Assessment on anti-SARS-CoV-2 receptor-binding domain antibodies among CoronaVac-vaccinated Indonesian adults

Abstract

The immunogenicity of CoronaVac among Indonesian adults at the academic premises was investigated. Two doses of CoronaVac vaccine induced a complete seroconversion on severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) naïve adults with titers of anti-SARS-CoV-2 receptor-binding domain (RBD) antibodies ranging from 9.1 to 151.9 U/mL. The median value was lower than the one observed in recovered adults with mild coronavirus disease 2019 (38.7 vs. 114.5 U/mL). Nonetheless, 93.6% of the vaccinated adults, in contrast to 76.5% of the recovered adults, displayed inhibition rates above the cut-off to block RBD-angiotensin-converting enzyme 2 binding. This suggests that two doses of CoronaVac were immunogenic and likely to be protective among Indonesian adults.

Heterologous prime-boost with the mRNA-1273 vaccine among CoronaVac-vaccinated healthcare workers in Indonesia

“…An approximately 700-fold increase was observed in the titers measured 28 days post-booster vaccination, from the ones measured a week before booster vaccination. We quantified the titer of anti-SARS-CoV-2 RBD antibodies as these antibodies could block the viral entry into host cells [ 3 ] and as several groups, including ours, had reported a highly linear association between the titer of anti-SARS-CoV-2 RBD antibodies and percentage of inhibition in RBD–ACE-2 binding via various neutralization assays [ 20 21 ]. The increment in titer of anti-SARS-CoV-2 RBD antibodies post-booster with the mRNA-1273 vaccine was in line with the previous publication, reporting that the mRNA-1273 vaccination generated robust humoral and cellular immune responses toward spike protein of SARS-CoV-2 [ 14 ].…”

Emergence of the SARS-CoV-2 Omicron Variant: Current Treatments and Vaccines for COVID-19

“…83 All three inactivated vaccines induced humoral immunity and provided an adequate protection from severe COVID-19 and death (but not mild/moderate illness) after completing two doses of vaccination. [84][85][86][87][88][89] The effectiveness of two doses of CoronaVac vaccination in Hong Kong in terms of protection against severe illness and death among younger adults of 20-59 and >60 years old were 91.7% and 71.1%, respectively. 90 The common adverse events were mostly mild to moderate, including pain at the injection site, fatigue, fever, headache and swelling.…”

SARS-CoV-2 Breakthrough Infection after mRNA-1273 Booster among CoronaVac-Vaccinated Healthcare Workers

“…CoronaVac (Sinovac Life Sciences, Beijing, China), which is an inactivated severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine, was utilized in the coronavirus disease 2019 (COVID-19) emergency vaccination program for healthcare workers (HCWs) in Indonesia [ 1 ]. The protective antibody titers induced by two doses of CoronaVac were noted to be relatively low and significantly waned over 6 months [ 2 3 ]. This has prompted the Ministry of Health of the Republic of Indonesia to provide one dose (100 μg) of mRNA-1273 vaccine (Moderna, Inc., Cambridge, MA, USA) for the Indonesian HCWs since mid-July 2021.…”

“…Higher titers of anti-S antibodies upon vaccination, including anti S-RBD antibodies, were correlated with a better protection against SARS-CoV-2 infection, both in adults and elderlies [ 2 7 9 10 ]. The neutralizing activity of those antibodies were reduced against the Omicron, however, than against the original, Beta or Delta variant [ 7 9 10 ].…”