In the coming weeks, clinics around the world will need millions of nasopharyngeal swabs for coronavirus testing. But the specialized swabs are complicated to make, and hospitals and regulators worry that current suppliers can't keep up with demand.
But two U.S.-based plastics companies are playing a key role in addressing the shortage.
Researchers at Harvard University, working with health care, researchers and plastics supply chain partners, have designed a new fully injection molded swab that can be manufactured inexpensively and at high volumes.
The team went from design to large-scale manufacturing in just a few weeks.
Nasopharyngeal swabs are the long Q-Tip lookalikes used to collect clinical test sample of nasal secretions from the back of the nose and throat.
The project began just over a month ago, when Beth Israel Deaconess Medical Center (BIDMC) in Boston contacted the Wyss Institute at Harvard University, asking for help to solve the hospital's swab shortage.
"It was an interesting project. Definitely far from what I typically do at Harvard," Richard Novak, senior staff engineer at the Wyss Institute, said in a telephone interview with Plastics News.
"Beth Israel Deaconess reached out to my boss, Dr. Donald Ingber, and they were saying, 'We're reaching out to everybody. We have this huge swab shortage. We can't test enough people. Can you help?'" Novak said.
At the time, there were already two major suppliers of the specialized swabs: Puritan Medical Products in Guilford, Maine, and Copan Diagnostics Inc. in Brescia, Italy. Puritan's swabs are made by Teel Plastics Inc. of Baraboo, Wis. But U.S. Food and Drug Administration officials were concerned that shortages of swabs could limit the health care sector's ability to test people for COVID-19.
The Wyss Institute's staff come from Harvard's Schools of Medicine, Engineering, Arts & Sciences, Design and Education, and they have a close relationship with BIDMC. The institute quickly pulled together a team of experts to develop and test the new swabs.
"We initially started by focusing on 3D printing, just because it's so easy to iterate designs with 3D printing. Obviously there are challenges in terms of the material properties, chemical properties to an extent, structural and also in terms of manufacturing," Novak said.
"But it did enable us to very quickly iterate several designs, and maybe in a week we had some designs that were passed through preclinical testing, which was incredibly fast," he said.
Most nasopharyngeal swabs consist of two pieces: an injection molded handle and an absorptive tip made of a soft material such as cotton, polyester or flocked nylon. Each swab is manufactured in a multistep process, then assembled, sterilized and packaged. The swabs are about 15 centimeters long — long enough to reach where the throat meets the nasal cavity.
The Wyss team's swabs featured a flexible, honey dipper-like design that could be made in one piece.
"We were able to eliminate all of those secondary steps and the supply chain issues that they can create," Novak said.
When large 3D printing companies began to churn out the swabs, Novak's team turned its attention to developing an injection molded version, which he knew would boost production and reduce cost.
That's where Protolabs Inc. of Maple Plain, Minn., came in.