Modelling self spreading vaccines in a reasonable worst case influenza pandemic in the UK

Abstract

Self spreading vaccine are genetically engineered organisms that confer immunity to disease and can spread from person to person in the same way diseases do. Self spreading vaccines have been used in recent years to inoculate animal populations where large scale direct vaccination is not feasible. In a hypothetical pandemic of a new unknown pathogen the difficulty of quickly producing and administering strain specific vaccine in large quantities is the major limiting factor in its use in pandemic defense. Self spreading vaccines can have an impact exponentially greater than the numbers of people directly receiving them by spreading from person to person. They potentially offer an opportunity for effective intervention early in a pandemic with comparatively little vaccine. We discuss the likely properties of any hypothetical pandemic specific self spreading vaccine devised to protect against highly lethal influenza strains. We have created a simple compartment based model for such a vaccine and have used it to produce conservative estimates of the impact such a vaccine would have deployed against a reasonable worst case influenza pandemic in the UK along with a basic sensitivity analysis for some key parameters. In this hypothetical exercise we hope to demonstrate the utility and potency of self spreading vaccines in combating pandemics and safeguarding lives and discuss the wider implications and issues with their adoption.