How vaccine vial monitors help protect children against disease

For 30 years, a simple heat-sensitive label has given health workers immediate proof that a vaccine is effective.

_{By Jjumba Martin, Anita Reza Zein | 9 Nov 2026}

Motorcyclist transports supplies along a rural dirt road surrounded by green fields.

To stay safe and effective, vaccines must be kept at the right temperature range from the moment they are made until they reach the people who need it. But if a vaccine is damaged by heat, there’s no way to tell.

Health worker carries vaccine carriers towards a building marked Vaccines and Medicines Store.

In remote health centres, maintaining that cold chain is a constant struggle against extreme heat and unreliable power grids. When the electricity fails, health workers face a critical question: is the vaccine still ok to use?

Two health workers inspect supplies beside an open blue vaccine refrigerator at a health facility.

Close-up of orange vaccine vial caps showing heat-sensitive vaccine vial monitor indicators.

Vaccine vial monitors eliminate that uncertainty. They use a heat-sensitive chemical that irreversibly darkens over time as temperatures rise, meaning health workers can see immediately if the vaccine has lost its efficacy.

Health worker in a headscarf examines vaccine supplies beside open cold boxes at a clinic in Indonesia.

"In many clinics, if the power goes out people assume all the medicine is ruined. The vaccine vial monitor allows us to see whether a vaccine is still safe or damaged by heat... Without it, we might throw away an entire supply unnecessarily."

Yulianti Rohimah, Health Worker, Puskesmas Rancabali, West Java, Indonesia

Health worker examines several vaccine vials beside open vaccine carriers at an immunisation facility.

Today, frontline health workers rely on the technology to eliminate guesswork when administering routine vaccines.

Health worker prepares a vaccine at a clinic while mothers and children wait nearby.

"I rely solely on the vaccine vial monitor as I perform my work... giving us the confidence that the medicine we inject into a child is still effective."

Grace Luzze, St. Charles Lwanga Hospital, Uganda

Health worker administers a vaccine to a baby held in their mother's arms at a clinic in Indonesia.

"I feel at peace knowing that my daughter is protected... I hope she will grow up to be strong, healthy, and happy."

Siska Rusmayanti, Mother, West Java, Indonesia