ABU DHABI—Getting vaccines from lab to patient can be costly and complicated. The temperature needs to be kept constant throughout the supply chain—if at any point the vaccine is left out of the refrigerator then it could denature, becoming useless.
Those requirements make it a logistical nightmare to deliver life-saving inoculations to war zones or remote areas where the “cold chain” cannot be guaranteed because of unreliable power supplies.
Marieh al-Handawi, a chemist at New York University–Abu Dhabi, wants to change this. “At the moment, failure at any point in the cold chain becomes a total failure. We want to eliminate that prospect.”
She is trying to create a thermostable vaccine that could be shipped at room temperature without losing its potency or causing any danger to the patient.
Medical experts say research like this could one day save lives in the Middle East’s trouble spots and elsewhere around the globe.
Patients in “Yemen and Syria can be really hard to reach,” says Tanja Ducomble, a vaccine coordinator at Médecins Sans Frontières, a humanitarian group also known as Doctors Without Borders. “It would be so much easier to get vaccination supplies to those countries if we didn’t have to think about the cold chain.”
In Syria alone, tens of thousands of children haven’t been vaccinated against preventable diseases such as measles, rubella and tetanus, according to Médecins Sans Frontières—in part because the situation on the ground simply doesn’t allow for the correct storage temperatures to be maintained.
Ducomble says her organization managed to get 15,000 doses of an expensive pneumonia vaccine into Syria last year, only for them to be wasted because the generator at a cold house broke. “We couldn’t get it fixed in time. These situations are frequent in conflict areas,” she says.
A Protective Shield
Back in Abu Dhabi, al-Handawi has encased a plant virus inside crystals made from synthetic calcite and calcium carbonate—both cheaply available ingredients. The crystals create an armor that protects the virus against the harmful effects of high temperatures.
“You can think of it like a shield,” she says. “The next step is then to figure out how to administer the vaccine once it reaches the recipient.”
The protective crystals readily dissolve when exposed to acidity and al-Handawi now wants to see if stomach acids would do the job, in which case the patient could simply eat the vaccine without any need for needles or specific training of healthcare workers—qualities that would be added bonuses.
She also wants to progress from experimenting with plant viruses, which she used to prove the concept, and move on to testing with viruses that cause human diseases.
This will require the United Arab Emirate’s government approval, for which she has already applied, and extra funds. “You wouldn’t think so, but buying viruses is actually very expensive,” she says.
Other researchers around the world are working on thermostable vaccines. Three are already approved for use by the World Health Organization. One inoculates against meningitis and can last three days without refrigeration. Another prevents human papillomavirus and lasts four days without refrigeration, and the third is a cholera vaccine, which can last 14 days.
But each pathogen is different and no one-size-fits-all solution exists to create thermostable vaccines. For example, al-Handawi’s method is unlikely to work for bacterial diseases because their cells are too big. She also thinks the shape of the virus is important; while her technique was successful with a sphere-shaped virus, it failed with a rod-shaped virus.
Al-Handawi and her team need time to figure out which viruses affecting humans and which relevant proteins needed in vaccines can be encased in protective crystals, but she says they’ll start by targeting diseases that most populations are routinely vaccinated against, such as polio.
While thermostable vaccines increase the possibility of reaching remote and dangerous parts of the globe, the technology will still be useful for wealthier and more stable regions, says al-Handawi.
“Even rich countries like the U.A.E can benefit,” she says. “They will still enjoy saving money on the cold chain process.”
Other experts agree.
Bruce Lee, an associate professor of international health at Johns Hopkins University, conducted a study in 2017 that determined the potential economic value of thermostable vaccines at different price points. “We found that doubling and tripling the thermostable vaccine price still resulted in cost savings,” he says.
There’s no reason why vaccines produced with al-Handawi’s method should be more expensive than traditional ones because the raw materials are cheap. Coupled with the cold chain cost savings, she hopes her research will mean vaccine delivery becomes significantly cheaper. That could result in broader protection against disease for the world’s poor living in hard-to-reach places, and better prices for those who can already afford immunization.