This article was originally published in February 2021. It has since been updated by Willow Shah-Neville on April 19, 2023.
The COVID-19 pandemic exposed the weaknesses in our defenses. Vaccine platforms will be powerful tools for reacting faster to future pandemics.
Multiple COVID-19 vaccines became available across the world to tackle the COVID-19 pandemic, signaling a historic moment for vaccine development due to the speed at which they were created. And with scientists believing that such pandemics could occur more often in the 21st century, a lot can be learned from our response to COVID-19.
According to the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services, human activities such as illegal wildlife trade, industrial poultry production, and climate change increase the risk of a zoonotic spillover — the transmission of diseases from animals to humans. With more than five new infectious diseases emerging each year, there’s always the threat of any of them becoming a pandemic. When that happens, vaccine platforms will be crucial for pandemic preparedness.
Platform technology, a term more popular in computer science, refers to a technology that serves as the basis for the development of multiple other processes, applications, and technologies. Extending the definition to pharma, a vaccine platform is any underlying technology — a mechanism, delivery method, or cell line — that can be used to develop multiple vaccines. What are the benefits of investing in platform technologies rather than standalone vaccines?
Speed is vital to slow down the spread
COVID-19 vaccines from Pfizer/BioNTech and Moderna received emergency use approvals from the FDA, and subsequently the EMA, within 11 months of China sharing the genome of the SARS-CoV-2 virus in January 2020. This made them the fastest vaccines ever approved in history.
While it is true that unprecedented amounts of funding were made available – with more than a hundred different vaccines in the pipeline at that time – and that pharma companies benefited from previous research on coronaviruses, there’s more behind the speed of the development of these two vaccines. Both were built using messenger RNA (mRNA) technology, and were the first approved medicines that use this technology.
Other approved COVID-19 vaccines are based on adenoviral vector technology, as well as the more classical protein-based and live-attenuated vaccines. The rapid development of mRNA and adenoviral vector vaccines, when compared to other COVID-19 vaccines, highlights a major benefit of new vaccine platforms: speed.
For instance, Moderna designed its COVID-19 vaccine in just two days. Similarly, the German company BioNTech took just a day to design its vaccine. This is in sharp contrast to conventional vaccines that generally take several months to years to design.
Having multiple vaccine platforms in the race to develop a vaccine also contributes to a faster pandemic response. Surveillance studies routinely identify zoonotic viruses that are likely to spill over to humans. These present ideal pools of candidates to validate emerging vaccine platforms. Doing this would speed up development should any of these viruses actually spill over.
“The idea is that once viruses are selected, vaccines can be produced in different platforms and tested in phase I and phase II trials with some of the produced vaccine being stockpiled,” Florian Krammer, professor at Icahn School of Medicine at Mount Sinai in New York, noted in a scientific paper published in Med.
“A well-prepared infrastructure capable of producing vaccines 3–4 months into the outbreak would have saved many lives and would likely have normalized the situation in many geographic areas by now,” he added. While that could have prevented many deaths, the timeline of COVID-19 vaccines was impressive nonetheless. How did pharma companies manage to design vaccines so quickly? The answer lies in the other major benefit of vaccine platforms: flexibility.
Vaccine platforms are flexible
Both Moderna and BioNTech were working on mRNA vaccines for cancers and infectious diseases such as influenza and Zika before the pandemic. The companies leveraged the platforms developed for these other vaccines to steer their COVID-19 vaccine efforts. They just needed to replace the mRNA with that relevant to the novel coronavirus. Once injected, the cell machinery uses the mRNA instructions to produce the spike protein of the novel coronavirus, which elicits an immune response.
According to a review in Nature Materials, vaccine platforms will be able to adapt to both new strains of circulating viruses and emerging viruses. “The wider array of possibilities for pre-emptive and reactive vaccine design, as well as faster development and manufacturing options, will permanently change our ability to rapidly respond to emerging viruses,” the authors suggest.
Many of these vaccine platforms have shown considerable promise in providing immunity against other viruses such as Zika and Ebola. For instance, the COVID-19 vaccine from Oxford/AstraZeneca, as well as those from Johnson & Johnson and Chinese biotech CanSino, used chimpanzee adenoviral vectors. The Oxford platform has previously been demonstrated to be effective in animal models for Rift Valley Virus (RVF) virus and Zika virus. Moreover, it successfully elicited an immunogenic response for Crimean Congo Haemorrhagic Fever virus, Lassa virus, and Nipah virus, among others.
Other companies are betting on multiple vaccine platforms at once to tackle a diverse range of emerging threats. aVaxziPen, a British biotech startup previously called Enesi Pharma, develops vaccines against multiple infectious diseases, including HPV, chikungunya, Zika, shigella, plague, and anthrax.
“The vaccines we are working with come in all the main formats currently being developed – live attenuated virus, adenoviral vectors, protein subunit, etc.,” David Hipkiss, CEO of aVaxziPen, told me. “So far, we have demonstrated promising results in proof-of-concept studies of all of these formats and are advancing to test them in established preclinical models.”
The startup’s take on mRNA vaccines is different from Moderna and Pfizer/BioNTech, opting for developing solid dose formulations, which can be used to vaccinate people without needles.
“Maintaining the integrity and functionality of the mRNA vaccine construct is the key challenge once it is formulated into a solid form. The first part of our collaboration with Imperial College London was to test if we could do this with a DNA surrogate. This was a success and we intend to apply those learnings to the novel self-amplifying RNA vaccine constructs that Imperial is developing…”Hipkiss added.
Furthermore, aVaxziPen recently announced positive immunogenicity data demonstrating immune equivalence to traditional needle and syringe injection when using a needle-free solid dose formulation. This data, from four in vivo models, reinforces the value of the company’s vaccine platform as a novel way to deliver vaccines for multiple diseases, including tetanus, anthrax, influenza and peanut allergy.
An opportunity for pharma
The SARS outbreak of 2003 was quickly brought under control, leading to the abandonment of vaccines against it. The long-drawn COVID-19 pandemic, on the other hand, led to multiple vaccines and a renewed interest in vaccines among investors. However, most of the funding went to a handful of platforms. Frédéric Garzoni, co-founder and chief scientific officer (CSO) of the U.K. biotech Imophoron, notes how this was a challenge for newer vaccine platforms like those developed by his startup, which engineers proteins with a large particle structure that looks like a virus.
“All available money went to technologies which have been used in human trials before and are proven to be safe. This is understandable but we have to prepare for the future now to prevent future outbreaks and invest in new technologies. Not five or ten but hundreds,” Garzoni said.
Looking to the future, there needs to be sustained funding and efforts towards developing other vaccine platforms. “We need to prepare for future viruses that will come to challenge humanity. We need a portfolio, a toolbox if you like. Some of them will be fast to deploy, some will be slower but will have other advantages, etc. Complementarity will be key,” Garzoni added.