-02546-0","article-title":"Comparative study of neutralizing antibodies titers in response to different types of COVID-19 vaccines among a group of egyptian healthcare workers","volume":"21","author":"Maher","year":"2024","journal-title":"Virol. 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