At 5 billion, PATH’s life-saving labels make vaccines more effective

Health worker and vaccine vials with the heat-sensitive VVM.
Health worker and vaccine vials with the heat-sensitive VVM.
WHO

Sometimes, a simple technical fix – or techno-fix, as the critics like to say – is exactly what’s needed. It’s getting people, organizations and industry to accept the change that can be the biggest complication.

Seattle-based PATH recently celebrated a techno-fix milestone – reaching the 5 billion mark for the number of vaccine vials distributed worldwide bearing a life-saving, heat-sensitive label.

First developed by the food industry to make sure edibles remained properly refrigerated during transport, when used for immunizations this label is known as the vaccine vial monitor, aka VVM.

Most vaccines need to be kept at a precise temperature under refrigeration; VVMs tell health workers operating in harsh conditions and traveling to remote locations if the vaccines remain protected and viable by the time they are administered.

All polio vaccines today have VVMs, as do all vaccines used by UNICEF or pre-qualified by the World Health Organization, but even after 25 years they are still not uniformly in use in the private sector, in the developed world or by PAHO (Pan American Health Organization).

A chart showing the different visual readings given by VVMs to track heat exposure and damage to vaccines.
A chart showing the different visual readings given by VVMs to track heat exposure and damage to vaccines.

“We faced great reluctance by the vaccine manufacturers at first,” recalled Debra Kristensen, group leader for vaccine and pharmaceutical technologies at PATH.

Debra Kristensen
Debra Kristensen
PATH

Kristensen is one of the old-timers (sorry about that Deb!) at PATH, having started there back in the days when it was still a small, fairly unknown outfit in Seattle. Since the late 1970s, when Bill Gates was a teenager and the organization was still known as the Program for Appropriate Technology in Health, PATH has been inventing some pretty cool humanitarian gizmos. (Last week, they announced a new use, an injectable contraceptive, for another of their early inventions, the single-use syringe.)

But what may today sound like an obvious solution to a problem – vaccine spoilage – actually took decades to become more widely adopted.

PATH used to be a fairly confusing organization for many in the aid and development world, in part because the Seattle gang of health innovators often sought to work with industry to find profitable solutions for problems that, at the time, were largely viewed as caused by the failure of industry and the marketplace to serve the needs of the poor.

The PATH approach is fairly routine today – sometimes dubbed a public-private partnership or maybe ‘social enterprise’ – but back then such an approach just created suspicion on all sides. Many within the traditional aid and international health community saw PATH as if it was simply operating as industry in disguise – while industry sometimes viewed them as meddling do-gooders.

“This was during a time when donors and industry were abandoning vaccination,” Kristensen said. In the late 1980s and into the early 1990s, child vaccination rates (which had been significantly increased by UNICEF under the leadership of Jim Grant) were beginning to decline globally due to donor fatigue with funding the same old, never-ending immunizations and the lack of much profit margin for the drug industry.

“And so here we were, trying to impose a new demand and an additional step in the manufacturing and delivery process,” Kristensen said. The drug industry argued it would add costs and undermine what little commercial interest they had in vaccines, she said.

But Kristensen, PATH and colleagues at the WHO (who originally came up with the idea) persevered, recognizing that without some method for ensuring vaccine viability many of the world’s biggest global health efforts dependent upon vaccinations – such as the campaign to eradicate polio, or the broader goal of reducing child mortality – were unlikely to succeed.

Bouncing off the food industry’s approach, PATH technicians spent years modifying and testing the label to adapt it for vaccine transport in poor conditions. Keeping vaccines properly refrigerated from the manufacturer to the shippers to cooler-toting health workers in poor countries on horseback or bicycle is generally known as the immunization ‘cold chain.’

It would have been nice if the food-preserving technology could have simply been adapted for use in health care, but it took nearly a decade before VVMs were commercially available, starting in 1996.

“It was a lot messier and more difficult than many anticipated,” Kristensen said.

After all was said and done, PATH partnered with a company, Temptime, to make the VVMs – adding only a few pennies to the cost of a polio vaccine. Billions of vaccines have been administered with VVMs, saving an estimated $14 million annually by preserving vaccines that otherwise would have been discarded. Making sure kids, children mostly, get viable vaccines also saves lives, of course.

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About Author

Tom Paulson

Tom Paulson is founder and lead journalist at Humanosphere. Prior to operating this online news site, he reported on science,  medicine, health policy, aid and development for the Seattle Post-Intelligencer. Contact him at tom[at]humanosphere.org or follow him on Twitter @tompaulson.

  • Todd McClafferty

    The project team I’ve been a part of has long pushed for and advocated use of VVMs by ours and other programs. The notion that it “adds a step” is specious, at least it is once the correct VVM had been identified, sourced, and qualified on production lines (and SOPs/guidance docs are brought up to date). That may sound like a lot—and it’s not nothing—but it’s all minor compared to the process of vaccine manufacturing. Distribution is the third hurdle in maintaining cold-chain (after production and storage), and VVMs truly shine during the logistics phases. They provide all parties peace of mind and are simpler, cheaper, and less prone to mishandling than a TempTale-style electronic device. The cost of committing to VVMs is negligible compared to the loss of viable product, particularly during clinical research. Customs delays can also lead to a broken, or at least questionable, cold-chain; QA/QC will invariably determine that the shipment is non-viable.

    My question/concern is whether any VVM can indicate a low-temperature excursion. Consider a typical recombinant vaccine with shipping/storage conditions of 2° to 8°C (but with limited expanded stability data to support high-temperature excursions). When these suspensions become cold enough to form ice crystals, dogma (if not data) holds that the proteins are destroyed. Low temperature excursions are the source (literally) of nightmares for project managers. Another technical consideration is that VVMs do not mirror the kinetics of a vaccine.