One of the logistical challenges with COVID-19 vaccines is the fact that many of the vaccines in development—including from Pfizer and Moderna—require two doses. If it’s hard to deliver a vaccine to nearly the entire global population once, it’s even harder to do it twice. The same problems exist for many childhood vaccines, and that’s one reason that children in the developing world are often undervaccinated.
An MIT spinoff called Particles for Humanity is working on a solution: new technology that makes it possible to deliver multiple doses in a single shot. The startup recently received a $5 million grant from the Bill and Melinda Gates Foundation to evaluate the technology, which was developed at an MIT lab and has been tested successfully in animals.
It’s fairly common for vaccines to require multiple doses. “If you get a strong boost to the immune system that lasts for a long time with just one injection, one injection will be enough, but in some vaccines that over time that immune system stimulation declines, and then you need another injection to boost it,” says Sherri Oberg, Particles for Humanity CEO and cofounder. That’s particularly a problem for people living in remote areas. “In some parts of the world, people have to walk for days to get their vaccines,” she says. “They have to take time off from work. If you don’t get all the shots, then these vaccines don’t work as well as they should. And that makes you vulnerable to all kinds of disease.”
The new technology works like traditional drug delivery, but with the addition of tiny time-release capsules filled with antigens, the part of the vaccine that stimulates the immune system so that it can later respond to a virus. “We’ve engineered these particles or time-release capsules to mimic the timing of whatever the approved dosing regimen is for the vaccine,” she says. For a shingles vaccine, for example, which requires a second dose two months later, the first injection includes tiny particles that will release the next dose inside the body at the two-month mark.
The company is starting first with the rabies vaccine, which requires five injections in a six-week period. Once that’s proven, they’ll move on to other vaccines, such as HPV and polio. As an early-stage company, Particles faces several steps before it can use this technology, including more testing and work to plan mass production. It won’t be ready in time for the first round of COVID-19 shots. But Oberg says that the pandemic illustrates why this type of technology is needed.
“I think what’s happening right now is shining a bright light on the challenges that happen in a pandemic where you’re trying to vaccinate billions of people as quickly as possible,” she says. “And that’s a logistical challenge that nobody’s ever seen, in my lifetime, anyway. It’s going to be a big logistical challenge even if it was only a single vaccine, but when you have to do multiple injections, that just adds extra complexity. These are the types of problems that we’d like to solve.”