Serum Antibodies SARS-CoV-2 Spike (S) Protein Receptor-Binding Domain in OBGYN Residents and Effectiveness 3 Months after COVID-19 Vaccination

ABSTRACT

BACKGROUND: The health care workers are considered as vulnerable people who had higher infecting dose of SARS-CoV-2 infection compared to other society. Among more than 500 deaths of Indonesians physicians, obstetrics and gynecologist (OBGYN) has become the most specialists who died in this pandemic. AIM: The objective of our study is to evaluate the antibodies of SARS-CoV-2 in serum OBGYN residents post-vaccination as well as the presence of infection 3 months after the vaccination. METHODS: A prospective cohort study was conducted in OBGYN residents Universitas Indonesia. Serum antibodies SARS-CoV-2 spike (S) protein receptor-binding domain (RBD) was measured using electrochemiluminescence immunoassay, 21 days after Sinovac vaccination, with basic characteristics being recorded. Within 3 months follow-up, the participants were monthly checked related to post-vaccination infection. RESULTS: The median antibodies SARS-CoV-2 for all participants were 50.72 (19.09–98.57) U/mL. There were 20 residents (24.1%) who had post-vaccination infection within 3 months and dominated by asymptomatic to mild symptoms. Body mass index (r = –0.221, p = 0.044) and sleep hours (r = –0.225, p = 0.041) were found to be inversely correlated with antibodies SARS-CoV-2 S RBD. CONCLUSION: Antibodies SARS-CoV-2 S RBD found to be correlated with BMI and sleep hours. The 3-month post-vaccine infection among OBGYN residents was almost similar to Jakarta’s positivity rate and the efficacy rate was higher than expected by National Agency of Drug and Food Control.