Ensuring quality and integrity of vaccines throughout the cold chain: the role of temperature monitoring

ABSTRACT

Introduction

Vaccines have continually proven their inestimable value to the world through the eradication of smallpox, gains achieved toward a polio-free world, and controlling other vaccine-preventable diseases. Although vaccines require certain temperatures and conditions to maintain their potency, supply chain controls vary greatly at different legs of the global journey. Vaccine manufacture is closely managed, but inconsistencies plague the cold chain when vaccines are shipped and stored in variable conditions. Monitoring vaccine temperatures throughout the cold chain is of paramount importance to ensure quality. The emerging COVID-19 vaccines present the world with new challenges and additional opportunities to establish best practices for safeguarding human health.

Areas covered

We review the risks associated with the vaccine cold chain that require temperature monitoring throughout shipment and storage. Electronic and chemical monitoring devices are compared along with data needs. Regulatory oversight and guidance are also discussed.

Expert opinion

Regulatory oversight has contributed to the creation of a risk management and quality culture among private sector players in the vaccine field. Meanwhile, the public sector (the main player at the country level) remains largely untouched by regulatory oversight. Adherence to best practices shall only be possible with increased regulatory oversight of public sector operations.

KEYWORDS:

• Cold chain
• supply chain
• temperature monitoring
• electronic devices
• vaccines
• risk management
• quality
• regulation

Article highlights

• Vaccines are time and temperature sensitive biological products and are affected by exposure to freezing temperatures, to heat and to light. When vaccine potency is lost it cannot be regained. It is therefore essential to ensure vaccine quality.

• The primary crux of the vaccine cold chain is temperature monitoring. As all vaccines need to be maintained within a specific temperature range, continuous monitoring of vaccine temperatures is imperative, particularly as products travel through varying conditions.

• Electronic devices are superior to chemical systems based on their data capabilities that meet the requirements of key players in vaccine cold chain operations.

• Introduction of new vaccines (especially COVID-19 vaccines) brought more complexity to cold chain operations and therefore to temperature monitoring.

• Following manufacturing, vaccines typically reach end users through a highly complex cold chain operation, going through a number of ‘touchpoints’ or process and service exchanges between organizations and individuals. Touchpoints present substantial risks of improper handling during these exchanges, typically resulting in temperature violations.

• Regulatory oversight has contributed to the creation of a risk management and quality culture in the private sector. Although the public sector is the main player at the country level of vaccine management operations, the public sector is mostly untouched by regulatory oversight. The ability to demonstrate compliance with good storage and transport practices shall only be possible with increased regulatory oversight of public sector operations.

Declaration of interest

U Kartoglu has worked with WHO as a consultant on authoring the guidelines on the international packaging and shipping of vaccines including requirements for candidate COVID-19 vaccines as well as revising specifications and verification protocols for temperature monitoring devices. He has also worked as a consultant for Temptime Corporation, Insite Enterprises, Inc., Sensitech, Inc., and UNICEF on vaccine-quality related issues. The author declares that he has no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. H Ames works as General Manager for Life Sciences at Sensitech, a Carrier Company. Sensitech manufactures temperature monitoring products and provides expert services to help customers protect their temperature sensitive products. He also serves as a member of the Parenteral Drug Association’s Pharmaceutical Cold Chain Interest Group and sits on the International Air Transport Association’s Time and Temperature Task Force. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

Reviewer disclosures

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Author contributions statement

Both authors have substantially contributed to the conception and design of the review article and interpreting the relevant literature, and have been involved in writing and revising the review article.

Correction Statement

This article has been republished with minor changes. These changes do not impact the academic content of the article.