A third of Japan-donated Mpox vaccines wasted in DRC due to storage challenges

Approximately 35% of mpox vaccines donated by Japan to combat a dangerous new outbreak in the Democratic Republic of Congo are being wasted due to stringent preparation requirements that leave doses unusable within hours, the head of the country's mpox response has told Reuters.

Congo's mpox lead, Cris Kacita, reported that while over half a million people have been vaccinated, the loss rate for the Japanese LC16 vaccine is between 32% and 35%.

"We're really doing everything we can to prevent loss," Kacita stated.

The wastage occurs because each vial contains 250 powder doses that must be mixed before use and cannot be stored for more than a few hours once opened, meaning leftover vaccine is discarded if patient turnout is low.

Complex Logistics Hamper Outbreak Response

The LC16 vaccine, made by KM Biologics, is the only option approved for children and is being administered to those aged one and above.

However, its technical complexity—requiring a specific needle and administration technique—compounds the storage challenges.

Delivery is further hampered by the remote and politically unstable nature of some of the worst-affected provinces, though officials say the vaccine has still been effective in curbing the outbreak in the capital, Kinshasa.

Widespread Outbreak Persists Amid Global Downgrade

This year, Congo has recorded 53,657 mpox cases, down from 67,247 last year.

The World Health Organization notes that such vaccines typically have high wastage rates (5-50%) and recently downgraded the mpox outbreak from a global emergency due to declining rates.

However, transmission continues in 17 African countries, underscoring the critical need for effective vaccination campaigns despite the logistical hurdles that are causing significant waste of a vital medical resource.