‘Dud COVID vaccines are no silver bullet’

Dud COVID vaccines are no silver bullet’: is there a mismatch between public expectations and what vaccine developers define as clinical “success”? If the vaccine is said to “work”, what exactly will it do? How certain is it that it will do this? And what are the implications for public health policy?

It is a common misconception that an approved vaccine will provide “silver bullet” immunity, a scenario based more on a Hollywood film narrative than reality because no COVID vaccine trial protocol defines its “success” as:

• Providing immunity from infection from the SARS-COV-2 virus
• Reducing mortality risk from the COVID-19 disease.
• Providing immunity from COVID-19 disease symptoms

Instead trial “success” is defined as an amelioration of COVID-19 symptoms in 50-60% of volunteers, who are healthy adults likely to be at risk only from a mild or asymptomatic infection and thus not even a population group facing significant mortality risk from COVID-19. These dud COVID vaccines aspire to be buckshot not silver bullets: if they are the answer, what was the question?