Journal Article

Humoral and cellular immune responses after 6 months of a heterologous SARS-CoV-2 booster with the protein-based PHH-1V vaccine in a phase IIb trial

Cañete, Manuel, Forner Giner, Maria José, Esteban, Ignasi, McSkimming, Paula, Lucas, Rafael Ortí, Clotet, Bonaventura, Otero Romero, Susana, Garriga, Carme, Pradenas, Edwards, Bailón, Lucía, López Fernández, María Jesús, de la Villa, Sofía, García, Patricia Muñoz, Blanco, Julià, Meijide, Susana, Barreiro, Antonio, Rodríguez Fernández, Sara, Ferrer, Laura, Güell, Irina, Raïch-Regué, Dàlia, Soriano, Alex, Camacho-Arteaga, Lina, Benet, Susana, Gallemí, Marçal, Navarro-Pérez, Jorge, Bernad, Laia, Pérez-Caballero, Raúl, Martínez-Gómez, Xavier, Molto, Jose, Martí Lluch, Ruth, Corpes Comes, Aida, Madrenas, Laia, Ramos, Rafel, Corominas, Júlia, Torroella, Èlia, Prat, Teresa, Nava, Jocelyn, Izquierdo-Useros, Nuria, Plana, Montserrat, Taleb, Rachel Abu, Aurrecoechea, Elena, Borobia, Alberto M., Moros, Alexandra, Queiruga Parada, Javier, Alvarez-Mon, Melchor, Troncoso, Daniel, González-González, Luis, Arribas, Jose R., G. Prado, Julia, Vázquez Jiménez, María del Mar, Prenafeta, Antoni, Trinité, Benjamin, Arana-Arri, Eunate, Imaz-Ayo, Natale, Anagua, Jesse Omar

2025

Overview

The HIPRA-HH-2 was a multicentre, randomized, active-controlled, double-blind, non-inferiority phase IIb clinical trial comparing the immunogenicity and safety of the PHH-1V adjuvanted recombinant vaccine as a heterologous booster against homologous booster with BNT162b2. Interim results demonstrated strong humoral and cellular immune response against the SARS-CoV-2 Wuhan-Hu-1 strain and the Beta, Delta, and Omicron BA.1 variants up to day 98 post-dosing. Here we report that these responses with PHH-1V are sustained up to 6 months, including in participants over 65 years, despite their smaller sample size. The PHH-1V booster was non-inferior in eliciting neutralizing antibodies for SARS-CoV-2 Omicron XBB.1.5 variant compared to BNT162b2 after 6 months. No severe COVID-19 cases occurred in any group, and mild cases were similar (50.4 % for PHH-1V vs. 47.8 % for BNT162b2). While both groups may have reached comparable immunity levels, these findings suggest that the PHH-1V vaccine provides long-lasting immunity against various of SARS-CoV-2 variants. ClinicalTrials.gov Identifier: NCT05142553

• Publisher: Elsevier Ltd,Elsevier Limited
• Subject: Adult / Age groups / Aged / Allergy and Immunology / Antibodies / Antibodies, Neutralizing - blood / Antibodies, Neutralizing - immunology / Antibodies, Viral - blood / Antibodies, Viral - immunology / BNT162 Vaccine - immunology / cell-mediated immunity / Clinical trials / COVID-19 / COVID-19 - immunology / COVID-19 - prevention & control / COVID-19 infection / COVID-19 vaccines / COVID-19 Vaccines - administration & dosage / COVID-19 Vaccines - adverse effects / COVID-19 Vaccines - immunology / Double-Blind Method / Female / Heterologous booster / Humans / Immune response / Immune response (cell-mediated) / Immune response (humoral) / Immune system / Immunity / Immunity (Disease) / Immunity, Cellular / Immunity, Humoral / Immunization, Secondary - methods / Immunogenicity / Immunogenicity, Vaccine / Infections / Male / Middle Aged / Population / Protein-based vaccine / Proteins / recombinant vaccines / sample size / SARS-CoV-2 / SARS-CoV-2 - immunology / Severe acute respiratory syndrome coronavirus 2 / Vaccines / Vaccines, Synthetic - administration & dosage / Vaccines, Synthetic - immunology