Vaccine Distribution Security, Efficiency and Control

Posted: Wednesday, 30 June 2021 @ 11:44

The rapid implementation of mass vaccinations during the last six months is extremely welcome news. However, there is still much to do to distribute vaccines into communities worldwide with considerable logistics and distribution challenges. It is sure that the announcement of a vaccine will have got counterfeiters ears twitching and hands rubbing at the thought of the many millions to be made from (at best) water in a vial. The security and voracity of the vaccine supply chain will be critical to the supply process and public reassurance.

Unisto has a long history of supplying pharmaceutical manufacturers and distributors with security products that are written into their manufacturing processes. Many of the multi- national drug companies that have been working on a Covid-19 vaccine use Unisto security seals for their applications. Normally, seals are there to prevent accidental contamination providing a stop and think step before opening a keg or IBC and introducing the contents to the formulation and an audit trail of seal numbers for traceability.

We were called one day by a large pharmaceutical manufacturer that had accidentally dropped an opened plastic seal into a drug mix. The caller asked us for a detailed material specification of the seal in question and we were told that if we were unable to provide it then about £250,000 worth of part finished ingredients would have to be destroyed. After some anxious hours, our specifications came through and all was well, the processes could be completed; sighs of relief all round!

Security seals recommended for pharmaceutical and chemical use, at ambient or controlled room temperature, are most usually made of polypropylene or polyethylene. For low temperature use, 5°C and below, a metal seal is recommended, such as a stainless-steel cable seal or drum seal, as thermoplastics can become brittle at low temperatures.

From bulk to bottled or tabletted final product, seals are used throughout to control and safeguard each step.

For bulk materials that are supplied in stainless steel tanks and road tankers, a cable seal or reusable electronic seal is recommended to secure inlet and outlet valves. The benefit of using a reusable electronic seal is that sensors can be fitted to multiple manhole lids or other valves in series and will activate the seal if opened, generating a time and date stamped opening event. Cable seals or plastic seals used on each manhole and outlet valve can be costly and create considerable waste.

Intermediate bulk containers (IBC), in either stainless steel or high- density polyethylene HDPE, have sealable inlet and outlet valves.

For this application, either two seals (that can be numbered alike) or a single extra-long seal, such as the Modulo 1 (that can be 2.8 meters or more in length), can be used. Sometimes, the return cycle of an IBC for refilling is governed by whether the seal on the top cap remains unopened, confirming that it has not been filled with another material in the interim that could contaminate the next batch. In which case, two seals would be called for.


Kegs and drums moulded in HDPE can have a screw cap, where eyelets are aligned for sealing, or a lid that is locked tight with a galvanised slotted spring clamp for sealing. These different containers require a suitable seal to secure them. Unisto offers a range of drum closures and seals in plastic, metal or a combination of materials depending on the application and type of container being used. Kegs will normally require a pull through seal with a narrow ribbon diameter. The Compact Seal with 2mm diameter ribbon is the most suitable for this application.


For some higher security applications or where the pharmaceutical is to be stored at low temperature, a stainless-steel cable seal would be more suitable or perhaps a galvanised clip seal with stainless steel sealing wire. The cable or wire diameter can be as little as 1.2mm with a very wide choice of length to suit the application required. Drums and kegs often require a polyethene liner that is usually sealed with a numbered security tie. Plastic security ties can have integral spikes that grip the bag for greater security. That may be fine for sacks of post but, for fine chemicals or pharmaceutical ingredients, spikes have the potential to perforate the bags potentially allowing contaminates to enter. Spike free seals should be specified for liner bag applications. For best results when sealing a bag, please see step by step images.

Bag seals can also be manufactured in metal-detectable polypropylene which is ideal for food industry applications where online detectors are used to prevent any metal parts reaching the consumer in the finished product.

Raw, bulk drug or vaccine components require bulk handling and protection from contamination but, once tabletted, bottled, in vial or ampoule, it requires different security treatment, now the security defence is against counterfeiting and theft.

Normally, the consumer/end-user-packaged finished product will be in a branded carton within a wholesale bulk distribution outer grouping carton. Usually, anti-counterfeit measures are taken on the consumer packaging.

There are several measures that pharma companies take but the most frequently used is serialisation, where a serial number with bar or matrix code can trace the drug back to the point of manufacture and beyond, to the constituent parts of the drug. The war against counterfeiting is ongoing and ever changing.New technology is helping but the draw of patent drugs and medicines purchased at low cost on the internet is extremely hard to combat. The outer grouping carton can be security sealed in several ways to avoid theft or substitution.

Tamper evident void tape is used by several drug companies to seal the carton. Any attempt to remove the tape reveals a VOID message in thick adhesive residue left behind on the carton and in the removed tape. The tape can also be printed, branded, numbered and contain special UV sensitive inks to avoid any chance of substitution.

 An alternative to tape is a strapping seal that secures polypropylene straps around the carton at the crossing points, rendering the strapping tamper evident. The Straplock Seal was developed for the rollout of the Euro currency back in 2002, when large blocks of notes were distributed to banks within the eurozone and beyond. The blocks were shrink-wrapped, strapped, and sealed with Unisto Straplock.

Tamper evident VOID tape and/or Straplock Seals can also be used to secure shrink wrapped palletised cartons for additional security as well.
The next step is the distribution itself by road in sealed vans, trailers or freight containers. High value or sensitive cargo is most often secured by a bolt or heavy gauge cable seal which provides a barrier to all but the most determined thief. High security bolt seals are normally 12mm in diameter and cable seals have 5mm steel rope. 

One prominent pharmaceutical, biotech and life science logistic specialist is Biocair. This is a firm that has an in depth understanding of their customers’ needs and the precise handling and conditioning requirements of each load they carry. Biocair has a fleet of branded vans that have Unisto’s C2K Remote electronic reusable security seals permanently fitted to the rear doors. The opening of the door activates sensors that automatically generate a new seal number, verifying to customers the integrity of the load on arrival at the delivery point.

The speed of global shipments in drug distribution and development is of the essence and much use is made of airfreight containers (or unit load devices). These are most often sealed with 1.5 to 2mm diameter cable seals although thin ribbon plastic pull-up seals are also used to control access to the container contents.

In conclusion, the care that will be needed to ship consignments of such a vital and brand-new vaccine around the globe and get it to local vaccination centres will be immense. At the beginning and end of each step of distribution, security seals and temperature loggers will need to be checked and recorded. A robust audit trail will be vital to ensure the smooth rollout that will build public confidence and get this enormous vaccination program done.



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