Comparison of safety and immunogenicity of CoronaVac and ChAdOx1 against the SARS-CoV-2 circulating variants of concern (Alpha, Delta, Beta) in Thai healthcare workers
Nasikarn Angkasekwinai,
Jaturong Sewatanon,
Suvimol Niyomnaitham,
Supaporn Phumiamorn,
Kasama Sukapirom,
Sompong Sapsutthipas,
Rujipas Sirijatuphat,
Orasri Wittawatmongkol,
Sansnee Senawong,
Surakameth Mahasirimongkol,
Sakalin Trisiriwanich,
Kulkanya Chokephaibulkit
Affiliations
Nasikarn Angkasekwinai
Department of Medicine, Faculty of Medicine Siriraj Hospital, Mahidol University, Thailand
Jaturong Sewatanon
Department of Microbiology, Faculty of Medicine Siriraj Hospital, Mahidol University, Thailand
Suvimol Niyomnaitham
Department of Pharmacology, Faculty of Medicine Siriraj Hospital, Mahidol University, Thailand; Siriraj Institute of Clinical Research (SICRES), Faculty of Medicine Siriraj Hospital, Mahidol University, Thailand
Supaporn Phumiamorn
Department of Medical Sciences, Ministry of Public Health, Thailand
Kasama Sukapirom
Biomedical Research Incubator Unit, Department of Research, Faculty of Medicine Siriraj Hospital, Mahidol University, Thailand; Siriraj Center of Research Excellence in Microparticle and Exosome in Disease, Thailand
Sompong Sapsutthipas
Department of Medical Sciences, Ministry of Public Health, Thailand
Rujipas Sirijatuphat
Department of Medicine, Faculty of Medicine Siriraj Hospital, Mahidol University, Thailand
Orasri Wittawatmongkol
Department of Pediatrics, Faculty of Medicine Siriraj Hospital, Mahidol University, Thailand
Sansnee Senawong
Department of Immunology, Faculty of Medicine Siriraj Hospital, Mahidol University, Thailand
Surakameth Mahasirimongkol
Department of Medical Sciences, Ministry of Public Health, Thailand
Sakalin Trisiriwanich
Department of Medical Sciences, Ministry of Public Health, Thailand
Kulkanya Chokephaibulkit
Siriraj Institute of Clinical Research (SICRES), Faculty of Medicine Siriraj Hospital, Mahidol University, Thailand; Department of Pediatrics, Faculty of Medicine Siriraj Hospital, Mahidol University, Thailand; Corresponding author at: Department of Pediatrics, Faculty of Medicine Siriraj Hospital, Mahidol University, Siriraj Institute of Clinical Research (SICRES), 2 Wanglang Road, Bangkoknoi, Bangkok 10700, Thailand.
Background: Inactivated vaccine (CoronaVac) and chimpanzee adenovirus-vector vaccine (ChAdOx1) have been widely used in resource-limited settings. However, the information on the reactogenicity and immunogenicity of these two vaccines in the same setting are limited. Methods: Healthy health care workers (HCWs) aged 18 years or older were randomly assigned to receive either two doses of CoronaVac at 4 weeks interval or two doses of ChAdOx1 at 10 weeks interval. Self-reported adverse events (AEs) were collected for 7 days following each vaccination. Immunogenicity was determined by IgG antibodies levels against receptor binding domain (RBD) of the SARS-CoV-2 spike protein (S1 subunit) and the 50% plaque reduction neutralization titers against various strains. Results: Of the 360 HCWs, 180 in each vaccine group, the median (interquartile range: IQR) age was 35 (29–44) years old and 84.2% were female. Participants who received ChAdOx1 reported higher frequency of AEs than those received CoronaVac after both the first dose (84.4% vs. 66.1%, P < 0.001) and second dose (75.6% vs. 60.6%, P = 0.002), with more AEs in those younger than 30 years of age for both vaccines. The seroconversion rates were 75.6% and 100% following the first dose of CoronaVac and ChAdOx1, respectively. All participants were seropositive at 2 weeks after the second dose. The anti-SARS-CoV-2 RBD IgG levels induced by CoronaVac was lower than ChAdOX1 with geometric means of 164.4 and 278.5 BAU/mL, respectively (P = 0.0066). Both vaccines induced similar levels of neutralizing antibodies against the Wuhan strain, with the titers of 337.4 and 331.2; however, CoronaVac induced significantly lower GMT against Alpha (23.1 vs. 92.5), Delta (21.2 vs. 69.7), and Beta (10.2 vs. 43.6) variants, respectively. Conclusion: CoronaVac induces lower measurable antibodies against circulating variants but with lower frequency of AEs than ChAdOx1. An earlier boosting to prevent breakthrough infections may be needed.
