IOSR Journal of Dental and Medical Sciences (IOSR-JDMS) e-ISSN: 2279-0853, p-ISSN: 2279-0861.Volume 23, Issue 2 Ser. 4 (February. 2024), PP 65-74 www.iosrjournals.org DOI: 10.9790/0853-2302046574 www.iosrjournals.org 65 | Page Antibody Status After a Booster Dose of Vaccine Against SARS-CoV-2 Among the Healthcare Providers of Bangabandhu Sheikh Mujib Medical University(BSMMU) Khaja Badruddza 1* , Mohammad Masum Alam 2 , Sifat Naisum Rahman 3 , Shahriar Habib 4 , Farzana Islam 5 , Md. Hanif Howlader 6 , Forhadul Hoque Mollah 7 1* Department of Biochemistry, Sher-E-Bangla Medical College, Barishal, Bangladesh 2 Department of Biochemistry & Molecular Biology, BSMMU, Dhaka, Bangladesh 3 Department of Biochemistry, Sheikh Sayera Khatun Medical College, Gopalganj, Bangladesh 4 Department of Microbiology, Sher-E-Bangla Medical College, Barishal, Bangladesh 5 Laboratory Service Division, Sheikh Hasina National Institute of Burn & Plastic Surgery, Dhaka, Bangladesh 6 Department of Biochemistry, Sher-E-Bangla Medical College, Barishal, Bangladesh 7 Department of Biochemistry & Molecular Biology, BSMMU, Dhaka, Bangladesh Abstract: Background: COVID-19 was highly pathogenic, transmissible, and threatened human life. Antibodies produced after vaccination played a vital role in patients' survival-reducing morbidity and mortality. The study showed the response to vaccines among healthcare providers and revealed the picture of antibody status which can encourage people to receive the booster dose of vaccines. This study also showed the path of immunological protection through a booster dose of vaccination. Materials and Methods: The study was a prospective observational study that was conducted in the Department of Biochemistry and Molecular Biology, BSMMU, Dhaka, Bangladesh, from 1 st March 2022 to 28 th February 2023. According to inclusion and exclusion criteria, a total of 73 study subjects were selected for this study by convenience purposive sampling technique from the different departments of BSMMU. Results: Before taking the booster dose against SARS-CoV-2 the median Anti-RBD IgG of SARS-CoV-2 level was 3117.30 Au/mL and three weeks after taking the booster dose the median Anti-RBD IgG was 12174.20 Au/mL. The antibody level was increased about 4 times following the booster dose. Both homologous booster and heterologous booster showed similar immune responses regardless of the vaccine regimen. Hypertensive participants produced fewer antibodies, 7790.00 Au/mL following booster dose compared to normotensive participants, 14665.50 Au/mL. Diabetic participants also produced fewer antibodies, 7092.25 Au/mL following booster dose compared to nondiabetic participants, 12713.30 Au/mL. However, both hypertensive as well as diabetic participants produced robust antibodies following booster doses. Moderna vaccine produced significantly higher levels of IgG (5175.40 Au/mL) compared to AstraZeneca (2385.70 Au/mL) (Adjusted p-value 0.032 < 0.05) and Sinopharm (1828.15 Au/mL) (Adjusted p-value 0.009 < 0.05). Conclusion: A booster dose of vaccine against SARS-CoV-2 produced robust antibodies in healthy participants as well as participants with co-morbidities like hypertension and diabetes mellitus. Keywords: SARS-CoV-2, Anti-RBD IgG, COVID-19 Vaccine, Homologous and Heterologous Booster Dose. --------------------------------------------------------------------------------------------------------------------------------------- Date of Submission: 09-02-2024 Date of Acceptance: 19-02-2024 --------------------------------------------------------------------------------------------------------------------------------------- I. Introduction The most effective strategy to combat COVID-19 was found to be the preventive strategy by appropriate vaccines that primed the immune system before the first encounter with SARS-CoV-2 1 . Mass vaccination was considered the primary strategy to curtail this pandemic 2 with the ultimate goal of achieving herd immunity by fulfilling nearly 75-90% vaccination coverage 3 . SARS-CoV-2 or Severe Acute Respiratory Syndrome Coronavirus 2 is an enveloped, positive-sense, single-stranded RNA virus with crown-like appearance and a genome that encodes 4 viral structural proteins: spike, envelope, membrane, and nucleocapsid 4 , among them spike proteins help the virus to enter host cells by binding to the main virus receptor- angiotensin-converting enzyme 2 (ACE2), and thus a promising target for the development of mRNA vaccines 5–7 . Immunization against SARS- CoV-2 is believed to elicit a strong immune response against the virus's spike protein, specifically its receptor binding domain (RBD) 8 .