Adjuvants are vaccine components that help activate the immune system and improve immune responses. MHRP scientists developed a family of new adjuvants called the Army Liposome Formulation (ALF).
ALF adjuvant was first conceived in the 1980s and designed, manufactured and tested by the U.S. Army and collaborators in human trials of candidate malaria and HIV-1 vaccines in the 1990s. Inspired by the success of a commercial adjuvant used in a licensed shingles vaccine, in 2015 Army scientists developed two novel improvements of ALF, called ALFA and ALFQ. An overview of this adjuvant work was published in the Expert Review of Vaccines.
In 2021, MHRP and partners launched a Phase 1 comparative adjuvant study in Kericho, Kenya, to evaluate experimental HIV-1 Env DNA and gp145 vaccines combined with different adjuvants, including ALFA. The Army-funded RV460 study will evaluate whether an adjuvant can improve immunogenicity of the candidate vaccines. It will also help characterize the differences between the adjuvants and the role of adjuvants in priming versus boosting.
In a 2020 preclinical study conducted by MHRP, an HIV vaccine formulated with AFLA elicited stronger immune responses than a vaccine with a more commonly used alum adjuvant. Findings from the study were published in PLOS Pathogens.
The ALFQ type was awarded a patent in late 2019, and preclinical studies demonstrated the product to be strongly potent as a vaccine adjuvant. ALFQ will enter its first HIV-related human clinical trial in Kenya and Thailand in 2021.
In 2020 a clinical study using ALF in two malaria vaccine formulations began at the Clinical Trial Center at WRAIR. Several additional human safety and immunogenicity trials are planned which will employ members of the ALF family of adjuvants including a WRAIR-developed vaccine to prevent COVID-19, three candidate HIV-1 vaccines and a candidate bacterial (Campylobacter jejuni) diarrhea vaccine. Another human trial is planned with ALFA as the adjuvant in an immunotherapeutic heroin vaccine.