EPI-backed coronavirus vaccine from Novavax starts trials

A coronavirus vaccine developed by US biotech Novavax with $388m in funding from the Bill Gates-backed Coalition for Epidemic Preparedness and Innovation (CEPI) is starting human testing.

Maryland, US-based Novavax said the first healthy volunteers would be dosed with NVX-CoV2373 in the phase 1/2 trial today, with results from the initial phase 1 stage expected in July.

The first stage will enrol around 130 subjects aged 18 to 59 at two clinical centres in Australia, and will test two versions of NVX CoV2373, one with Novavax’ Matrix-M adjuvant and one without.

If the initial assessment is positive the phase 2 stage will include additional sites around the world and a broader age range.

NVX-CoV2373 has become the tenth vaccine against SARS-CoV-2 – the virus that causes COVID-19 – to reach the human testing stage, according to the World Health Organisation’s latest update dated 22 May, which says another 114 candidates are in preclinical testing.

It is also the first based on a protein subunit structure, and includes a full-length SARS-CoV-2 glycoprotein administered in a nanoparticle delivery vehicle.

CEPI’s backing means that Novavax will also be able to manufacture 100m doses of NVX-CoV2373 by the end of the year, and potentially as many as a billion doses during 2021 if the initial clinical trials are successful.

First results with CanSino Bio vaccine

As Novavax announced the start of its trial, one of the lead companies in coronavirus vaccine development – China’s CanSino Biological – published phase 1 results with its adenovirus-based candidate in medical journal The Lancet.

The preliminary results show that the vaccine – which delivers DNA into human cells that causes the production of viral antigens – can stimulate immune responses against SARS-CoV-2 and appears to be safe.

The researchers caution it is too soon to determine whether those responses will protect against infection. The patients generated antibodies that bind to the virus, but it’s not yet established whether they will neutralise it or are being produced in sufficient numbers.

CanSino’s trial was conducted in 108 patients recruited in Wuhan, the epicentre of China’s coronavirus outbreak, so it is possible some recruits had already been exposed to the virus and so could already have immunity.

It’s a similar picture with Moderna’s RNA-based vaccine mRNA-1273 which generated its first phase 1 data last week, setting up a phase 3 trial. Moderna has some data showing the antibodies stimulated by its vaccine neutralise SARS-CoV-2 in the lab.

Meanwhile, the lead investigator in the trial of another adenoviral SARS-CoV-2 vaccine in development at Oxford University has suggested that falling rates of coronavirus infection in the UK could mean its just-started phase 3 trial only has a 50% chance of showing efficacy.

Adrian Hill, director of the university’s Jenner Institute, told The Sunday Telegraph that vaccine developers are in “a race against the virus disappearing, and against time”. Last week, AstraZeneca said it had capacity to produce a billion doses of the ChAdOx1 n-CoV-19 vaccine, and had received orders for 400m doses from the US and 100m doses from the UK.