Britain begins trial of multivariant COVID-19 vaccine booster

In the United Kingdom, a phase one study of a multivariant COVID-19 vaccination booster medication has begun with individuals aged 60 and up.

Gritstone, a US pharmaceutical firm, has begun the GRT-R910 study in cooperation with the University of Manchester and Manchester University NHS Foundation Trust. It will look at the drug’s ability to enhance the immune response of first-generation COVID-19 vaccines against a variety of Sars-Cov-2 variants that cause COVID-19.

“We think GRT-R910 as a booster vaccination will elicit strong, durable, and broad immune responses, which are likely to be critical in maintaining protection of this vulnerable elderly population who are particularly at risk of hospitalisation and death,” said Professor Andrew Ustianowski, Chief Investigator for the study from the North Manchester General Hospital.

“We now know the immune response to first generation vaccines can wane, particularly in older people. Coupled with the prevalence of emerging variants, there is a clear need for continued vigilance to keep COVID-19 at bay,” he said.

Part of Gritstone’s CORAL programme, GRT-R910 is described as a self-amplifying mRNA second generation SARS-CoV-2 vaccine – or SAM for short, which delivers antigens from both the spike and non-spike proteins.

“Our SAM COVID-19 vaccine is designed to drive robust CD8+ T cell responses, in addition to strong neutralising antibody responses, offering the promise of longer lasting immunity,” said Andrew Allen MD, Co-Founder, President and Chief Executive Officer of Gritstone.

He added: “Since viral surface proteins like the spike protein are evolving and sometimes partially evading vaccine-induced immunity, we designed GRT-R910 to have broad therapeutic potential against a wide array of SARS-CoV-2 variants by also delivering highly conserved viral proteins that may be less prone to genetic variation in the virus.

“Our hypothesis is that a different vaccine such as GRT-R910 might complement the primary immune response from pre-existing vaccination with a first generation COVID vaccine in such a way that it would provide more benefit than an additional dose of the same vaccine.”

The experiment will be conducted by the Research and Innovation Vaccine Team of the National Institute for Health Research (NIHR) Manchester Clinical Research Facility at Manchester Royal Infirmary, which is part of Manchester University NHS Foundation Trust (MFT).

The research, which is being funded by Health Innovation Manchester, is planned to enrol 20 participants, with findings on the vaccination anticipated in the first quarter of 2022. Gritstone and the National Institutes of Health will publish the results of the preclinical investigations that led to the creation of the vaccine later this year.

“We’re tremendously excited that this promising vaccine is to be trialed here in Manchester. As the only European site for this study, it is testament to the way our academic and clinical researchers have come together as part of the ‘One Manchester R&I’ approach to answer the questions the world needs answers to,” said Professor Ian Bruce, Chair of the Manchester COVID-19 Research Rapid Response Group (RRRG).

“Though the vaccine is being trialled in the over 60s, future studies will also examine its efficacy in other-vulnerable populations. If successful, we feel it has the potential to have play a significant role in the battle against COVID-19, which has so devastated vulnerable populations across the globe,” he said.

The study will examine dose, safety, tolerability, and immunogenicity of GRT-R910 at two dose levels at least four months after the second administration of their initial vaccine. GRT-R910 is also being investigated as part of a US National Institute of Health sponsored Phase 1 study.