Protecting the health of the global population will need a new generation of vaccines that are effective, affordable and accessible to everyone who needs them - even in the midst of a disease outbreak. Vaccine research has come a long way since Edward Jenner and his cows, but there are still many challenges to be overcome.
Vaccines are all based on antigens: molecules derived from pathogens such as bacteria and viruses. They create protection by ‘training’ the immune system to recognise and respond to the corresponding disease-causing versions.
Identifying antigens with the potential to make an effective vaccine therefore requires deep knowledge of infections and immunity. But we do not fully understand how the immune system responds to different diseases - particularly to complex pathogens like malaria - or how it varies in genetically diverse populations around the world. Even when scientists find a vaccine candidate that elicits an immune response in laboratory tests, there is no guarantee that the vaccine will be safe and effective in human populations.
Human infection challenge (HIC) studies - in which a small number of healthy volunteers are vaccinated and deliberately infected with pathogens under tightly controlled conditions - have a vital role to play in revealing how the immune system responds to disease and the effectiveness of novel vaccines.
Changing the incentives
Every promising new vaccine has to be tested in large clinical trials costing millions of pounds. Even at this stage there is a chance that the vaccine will not be effective or will cause unacceptable side effects, which makes vaccine development commercially risky. As a result, many promising vaccine candidates get stuck in the ‘death valley’ between early stage testing and large-scale trials.
In the vaccine community, we don’t look for barriers. We look for ways of getting things done - Dr Stephen Lockhart, Pfizer
This is especially true when it comes to developing vaccines against diseases that are endemic in low-income countries with restricted healthcare budgets. The global health community could pull policy levers to shift the financial British Society for Immunology | Celebrate Vaccines incentives for pharmaceutical companies and their shareholders, encouraging investment and innovation in vaccine development.
Delivering vaccines to everyone who needs them
While it is essential to push forward with the development of new vaccines, we should not forget the ones we already have. Global infant vaccination rates have been stuck at around 85% for the past ten years with factors such as war, unstable political situations and poverty limiting healthcare access for the remaining 15% of children.
These genetic technologies should be put to use in the next generation of vaccines, making them cheaper and more accessible to people wherever they need it - Professor Beate Kampmann, IMPRINT Network
Bringing immunisation to low-income settings raises many challenges: where are the people who will benefit the most, and which diseases do they need protection from? Can vaccines be manufactured in a cost-effective way, then shipped to the communities that need them without the need for refrigeration? And are there enough trained healthcare workers to deliver them when they arrive? Solving these problems will be a crucial part of improving global public health.
The future is now
Exciting things are coming in the world of vaccine research. Aside from COVID-19, which is currently dominating international research efforts, one of the next vaccines that is expected to come to market soon is for respiratory syncytial virus (RSV) - a development that could save the lives of tens of thousands children in the poorest parts of the world. Further into the future, there is hope for universal flu and broadspectrum bacterial vaccines that work against current and future strains of these fast-evolving microbes.
One major hurdle is the speed at which vaccines make the journey from the lab to the clinic. This is particularly pressing in fast-spreading outbreak situations caused by emerging pathogens previously unknown to science. Novel technology platforms are creating the next generation of DNA or RNA vaccines based on the genetic code of the infectious agent. Unlike conventional immunisations, these vaccines can be put into production quickly and easily, potentially even in low-resource local settings.
However, all these innovations require investment. Since 2017, there has been a decrease in grants awarded each year by all top 10 funders of vaccine research and development in the UK (see page 8). If this continues, we are likely to lose our momentum and our ability to capitalise on the UK’s position at the forefront on immunity research.
Building on knowledge to accelerate progress
Peter Openshaw is Professor of Experimental Medicine at Imperial College London, and was president of the British Society for Immunology for five years. His research focuses on vaccines against flu and RSV.
“We can’t be complacent. Every infectious disease is a many-headed hydra; you cut one off and three more pop up. We are trying to counter these microbial threats, but they constantly change and re-appear. Whenever you think you can sit back and take a breath, another one comes.
“There are still many unsolved questions and diseases for which we need new or better vaccines. But we don’t start any vaccine development from ground zero. All the work that has been supported by organisations like the Wellcome Trust and the British Society for Immunology over the past many decades has laid the foundations for developing new vaccines when we need them.
“Making a vaccine from scratch can take 20 years or more but building on prior knowledge can accelerate the process, enabling us to get people immunised quickly when we need it. That was certainly the case for the recent Ebola vaccine and it is the same for the novel COVID-19 vaccines that are already entering clinical trials.”