Authors (including presenting author) :
CHAN TK
Affiliation :
Nuclear Medicine Unit, Queen Elizabeth Hospital
Introduction :
During the COVID-19 pandemic, vaccination can protect individuals, reduce overall infection and ultimately achieve herd immunity. A vaccination strategy with highest possible odd of producing the desired outcome should be adopted.
Objectives :
Using Hong Kong and Singapore as examples, this article normatively derives a proper approach to vaccine selection for populational vaccination.
Methodology :
Hong Kong has been providing two vaccines of different technologies and efficacies since the beginning of the vaccination campaign, whereas Singapore recommends two vaccines of same technology and similarly high efficacy. The following issues are discussed: Which vaccine selection strategy better serves social interest of reducing overall infection and achieving herd immunity in shortest possible time? 2. Which better serves the individual medical interests of the vaccine recipients? 3. Should we compare vaccines given limited research data? 4. How should we strategise selection of vaccines?
Result & Outcome :
Findings:
Preferentially using vaccines of higher efficacy more effectively reduces overall infection, achieves herd immunity in a shorter period of time and better prepares the community for the potentially more virulent variants. A more efficacious vaccine in general offers better individual protection against symptomatic infection. There may be even more significant health implications for participants older than 60 years old, having other morbidities or obesity. Policymakers should act on indirect comparison of different vaccines using best available data. To achieve greater societal good, there is a strong imperative to provide vaccines with best efficacy-safety profiles.
Conclusions:
The guiding principle is to procure vaccines of best possible efficacy-safety profiles. For supply or financial reasons, any immediately available approved vaccines may be first utilised for vaccine rollout. A prioritising scheme may be devised to provide high-risk groups with vaccines of better efficacy-safety profiles. Less efficacious traditional vaccines may also be provided as a backup alternative for those medically unfit to receive mRNA vaccines or with worry over long-term safety of mRNA vaccines. In parallel, on-going efforts should be made to obtain as many vaccines of best possible efficacy-safety profiles as possible.
