Development of thermostable vaccine adjuvants

ABSTRACT

Introduction

The importance of vaccine thermostability has been discussed in the literature. Nevertheless, the challenge of developing thermostable vaccine adjuvants has sometimes not received appropriate emphasis. Adjuvants comprise an expansive range of particulate and molecular compositions, requiring innovative thermostable formulation and process development approaches.

Areas covered

Reports on efforts to develop thermostable adjuvant-containing vaccines have increased in recent years, and substantial progress has been made in enhancing the stability of the major classes of adjuvants. This narrative review summarizes the current status of thermostable vaccine adjuvant development and looks forward to the next potential developments in the field.

Expert opinion

As adjuvant-containing vaccines become more widely used, the unique challenges associated with developing thermostable adjuvant formulations merit increased attention. In particular, more focused efforts are needed to translate promising proof-of-concept technologies and formulations into clinical products.

KEYWORDS:

• Thermostable
• vaccine adjuvant
• lyophilization
• spray drying
• aluminum salts
• emulsions
• liposomes
• nanoparticles

Article highlights

• Adjuvants are increasingly employed in modern vaccine development and their unique properties require well-designed approaches to achieve thermostability

• Approaches to achieve thermostability have been reported for the major classes of adjuvants including aluminum salts, oil-in-water emulsions, and liposomes

• Additional thermostable platforms include nano/microparticles and formulations designed for alternative routes of delivery such as mucosal or dermal

• Developing thermostable adjuvant formulations should help facilitate worldwide distribution of effective vaccines

Acknowledgments

The authors thank Dan Stoughton and Larry Wolfraim from NIAID/NIH for careful review of the text and helpful suggestions.

Declaration of interest

Y Qi and C Fox are employees of the Infectious Disease Research Institute, which has product assets related to thermostable vaccine adjuvant formulations including patents and patent applications. 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.

Additional information

Funding

This work was supported by federal funds from the National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health (NIH), Department of Health and Human Services, under Contract HHSN272201400041C.