New pan-coronavirus vaccine passes key experiments, demonstrates protection

by Sarah Avery, Duke University

Two doses of RBD-scNP vaccination protected mice from challenges of SARS-CoV-2 variants and other betacoronaviruses. a Schematic of the mouse challenge studies. 11-month-old female BALB/c mice (n = 10 per group) were immunized intramuscularly twice with adjuvanted RBD-scNP and challenged with SARS-CoV-2 mouse-adapted 10 (MA10) WA-1, SARS-CoV-2 MA10 Beta variant, SARS-CoV-1 mouse-adapted 15 (MA15), or Bat coronavirus (CoV) RsSHC014 MA15. GLA-SE was used as adjuvant in the SARS-CoV challenge study, and 3M-052-Alum was used in the other challenge studies. b Weight loss (n = 10 per group) and lung virus titers (n = 10 per group) at 4 days post-infection (dpi) of the SARS-CoV-2 MA10 WA-1 challenged mice. c Weight loss (n = 5 per group) and lung virus titers (n = 4 per group) at 2 dpi of the SARS-CoV-2 MA10 Beta variant challenged mice. d Weight loss (n = 10 per group) and lung virus titers (n = 5 per group) at 2 dpi of the SARS-CoV-1 MA15 challenged mice. e Weight loss (n = 10 per group) and lung virus titers (n = 10 per group) at 4 dpi of the Bat CoV RsSHC014 MA15 challenged mice. For weight curves, data are presented as mean values ±SEM. For lung virus titers, each dot indicates one mouse and bars indicate geometric mean values of each group. P-values: ns not significant, *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001, Two-sided Wilcoxon rank sum exact test. Credit: Nature Communications (2022). DOI: 10.1038/s41467-022-33985-4

In laboratory and primate tests, a new pan-coronavirus vaccine developed by the Duke Human Vaccine Institute (DHVI) has demonstrated wide protection against SARS-CoV-2 viruses and variants, including omicron BA.5.

Publishing in the journal Nature Communications, the DHVI and collaborating researchers reported that three doses of the pan-coronavirus vaccine induced neutralizing antibodies against beta, delta and omicron variants, including the subvariant BA.5.

The vaccine was also tested by exposing vaccinated animals to various SARS-CoV-2 strains. It demonstrated protection against infection from the original SARS-CoV-2 strain, as well as beta and delta variants.

“This provides proof-of-concept for a first generation pan-SARS-like virus vaccine,” said Barton F. Haynes, M.D., director of the DHVI.

The vaccine candidate is a combination of a nanoparticle antigen developed at Duke, along with an adjuvant—an ingredient that boosts a vaccine’s effects—formulated by the Access to Advanced Health Institute. The adjuvant formulation, 3M-052-AF, significantly enhanced the immune responses in the animals when combined with the antigen.

“While SARS-CoV-2 continues to mutate during the ongoing pandemic, there are conserved regions on the virus that our vaccine will continue to successfully bind to, regardless of mutations,” Haynes said. “That will be critical for present and future protection.”

The vaccine candidate will now move to production and an initial Phase I clinical trial in humans. Ongoing research will focus on developing the vaccine as a booster for the currently vaccinated population, aiming to optimize the induction of antibodies that would neutralize new variants.