Using Controlled Temperature Chain for Covid-19 Vaccines

Published by Ariel Arcebido on

Using Controlled temperature chain for covid-19 vaccines

What Is A Controlled Temperature Chain?

One method augmenting the immunization supply cold chains.  Using vaccines in a controlled temperature chain (CTC). This increases vaccine access and coverage, especially among hard-to-reach populations.

Controlled Temperature Chain permits some vaccines used in single vaccine delivery campaign situations to be kept outside of the traditional cold chain of +2 C to +8 C (35.6°F to 46.4°F).  Once outside the cold storage, the vaccines should be kept below temperature +40 C (104°F).  It is only for a predetermined period of time or right before vaccine administration.

Training and supervision are critical to the controlled temperature chain approach.  This is to ensure health workers are not confused about which vaccines are for the cold chain and which are not. A controlled temperature chain uses vaccines in campaigns and special strategies.

The controlled temperature chain approach also uses two specific and supplementary temperature monitoring tools:

  • A peak threshold temperature indicator allows a temporary view. All the same harmful exposures to extreme temperatures and;
  • The vaccine vial monitor (VVM).  It measures all heat exposures during unintentional temperature excursions. Limited to calibration for an upper-temperature limit of +37 C (98.6°F).

Controlled temperature chain so not only controls the cold chain excursions the prescribed approval process.  It also extends the flexibility and improves temperature monitoring. A compelling body of evidence shows CTC offers valuable opportunities like:

  • For optimizing supply chain efficiencies.
  • Safeguarding cold chain investments.
  • Ensure more protection for children and families from vaccine-preventable diseases.

Risk Mitigation Strategy

The World Health Organization (WHO) recommends CTC for locations that have cold chain difficulties. Where the immunization programs are hard to deliver. Hard to reach areas are at the lower bottom of the service delivery level. As distribution challenges are known to be prominent, including:

  • Lack of transportation infrastructure.  Easy to reach roads and large-capacity vehicles. Requiring vaccines transported in small transports. Often over uneven terrain by motorcycle, bicycle, or boat, when available, or on foot;
  • Time-consuming and long preparation of conditioned ice packs. To keep vaccines cold. Also avoiding freezing. It keeps the staff away from routine activities and wasting time packing the ice packs;
  • Constraints on time, staff, and equipment that result from maintaining vaccines. At appropriate temperatures with ice packs or reliable refrigeration. Which incur further staff and transportation costs; and

People may not be aware of the need for immunization or to travel to vaccine access points.

CTC eliminates the temperature excursions to have a safe and effective delivery of potent vaccines. CTC also applies efficiency improvements like eliminating burdensome journeys to renew ice stocks. Instead, redirecting limited resources to immunization services that are compromised during campaigns.

But CTC is not only easing the burdens of health workers at the last mile. But a risk of a mitigation strategy for problems that are not easily solved with traditional cold chain investments.

immunization information system
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Fundamentals For The Next Generation Of Supply Chains:

  • Leadership

While a majority of countries have some cold chain managers already in place. Just a few of them are familiar with cold chain management.  Nor do they have authority, accountability to improve the supply cold chain performance. Ministers of Health and immunization program managers now familiarize themselves with the supply chain training programs. Logistics professionals can make a difference in supply cold chain performance.

  • Continuous Improvement

The effective Vaccine Management (EVM) process sets the standard in supply cold chain performance. It out best other practices in the areas of vaccine management at each level of the health system. But only a handful of countries have achieved scores above the desired threshold of 80%.

National program managers and country-based agencies need to improve in the oversight mechanisms. Which other countries watch to make policy changes to improve their own supply cold chain performance.

  • System Design

Most vaccine supply chains follow the administrative hierarchy of the health system. It relies on overworked health and medical staff to perform logistics functions. Reorganizing the delivery, storage, and staffing configurations yield better results. Some third-world countries have revised their cold chain process in their regions. Introducing new staff positions, new cold chain equipment, and new logistics data systems to optimize performance.

This new process reportedly helped in regards of:

  • Reducing facility-level stockouts
  • Improved staff satisfaction
  • Increased rates of vaccine availability
  • Maximized coverage,
  • Boost savings.

Motivated by these results, other developing countries are also now considering making revisions to their cold chain process.

  • Logistics Data

Incomplete and inaccurate data collection systems generally compromised immunization programs. Making it difficult to use data to forecast vaccine requirements and to deliver the vaccines needed the most.

According to research, vaccine stockouts lasting one month or longer are present in one of every three countries globally. About 89% of these national stockouts compromise vaccine availability. Countries considered learning about new electronic data systems like the new system in India which was quickly utilized and led to lower stockouts. Thus, optimizing vaccine availability after 13months of continuous use.

Procurement staff learns how vaccine wastage. Session size is being used to determine optimal dose-per-vial in specific country situations.

improper handling of vaccines
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  • The Cold Chain

Accidental freezing still occurs in 33% of storage facilities in wealthy countries and 37% of facilities in lower-income countries.  Also, cold chain equipment is failing and underperforming in 20% and 50% of 55 countries.

Solutions to these problems are created at many different levels. One being, manufacturers releasing vaccine formulations that can withstand freezing.  Also, making sure managers are adept at how to monitor vaccines’ temperature in the cold chain.

National immunization staff and procurement officers know the importance of cold chain equipment. Designed to avoid freezing and operate in areas with unstable electricity power grids.

Program managers find the causes of equipment failures. They provide valuable and actionable information for technicians and procurement officers. Along with equipment manufacturers, and international partners.

How Controlled Temperature Chain fill the Supply Chain Gaps

Investments in the supply cold chain lead to better health facilities and transportation.  It cannot solve all the problems in the geographic barriers presented in the last miles. But CTC speeds up the vaccine delivery closer to the people in need especially those who have no access to health facilities. For example, bringing the hepatitis B vaccine to newborns by allowing temporary storage. Then, a midwife administered the vaccine without planning a cold chain. In this level of convenience, it is a wonder why there is no prominent investment in the immunization supply chain.

Supply chain investment provides the appropriate equipment for vaccines’ storage and transportation. Vaccine carriers destined for remote access points no longer need to put ice packs.

CTC allows more vaccine deliveries for longer distances within a better time frame. Rendering the supply chain more efficiently and effectively.

CTC’s lean approach, the hard-to-reach areas with little supply system become accessible. Also, vaccines need no package in single-dose vials used in a CTC. There is no need for specialized storage capacity.

The removal of ice packs from vaccine carriers offers higher transporter capacities. It also eliminates closed vial wastage to temperature-sensitive vaccines. This usually occurs during the final stages of delivery. Where the errors, cold chain failures, or accidental excursions are more likely present.

Altogether, by reducing the risk of failed delivery during the last mile.  CTC incurs significant cost savings, reduces the risk of vaccine wastage. Extends outreach, and increases higher vaccine coverage. It also safeguards and enables investments made earlier in the supply chain.

Vaccine manufacturers now developed a combination of vaccine and delivery devices. Which optimize the stability and qualify products for CTC use. Especially for those vaccines used in campaigns like village outreach and, outbreak response.

Impact of Controlled Temperature Chain

Peak temperature Threshold Indicator
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WHO has established a group under the Immunization Practices Advisory Committee to provide cooperation and policies among stakeholders.

Further evaluation, including economic analyses of early country experiences with CTC. It’s essential for informing the adoption of CTC for specific scenarios of use. Policymakers recognize CTC for its broader benefits of protecting and strengthening the supply chain. The demand for CTC-compatible vaccines encourages manufacturers to respond to the market. Allowing higher prices due to a CTC compatible status. Optimizing the relationship between supply and demand to the CTC agenda.


Stakeholders should continue innovating solutions to solve the challenges of vaccine delivery. Active responses from stakeholders can develop the impact to make a difference in the vaccine campaign.

The challenges of vaccine distribution, storage, and delivery are hard to understand but solvable. Many solutions were piloted and some were upgraded. Innovations are expected to drive further investment in immunization supply chains.

Investment in CTC is expected to be an important aspect of the supply chain.  A valuable tool for achieving coverage and equity goals for immunization.

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