Vaccines and beyond
If you want a deeper understanding of the COVID-19 vaccination landscape, Dr Marc Evans is here to help. This week on Horizons we’re launching part one of his two-part presentation, an in-depth survey of the various vaccination approaches and how each of them performs against new variants.
Dr Marc Evans’ research passions are real-world evidence, epidemiology and pharmacoepidemiology – making him perhaps the ideal guide on a tour of the current COVID-19 vaccine landscape. As he points out at the start of his first presentation, quoting respected Yale vaccine researcher Saad Omer: “this is an evolving science; it’s like watching sausages being made in front of the world’s eyes.”
The focus of this first installment is on the various vaccines that have already been produced - at remarkable speed and with a remarkable degree of efficacy - from this real-time sausage-making process. First, Marc examines the different approaches taken to induce an immune response against the SARS-CoV-2 virus – the various potential vaccine platforms.
“Typically we could use a whole pathogen, the live attenuated or inactivated approach, to induce an immune response,” says Marc. “We can use nucleic acid-based vaccines, either DNA or RNA based. We can generate antibodies against the toxoid antigen produced as a result of SARS-CoV-2 penetrating cells and that inflammatory response that is consequent on the toxoid. We can look at subunit recombinant protein-based antigens, targeting specific units - subunits - within the SARS-CoV-2 viral membrane. We can look at viral vector-based vaccines. We can generate vaccines against various polysaccharides within the membrane of the SARS-CoV-2 viral particle. Or we can look at polysaccharide conjugate-based vaccine platforms. Now, where we’re going at the moment is very much along the route of the messenger RNA (or mRNA) vaccines and there’s a lot of excitement and interest in this as a potential therapeutic modality.”
As Marc attests, this has been largely a success story - thus far. But there’s still a long way to go. “We have already seen a lot of data around the differing vaccine effects in terms of efficacy against severe COVID-19 and we can be fairly reassured that the various vaccine candidates actually provide fairly good protection against severe illness. But what we really want to now is, what might happen in the future with respect to these vaccines in terms of all the emerging variants.”
In next week’s film, Marc will be examining the epidemiology and future directions of the COVID-19 pandemic, sharing some modeling insights as to what we might expect to see in terms of implementation and rollout of vaccination across the world.