Recent advances in vaccine storage technology could make the storage and distribution of vaccines much simpler, dramatically changing vaccination rates in areas of the globe with limited resources fighting epidemics. The new storage method enables vaccines to be stored in non-refrigerated conditions yet remain safe and effective months later.
Dried Vaccine Sheets
As reported by the National Post, the technique for vaccine storage was pioneered by a chemical engineering team from McMaster University in Hamilton, Ontario, Canada. The engineering team was led by professor Carlos Filipe and Ph.D. graduate Vince Leung. The team tested their technique out on a combination of influenza A and herpes vaccines. The reason these particular vaccines were chosen is that they are extremely sensitive to hear and quite fragile, necessitating storage in just the right conditions.
The McMaster University team took the influenza A and herpes vaccines and mixed them together with a sugar solution, which was then spread out into a thin film and dried. This film was stored at 40°C, or approximately 104°F. After a few months of storage in these conditions, and despite the high temperatures, the vaccines were still just as stable and effective as they were when initially created. The influenza A vaccine was still in prime condition three months after creation, and the herpes vaccine lasted around two months in extreme storage conditions.
When speaking with the National Post, Filipe says he can’t conceive of any reason that the technique couldn’t be applied to many other vaccines, dramatically enhancing their stability and lifetime. According to Filipe, the idea for the project was conceived when Sana Jahanshahi-Anbuhi, Assistant professor qat Concordia University and co-author on the paper, was examining Listerine breath strips at the grocery store. The strips are comprised of a sugary substance referred to as pullulan, which is dried and stretched tight into a thin film. These strips can be stored at room temperature or above without incident for long periods of time. Sugars are capable of shielding certain fragile biological compounds like enzymes from environmental factors that degrade them, and the scientists realized the same process that protects the ingredients in Listerine strips could potentially be applied to proteins in a vaccine.
The pullulan is arrayed in a fashion that prevents molecules of oxygen from penetrating the vaccine molecules, and in addition, helps keep the molecules comprising the vaccine trapped in place. While these molecules would usually break up, decay, and unfold when exposed to heat, the pullulan keeps them bound together. Another type of sugar called trehalose was mixed into the chemical batch, and it served to prevent the particles within the vaccine from desiccating as the mixture was stretched and dried to create the thin film strips.
The dried vaccines were tested in mice, and the rate of success for the vaccinations was extremely high, with all of the mice that had been treated with the preserved H SV-2 TK-vaccine surviving the infection, demonstrating that the vaccines had kept their potency despite long periods of storage in high heat conditions.
A Revolution In Vaccine Storage?
Now that the initial tests have come back so promising, the next step for the team will be to test out the technique on more vaccines, and begin investigating the efficacy and safety of the drive vaccines in humans. According to Filipe, the team has recently applied for funding from the Gates Foundation, and they will be reaching out to other medical partners and firms within the year to discuss bringing the product to market.
Filipe is worried that the inertia of current methods of vaccine storage may prove hard to disrupt. Lots of resources like time, money, and logistical support have been poured into the maintenance of “cold chain” storage systems across the globe, and people are often risk-averse and shy when engaging with potentially disruptive technologies.
Beyond this, there are a number of regulatory checkpoints that the team will have to clear, although the sugars used in the experiment were already approved by the US FDA and by Health Canada. This fact, combined with the fact that the experiment uses pre-existing vaccines with long track records of efficacy and safety, means that the regulatory process should be relatively painless, Felipe thinks.
Yet the potential benefits of this technology are too important to be ignored, as it could radically change how vaccines are stored and distributed. Currently, many existing vaccines are extremely fragile and need to be stored in a climate controlled environment at between 2 to 8°C. Even at the low temperatures, the vaccines typically only maintain their viability for a few days, and any delays that happen during the shipping process could render the vaccines useless. Logistical issues that may delay the arrival of vaccines are real problems, especially in remote, rural, or dangerous parts of the globe.
Filipe envisions a much simpler process where sheets of the dried vaccines are shipped to destinations with less concern over their viability in storage, and then simply dropped into a saline vile where the strip will dissolve and can then be injected.
One of the primary test cases for this technology could be the fight against measles, which has returned to many parts of the world where it was once under control. Madagascar is where some of the worst outbreaks have been witnessed, and according to the World Health Organization around 85,000 people were infected there between October 2018 to March 2019. Other notable outbreaks sites include Ukraine, where approximately 56,000 people were infected during this timeframe, and India where around 90,500 people were infected.
Felipe has visited these countries many times before, and he explains how the dry storage technique could help ensure the safety of the vaccines in these countries.
“The power goes out very frequently. When you take that vaccine from the refrigerator, you really don’t know what happened to that vial before you got there,” Felipe said to National Post. “You can be using the cold chain, but also use this additional level of safety.”
Fighting To Contain Measles Outbreaks
Measles outbreaks in the world have reached such a point of inundation that a group of researchers from Italy recently recommended that compulsory measles vaccinations should be introduced in the United Kingdom, if the situation is going to be controlled. The research team conducted an analysis of current vaccination policies and their data suggests that these policies are insufficient to keep the spread of the measles virus under control.
The Italian team’s study, which was published in the journal BMC Medicine, examined vaccination trends in various countries around the world such as Australia, the UK, and the United States. The analysis concluded by stating that if the percentage of the population susceptible to measles is going to be kept under 7.5% (the level at which the disease is considered eliminated) by the year 2050, swifter and more dramatic actions are needed.
New Scientist reports that the Italian research team found that currently, around 3.7% of UK citizens are susceptible to measles and that this the vulnerable population will increase in size to approximately 5.5% by 2050 unless something is done. However, compulsory vaccination for children entering school augmenting current immunization programs would be enough to maintain stable herd immunity levels throughout the next three decades.
Simon Stevens, of England’s national health society, explains that “Vaccine rejection is a serious and growing public health time-bomb.” His statement comes after an analysis of measles cases in England throughout 2018 and found that there were 966 cases in the country, which was up considerably from the 259 cases in 2017. Stevens goes on to say that social media firms should crackdown on the dissemination of misinformation regarding vaccinations, and adopt a zero-tolerance approach.
Changing Minds On Vaccination
As research into vaccines themselves continues, so does research into the psychology of anti-vaccine proponents and those who exhibit “vaccine hesitancy”. A recent study examined strategies that may encourage those who view vaccines negatively to become pro-vaccine.
As reported by Business Insider, a study conducted by Brian Poole and Jamie Jensen from BYU found that exposing people to those who suffer from vaccine-preventable illnesses tends to make them more pro-vaccine. Poole and other BYU researchers surveyed around 600 people who had various opinions on vaccines. There were 19 individuals who professed to have negative feelings about vaccines that were not studying vaccinations as part of their college curriculum. After interviewing someone who had suffered from a vaccine-preventable illness, 13 of those people shifted their position on vaccines.
It is important to keep in mind that the number of people who changed their minds on vaccines wasn’t a massive number, and that the study took place amongst a fairly homogenous “WEIRD” cohort of people. Nonetheless, the study does seem to fall in line with other research suggesting that human-based narratives tend to be very effective in shaping the way people think about diseases and vaccines.