Pandemic Special Access Route (PSAR) Interim Authorisation of CoronaVac for Active Immunisation to Prevent COVID-19 disease in Singapore

The Health Sciences Authority (HSA), in consultation with its Medicines Advisory Committee and Panel of Infectious Diseases Experts, would like to inform healthcare professionals that HSA has granted PSAR* interim authorisation for CoronaVac, an inactivated SARS-CoV-2 vaccine, by Sinovac Biotech. The vaccine is authorised under PSAR for active immunisation against COVID-19 in individuals 18 years of age and older.

HSA’s decision to grant PSAR interim authorisation for CoronaVac took into consideration that the level of evidence presented by the company narrowly met the minimum technical requirements for approving the vaccine for use during the pandemic given the urgent public health needs for a non-mRNA vaccine. The company is required to submit the complete dataset based on prevailing international standards for a full registration. 

The efficacy of CoronaVac against symptomatic disease was observed to be marginal. The Phase III study conducted in healthcare workers aged 18 years and above in Brazil (n = 9,823) showed that the vaccine had an efficacy of 50.7% and real-world evidence from an observational cohort study in Chile suggested an effectiveness of 65.9%. The neutralising antibody levels after vaccination with two doses of CoronaVac were low and they declined rapidly to baseline levels similar to that in unvaccinated persons within 6 months. There is no efficacy nor effectiveness data against the current variants of concern such as the delta variant. Studies of other COVID-19 vaccines with higher vaccine efficacy than CoronaVac had shown reduced effectiveness against the delta variant. Healthcare professionals should consider the potential for reduced vaccine efficacy or effectiveness of CoronaVac against variants of concern as well as the risks of inadequate protection when considering the use of the vaccine.

The safety analysis was based primarily on the data from the Phase I/II and Phase III clinical trials conducted in China and Brazil, respectively, among individuals aged 18 years and older. The most frequently reported adverse events (AEs) were fatigue, injection-site pain, headache, muscle pain, diarrhoea and nausea. Overall, the safety profile of the vaccine is mainly characterised by reactogenic events, which is consistent with what is known for COVID-19 vaccines. The frequency of anaphylaxis was estimated to be 1.3 events per 100,000 doses in the Chile observational cohort study. Based on local adverse events reported to date, the observed incidences were 1.8 events per 100,000 doses with CoronaVac compared with 0.87 events per 100,000 doses for mRNA vaccines.

HSA will continue to actively monitor and review post-marketing safety data to ensure that the benefits of the vaccine continue to outweigh the known risks. Healthcare professionals are required to report any suspected SAEs to HSA as soon as possible. To facilitate HSA’s safety monitoring, healthcare professionals are required to specify the brand name and batch number of the vaccine when submitting the notification on COVID-19 vaccinations to the National Immunisation Registry, as well as when reporting suspected AEs to HSA. HSA will actively monitor the AEs associated with the vaccine and keep healthcare professionals informed of any significant safety signals associated with COVID-19 vaccines.

* PSAR: Pandemic Special Access Route <https://www.hsa.gov.sg/hsa-psar> Published: 23 Oct 2021

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