Sarscov-2 Antibody Response to COVID-19 MRNA Vaccine in 2024 among Health Care Workers Working in one Selected Public Hospital from Myanmar

Background: The health care workers have been handling with patients who may have symptomatic or asymptomatic coronavirus disease (COVID-19) since 2019. SARS-CoV-2 virus has been producing several variants. (Comirnaty) COVID-19 mRNA Vaccine (nucleoside modified) tozinameran was available in Myanmar in January 2024. This study aimed to assess changes in SARSCoV-2 antibody level in health care workers (HCW) following COVID-19 mRNA Vaccine and to determine the factors influencing antibody response. Methods: An analytic study was conducted in Defense Services General Hospital (1,000 Bedded) in Myanmar in 2024. SARSCoV-2 antibody level was measured twice; prior to COVID-19 mRNA Vaccine and 70 days after vaccination. Data were collected by using standardized forms and analysis was done. Results: A total of 99 HCW were included. All HCW had anti-Spike antibody prior to COVID-19 mRNA Vaccine (basal level); and the minimum level was 904 U/mL. Minimum antibody level as well as mean antibody level became double on Day ‘70’ after vaccination. Mean basal anti-Spike antibody level was 4,195.04 ± 2898.20 U/mL; it rose to 9,115.31± 3518.89 U/mL on Day ‘70’. Female had higher basal anti-Spike antibody level as well as the antibody level on Day ‘70’ than male; the basal level was 7,365 ± 5,460.97 U/mL and 3,878.04 ± 2,334.64 U/mL; and, ‘Day 70’ level was 10,404.67±4,725.860 U/mL and 8,894.85±3,487.904 U/mL respectively. HCW aged over 40 years had higher basal anti-Spike antibody level than that of under 40 years; 5,634.42 ± 3,801.08 U/mL and 3,538.85 ± 2,102.61 U/mL respectively. However, on Day ‘70’, younger age group had better response; 9,564.37±3,265.608 U/mL in younger age group and 7,864.55±4,098.874 U/mL in older age group. Antibody level on ‘Day 70’ was higher in HCW without comorbid disease and HCW with COVID symptoms at the time of vaccination. History of COVID-19 in past 6 months to 1 year prior to COVID-19 mRNA Vaccine did not influence the antibody response. The basal antibody level was lowest in underweight group (2,327.00±668.00 U/mL) and highest in overweight group 5,019.26±3,485.20 U/mL. On ‘Day 70’, the highest level 9,225.03±3,416.99 U/mL was recorded in normal weight group; it was followed by overweight group. Conclusions: All HCW had had acquired immunity to SARSCoV-2 virus in January 2024. Their SARSCoV-2 antibody level became double on Day ‘70’ after one dose of (Comirnaty) COVID-19 mRNA Vaccine (nucleoside modified) tozinameran. Younger age group, female, HCW without comorbid disease, those with normal weight and overweight group, and presence of COVID symptoms at the time of vaccination had better antibody response. Antibody response was not related with history of COVID-19 in past 6 months to 1 year. One dose of COVID-19 mRNA Vaccine was 100% effective in promoting anti-Spike antibody.