Trends in Viral Vector-Based Vaccines for Tuberculosis: A Patent Review (2010-2023)

Abstract

Tuberculosis (TB) is an ancient global public health problem. Several strategies have been applied to develop new and more effective vaccines against TB, from attenuated or inactivated mycobacteria to recombinant subunit or genetic vaccines, including viral vectors. This review aimed to evaluate patents filed between 2010 and 2023 for TB vaccine candidates. It focuses on viral vector-based strategies. A search was carried out in Espacenet, using the descriptors "mycobacterium and tuberculosis" and the classification A61K39. Of the 411 patents preliminarily identified, the majority were related to subunit vaccines, with 10 patents based on viral vector platforms selected in this study. Most of the identified patents belong to the United States or China, with a concentration of patent filings between 2013 and 2023. Adenoviruses were the most explored viral vectors, and the most common immunodominant Mycobacterium tuberculosis (Mtb) antigens were present in all the selected patents. The majority of patents were tested in mouse models by intranasal or subcutaneous route of immunization. In the coming years, an increased use of this platform for prophylactic and/or therapeutic approaches for TB and other diseases is expected. Along with this, expanding knowledge about the safety of this technology is essential to advance its use.

Keywords: patents; subunit; tuberculosis; vaccine; viral vector.

Figure 1

Patent search and screening.

Figure 2

Overview of patents identified through screening: (A) Main vaccine strategies identified in patent screening. From 216 patents identified as TB vaccine candidates, around 136 were related to subunit vaccine (protein or fragment-based), 32 to recombinant BCG, 16 to live attenuated, 16 to acid nucleic (DNA or RNA), 10 to viral vector and 6 to inactivated. (B) Patents based on viral vector for TB by country of application. Of the 10 selected patents, 4 belong to the United States of America (US), 2 to China (CN), and 2 to the World Intellectual Property Organization (WIPO). Russia (RU) and South Korea (KR) and presented one patent each. (C) Number of patents based on viral vector for TB per year of application (2010–2023).