As the World Economic Forum states, vaccination is “arguably the single most life-saving innovation in the history of medicine”.1
For more than 200 years, vaccines have been an important weapon in the fight against deadly and debilitating infectious diseases. Global vaccination programmes have eradicated smallpox, erased polio in most countries, and protected against illnesses such as tuberculosis, diphtheria, tetanus, whooping cough, measles, rubella, rotavirus, hepatitis B, influenza and human papillomavirus (HPV).2,3
In 1980 the world was declared free of smallpox and there was a 99% reduction in polio cases from 1988 to 2000.4 Common childhood diseases such as measles and mumps have also been prevented with great success.
In 2019, it was estimated that immunisation prevents 4-5 million deaths every year and protects millions more from illness and disability.5
Given the current focus and attention on vaccines, we believe it is important for people to understand how vaccine research and development has advanced over time and contributed to the rapid vaccine response during a pandemic.
Discovery and invention – a short history of vaccination
The present day – what are the different types of vaccines?
Today we are fortunate to have several different types of vaccines to prevent different illnesses, including:6
- Inactivated virus vaccines (e.g. for hepatitis A, flu, polio, rabies) in which genetic material has been destroyed to prevent infection, yet immunity can still be generated
- Live-attenuated virus vaccines (e.g. for MMR, rotavirus, smallpox, chickenpox, yellow fever) using a weakened form of the virus to generate immunity
- Subunit, recombinant, polysaccharide, and conjugate vaccines (e.g. for Hib, hepatitis B, HPV, whooping cough, pneumococcal disease, meningococcal disease, shingles) which rely on a range of individual targets, or ‘flags’ to stimulate the immune system
- Inactivated toxin vaccines (e.g. for diphtheria, tetanus) using inactivated substances normally produced by infective organisms to generate immunity
- Viral vector vaccines which use harmless viruses as carriers for specific genetic information to generate an immune response against a specific virus
- Messenger RNA (mRNA) vaccines which carry genetic material into cells in a fatty bubble so that they can make protein to stimulate the immune system
Each vaccine technology works in a slightly different way to prepare the immune system to fight an illness or virus and can also vary in terms of manufacturing ease, dosing or suitability for an ‘outbreak situation’. For example, conventional vaccines (such as live-attenuated) may be hampered by ‘producibility’ in an outbreak situation, and the need for whole pathogen cultivation. Average time from development to clinic for these vaccines can also exceed 10 years.7
Some newer vaccine technologies, such as viral vector vaccines and mRNA vaccines, can be developed quickly on a large scale, making them suited to a pandemic setting and the need for rapid response to prevent global spread.
This versatility, and the fact that vaccine platforms such as viral vectors and mRNA had been studied for many years, can make it possible for scientists to respond quickly and effectively during a pandemic.
What is the future of vaccines?
Scientific innovation continues to drive vaccine research, with a focus on technology, effective delivery techniques and new disease targets. Promising vaccine trials are in progress targeting many infectious diseases, as well as non-infectious conditions such as auto-immune disorders, cancer, allergies and addictions.8
The battle is far from over, with ongoing vaccine research looking at long-term immunity, protection against variants, mixing vaccines and other strategies aiming to improve protection, reduce the burden of illness and ultimately save lives.