A CSIRO study has found MOFs (metal organic frameworks) to be a possible solution to address the challenge of transporting temperature-dependent vaccines.
According to the study, for vaccines to work with the maximum potency, they must be stored in specific conditions to avoid degradation across manufacturing, distribution, storage as well as administration; also known as the cold chain logistics.
The World Health Organisation had estimated that at least 50 percent of vaccines are wasted globally each year due to a lack of facilities and temperature control.
Most vaccines need to be stored at a temperature between 2 to 8 degrees Celsius, however many live vaccines can be frozen and kept at temperatures between -15 to -50 degrees.
The requirement of cold-chain logistics were one challenge to Australia’s COVID-19 immunisation rollout in 2021. For instance, both Pfizer and Moderna COVID-19 vaccines require long-term storage at -70 degrees, making distribution of the vaccines difficult and expensive.
CSIRO researchers have found a possible solution to the problem by encapsulating live virus vaccines with a dissolvable crystalline material called MOFs, which acts as a scaffold, protecting vaccine molecules from heat stress and eliminating the necessity for refrigeration.
Prior to administration, a solution will then be added to dissolve the MOF, exposing the vaccine particles.
There are currently two approaches to address temperature stress for non-refrigerated vaccines; either engineer the vaccine to increase its stability or add stabilising agents to the solution.
Whilst engineering vaccines is difficult and complex, there have been several studies exploring the potential of stabilising agents. A Canadian study in 2019 has shown that dried herpes and Influenza A virus vaccines have been successfully stored at 40 degrees for up to two and three months respectively in low-cost sugar films. Additionally, a 2016 study from the UK showed that adenoviral vaccines can be stable for up to 10 days at 37 degrees by adding polyethylene glycol, nanoparticle gold, and table sugar to the solution.
The CSIRO study conducted found MOFs protected the integrity of live viral vaccines for up to 12 weeks with decreasing effectiveness as time increases at an overall temperature of 37 degrees Celsius. Without refrigeration, the vaccine would normally last only a few days.
The research focused on two different types of live viruses; a Newcastle Disease vaccine designed to protect poultry and a strain of the Influenza A vaccine.
The CSIRO advertises itself as having the world’s “first technology to manufacture industrial scale quantities” of MOFs as a commercial outlet for the organisation on its website.
The paper’s author, CSIRO researcher Ruhani Singh, said the technique was cost-effective and scalable.
“This world-first approach of stabilising a vaccine with MOFs is simple, rapid, and scalable because it takes one step.”
CSIRO scientist and immunologist Daniel Layton said the breakthrough science would now focus on proving the approach for other animal and human vaccines, including mRNA COVID-19 vaccines, with the team looking to partner with animal and human health companies to commercialise their work.
“Vaccination is undoubtedly one of the most effective medical interventions, saving millions of lives each year, however delivering vaccines, particularly to developing countries, is challenging because they often lack the cold storage supply chains required to keep the vaccine viable,” Layton said
“This breakthrough has the potential to enable more affordable and equitable access to vaccines across the world.”