The Expert Committee on COVID-19 Vaccination (EC19V) recommended that the messenger RNA-based (“mRNA”) COVID-19 vaccines – Pfizer-BioNTech and Moderna vaccines – be used in Singapore following the authorisation of both vaccines by the Health Science Authority (HSA) under the Pandemic Special Access Route (PSAR). We have noted social media messages asserting that the mRNA COVID-19 vaccines are ineffective against Variant of Concerns (VOCs) and that inactivated virus COVID-19 vaccines would provide superior protection. Our assessment, based on a continual review of data and evidence, remains that the PSAR-authorised mRNA vaccines are safe and highly effective, and continue to show protection against the VOCs. The inactivated virus COVID-19 vaccines have variable protection and there is currently no evidence to suggest that inactivated virus vaccines demonstrate higher vaccine efficacy against VOCs than the mRNA vaccines.
PSAR-Authorised mRNA Vaccines Are Safe and Effective Against COVID-19
2 The Pfizer-BioNTech and Moderna mRNA vaccines have been consistently shown to be highly efficacious, at around 90%, especially in protecting against severe COVID-19 disease and hospitalisation. This was first demonstrated in the pivotal Phase 3 clinical trials, and further supported with the data from actual roll-outs in the real-world, including in the United States (US), the United Kingdom (UK) and Israel. This includes protection against key VOCs such as the alpha and beta variants, which were the predominant strains circulating in these countries.
3 Despite concerns over the delta variant, emerging data shows that the mRNA vaccines continue to be effective. A study in the UK demonstrated that two doses of the Pfizer-BioNTech mRNA vaccine confer about 88% protection against symptomatic COVID-19 even with the delta variant. While further studies are required before a definitive conclusion can be made, the available data globally indicates that substantial protection is preserved.
4 Protection conferred by any vaccine is not 100%, and with the emergence and spread of new variants due to mutations, vaccine-breakthrough infections can occur. The detection of asymptomatic to mild infections locally with the delta variant does not indicate a lack of protection. The finding that the infections have been asymptomatic to mild in symptoms is in keeping with the global evidence that the mRNA vaccines have a high level of protection against symptomatic and severe disease.
5 The Pfizer-BioNTech and Moderna vaccines have been approved by multiple reputable international regulatory bodies. The manufacturers have publicly released their detailed study protocols and openly published their findings to be scrutinised by the scientific community after peer review. The detailed assessments of their vaccines by regulatory bodies such as the US Food and Drug Administration and the UK Medicines & Healthcare Products Regulatory Agency have also been publicly published.
6 In sum, the PSAR-authorised mRNA vaccines have reliable scientific evidence that they are safe and effective, and the EC19V continues to strongly recommend that medically eligible persons should be vaccinated with them.
COVID-19 Inactivated Virus Vaccines
7 The Sinovac vaccine has yet to meet the requirements for a PSAR authorisation by HSA as additional safety and quality data required to meet the standards of the PSAR evaluation are still pending. The Sinovac vaccine has also shown variable protection across multiple studies carried out internationally. The most complete analysis of the vaccine showed a vaccine efficacy of 51% on per-protocol analysis. The protection of Sinovac against newer variants such as the delta variant and under real-world conditions remains unknown.
8 Sinovac has been qualified by WHO under its Emergency Use Listing (EUL) Procedure for use only in persons aged 18 years and above. WHO does not recommend it for use in persons below age 18 years. As such, it is currently not an option for children and adolescents globally nor in Singapore under the Special Access Route (SAR).
9 It is critical that medical professionals do not spread unsubstantiated and unscientific information. The public has a right to expect medical professionals to give advice based on fact and not on unproven assertions. The public should rely on reputable sources of scientific and medical information, and verify opinions shared by others against these. The PSAR-authorised mRNA vaccines are safe and effective, and the EC19V recommends that medically eligible persons in Singapore should be vaccinated with them.
EXPERT COMMITTEE ON COVID-19 VACCINATION
7 JUNE 2021