The durability of vaccine-induced protection: an overview

ABSTRACT

Introduction

Current vaccines vary widely in both their efficacy against infection and disease, and the durability of the efficacy. Some vaccines provide practically lifelong protection with a single dose, while others provide only limited protection following annual boosters. What variables make vaccine-induced immune responses last? Can breakthroughs in these factors and technologies help us produce vaccines with better protection and fewer doses? The durability of vaccine-induced protection is now a hot area in vaccinology research, especially after COVID-19 vaccines lost their luster. It has fueled discussion on the eventual utility of existing vaccines to society and bolstered the anti-vaxxer camp. To sustain public trust in vaccines, lasting vaccines must be developed.

Areas covered

This review summarizes licensed vaccines’ protection. It analyses immunological principles and vaccine and vaccinee parameters that determine longevity of antibodies. The review concludes with challenges and the way forward to improve vaccine durability.

Expert opinion

Despite enormous advances, we still lack essential markers and reliable correlates of lasting protection. Most research has focused on humoral immune responses, but we must also focus on innate, mucosal, and cellular responses – their assessment, correlates, determinants, and novel adjuvants. Suitable vaccine designs and platforms for durable immunity must be found.

KEYWORDS:

• Durability
• immunity
• immune responses
• persistence of immunity
• vaccines
• vaccinology

Article highlights

• Only a handful of currently licensed vaccines provide long-lasting protection

• There are still gaps in our understanding of reliable correlates of durable protection.

• Induction of vigorous germinal center reaction and induction of a large number of long-lasting plasma cells along with the formation of memory B-cells and memory T-cells is essential for durable vaccine-induced protection

• There are several determinants of the longevity of antibody response, such as vaccine platform, target pathogen, vaccinee’s characteristics, environmental and genetic factors

• New developments in the field of vaccinology, like improved vaccine design, novel adjuvants, and molecular delineation of antigenic forms, hold hope for developing durable vaccines

• Further research is needed to identify the optimal antigen delivery methods and formulations that result in prolonged antigen availability and can elicit long-lasting and protective immunity

Declaration of interests

The authors have no 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. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

Reviewer disclosures

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

Author contributions

VMV and PK have substantially contributed to the conception and design of the review article and interpreting the relevant literature, and been involved in writing the review article or revised it for intellectual content.

Additional information

Funding

This paper was not funded.