While COVID-19 has put a spotlight on the biopharma industry, the light hit squarely on vaccines this past year. 2021 saw the speedy arrival of not one but three COVID-19 vaccines. It wasn’t just a huge step towards potentially ending the pandemic. It was important for vaccine development in general.
Because in the race to develop COVID-19 vaccines, researchers were able to explore and develop vaccine technologies in a historically unprecedented fashion.
One vaccine technology getting plenty of attention these days is vaccine adjuvants. While often misunderstood, adjuvants are used in many vaccines and have been in use for nearly 100 years. They are the unsung heroes of vaccines – and their use is on the rise.
What are vaccine adjuvants?
Vaccine adjuvants are compounds added to specific types of vaccine formulations. Not to be confused with excipients which are non-active ingredients, adjuvants significantly enhance the immune response. The word adjuvant means to ‘help’ or ‘aid,’ because they were initially used to improve vaccines with poor immunogenic potential.
The history of vaccine adjuvants
Adjuvants have been around since the 1930s when aluminum salts were found to strengthen the body’s immune response to diphtheria and tetanus vaccines. For nearly seventy years, alum was the only adjuvant used in vaccines, as researchers felt it was sufficient to increase antibody response. They were hesitant to introduce more variables into what was already considered complex chemistry for the time.
Adjuvant research hasn’t always been a priority. Often, researchers would ignore adjuvants since not all vaccines need them. For example, live-attenuated vaccines like the chickenpox vaccine contain a version of the virus that initiates an innate immunity. Similarly, certain inactivated whole-pathogen vaccines contain components that act as adjuvants. Because there wasn’t a universal need, adjuvants were relegated to the backburner for a long time.
The second approved adjuvant wasn’t introduced until the late 1990s, in which a hepatitis vaccine used a virosome adjuvant system. Shortly after, an oil-in-immersion compound known as MF59 was approved for use in vaccinations against the influenza virus.
Today, seven approved adjuvants are currently components of more than 30 vaccines licensed across the globe. In addition to the approved adjuvanted vaccines, many other adjuvants have been tested in humans but are not currently on the market.
This growing list of adjuvants is indicative of a paradigm shift in vaccine development. Part of this shift has come from a better understanding of innate immunity and how the immune system senses microbes through pattern recognition receptors. This discovery has opened a door for novel adjuvants that target pattern recognition receptors (PRRs) and impact an adaptive immune response.
LGM Pharma is a provider of vaccine adjuvants for our bio/pharma customers. We are seeing more demand for vaccine adjuvants like CpG ODN 7909 and CpG ODN 1018. The latter is being evaluated in clinical trials as a potential vaccine adjuvant for COVID-19 vaccines. These novel adjuvants are TLR (Toll-like receptor) agonists, which trigger an innate human immune response – unlike traditional adjuvants, which increase antibody response.
Modern adjuvants can tackle modern problems
While traditional adjuvants have served their purpose, they fall short when addressing specific populations and pathogens. With an adjuvant like alum, the immune response isn’t targeted. In today’s world, specific populations like elderly patients, immunocompromised patients, chronic disease sufferers, and infants need a more targeted approach. Adjuvants can help improve the immune response in these populations.
Novel adjuvants can help improve efficacy in situations where scientists have run up against challenges or when pathogens have proven resilient. For example, an unadjuvanted influenza vaccine led to lowered immunogenicity versus an influenza vaccine with adjuvants.In addition, novel adjuvants have made improvements in situations where alum could only achieve a limited amount, such as HPV.
The challenge with novel adjuvants is that there remains much more to learn. Luckily, the industry’s renewed focus on vaccines and vaccine technology puts more focus on adjuvants. The more we can understand them, the better we can protect vulnerable populations and address unmet vaccine needs.
As a trusted adjuvant supplier, we are seeing more projects with novel adjuvants – and we’re excited that researchers recognize the need for further exploration of adjuvanted vaccines.
The biopharma industry has only just scratched the surface regarding vaccine adjuvant technology, and we can’t wait to see what the future holds for vaccines with novel adjuvants.
Are you researching new vaccine chemistries? Contact us to discuss your vaccine adjuvant sourcing needs.