Immunogenicity phase II study evaluating booster capacity of nonadjuvanted AKS-452 SARS-Cov-2 RBD Fc vaccine

David G. Alleva, Eline A. Feitsma, Yester F. Janssen, Hendrikus H. Boersma, Thomas M. Lancaster, Thillainaygam Sathiyaseelan, Sylaja Murikipudi, Andrea R. Delpero, Melanie M. Scully, Ramya Ragupathy, Sravya Kotha, Jeffrey R. Haworth, Nishit J. Shah, Vidhya Rao, Shashikant Nagre, Shannon E. Ronca, Freedom M. Green, Stephen A. Shaw, Ari Aminetzah, Schelto KruijffMaarten Brom, Gooitzen M. van Dam, Todd C. Zion*

*Bijbehorende auteur voor dit werk

OnderzoeksoutputAcademicpeer review

11 Downloads (Pure)


AKS-452, a subunit vaccine comprising an Fc fusion of the ancestral wild-type (WT) SARS-CoV-2 virus spike protein receptor binding domain (SP/RBD), was evaluated without adjuvant in a single cohort, non-randomized, open-labelled phase II study (NCT05124483) at a single site in The Netherlands for safety and immunogenicity. A single 90 µg subcutaneous booster dose of AKS-452 was administered to 71 adults previously primed with a registered mRNA- or adenovirus-based vaccine and evaluated for 273 days. All AEs were mild and no SAEs were attributable to AKS-452. While all subjects showed pre-existing SP/RBD binding and ACE2-inhibitory IgG titers, 60–68% responded to AKS-452 via ≥2-fold increase from days 28 to 90 and progressively decreased back to baseline by day 180 (days 28 and 90 mean fold-increases, 14.7 ± 6.3 and 8.0 ± 2.2). Similar response kinetics against RBD mutant proteins (including omicrons) were observed but with slightly reduced titers relative to WT. There was an expected strong inverse correlation between day-0 titers and the fold-increase in titers at day 28. AKS-452 enhanced neutralization potency against live virus, consistent with IgG titers. Nucleocapsid protein (Np) titers suggested infection occurred in 66% (46 of 70) of subjects, in which only 20 reported mild symptomatic COVID-19. These favorable safety and immunogenicity profiles support booster evaluation in a planned phase III universal booster study of this room-temperature stable vaccine that can be rapidly and inexpensively manufactured to serve vaccination at a global scale without the need of a complex distribution or cold chain.

Originele taal-2English
Aantal pagina's12
Tijdschriftnpj Vaccines
StatusPublished - 21-feb.-2024


Duik in de onderzoeksthema's van 'Immunogenicity phase II study evaluating booster capacity of nonadjuvanted AKS-452 SARS-Cov-2 RBD Fc vaccine'. Samen vormen ze een unieke vingerafdruk.

Citeer dit