Kuala Lumpur, 18 January 2022 - SINOVAC Biotech Ltd. (NASDAQ: SVA) ("SINOVAC" or the "Company") released new data that shows that 95% of individuals who have received three doses of CoronaVac® possess neutralising antibodies against Omicron. The study, posted on bioRxiv, was conducted in China and examined the immune response of CoronaVac®, a β-propiolactone-inactivated vaccine, in 120 participants.
Results from the study supported the use of a three-dose immunisation regimen as the seroconversion rates of neutralizing antibodies against Omicron jumped from 3.3% (2/60) to 95% (57/60) for two- and three-dose schedules respectively.1 In those participants who received three-doses, researchers also isolated 323 human monoclonal antibodies derived from memory B cells, half of which recognise the receptor binding domain (RBD) and show that a subset of them (24/163) provide neutralisation of SARS-CoV-2 variants of concerns (VOCs).1 The World Health Organization (WHO) designates a variant as a VOC if it is associated with “increase in transmissibility or detrimental change in COVID-19 epidemiology, increase in virulence or change in clinical disease presentation, or decrease in effectiveness of public health and social measures or available diagnostics, vaccines, therapeutics”.
Pearson LIU, spokesperson for SINOVAC, commented, “As the world continues to combat the emergence of new COVID-19 variants, this study provides reassurance that inactivated vaccines, one of the most widely used vaccines globally, remain effective in the fight against COVID-19. The results support a three-dose immunisation regimen to ensure greater protection against COVID-19, a finding which aligns with the advice of the WHO and local health authorities around the world for all types of COVID-19 vaccines.”
These latest data come in the wake of recent findings that show one-month after the second dose, CoronaVac® elicits a significantly higher T-cell response, which is important in preventing serious illness, hospitalisation and death, compared to a mRNA vaccine. The findings, which were published in December 2021, are from a study conducted by the LKS Faculty of Medicine, The University of Hong Kong (HKUMed) and the Faculty of Medicine, The Chinese University of Hong Kong (CU Medicine).
CoronaVac® has been approved for emergency use or conditional marketing use by local drug regulatory authorities and the WHO in more than 50 countries and regions and more than 2.6 billion doses of the vaccine had been delivered worldwide with over 250 million CoronaVac® doses administered in children aged 3 to 17 in China, as of January 2022. It is a widely used, well-tolerated, safe and effective vaccine and an important public health weapon to fight against the pandemic. Data from multiple clinical trials show that CoronaVac® is associated with minimal incidences of serious adverse events.
