We will learn about the landscape of pathogens that have the potential to cause pandemics in humans. These are the “emerging” pathogens non-human pathogens that have the ability to infect humans, and either already have, or acquire the ability to, transmit among humans. We will use influenza virus as a case study for “re-emerging” viruses, viruses that have already infected humans but have the ability to do so time and again - in two different ways. First, in the form of influenza pandemics, four of which have occurred in the last 100 years, in which an influenza virus in another species somehow gets into humans and starts to transmit among humans. Second, in the form of seasonal influenza viruses that transmit from human to human, with no other animal species involved, and cause world-wide epidemics of influenza that infect about 10% of the world’s population each year.
Most of the morbidity and mortality of infectious diseases worldwide is caused by antigenically variable viruses that can evolve to escape immunity, induced by prior infection vaccination, and re-infect us again - this is the mechanism by which, for example, seasonal influenza viruses infect us time and again during our lifetimes. We will learn about how such “antigenically variable” viruses evolve and how basic research scientists and public-health scientist team up to track the global evolution of influenza viruses and how the strains of influenza virus which go in the vaccine are chosen each year. The influenza virus is the most complex currently licenses virus, as there is the option to change the strains of the virus that are in the vaccine each year.
We will then learn about the latest research in trying to predict the evolution of such viruses, and how this research can be used to generate vaccines of the future that predict the evolution and thus have the chance to “get ahead of the game” and protect us better.
Finally we will talk about the ethics of doing research on infectious diseases, about some of the dilemmas, challenges, and pleasures that scientists have when doing science on which people’s health, and sometimes lives, may depend.
