Novavax vaccine trial shows 90% efficacy in combating Covid-19

Novavax’s Covid-19 vaccine was 90 per cent effective in its late stage trial in the US and Mexico and proved it can tackle the virus variants of concern, opening the way for the approval of another shot to control the pandemic.

The Maryland-based company — which after 33 years, has not yet had a product approved — said its vaccine offered 100 per cent protection against moderate and severe Covid-19. All cases of Covid-19 in the vaccinated group were mild. 

The two-dose vaccine showed 93 per cent efficacy against the variants of concern and the emerging variants of interest, which represented the vast majority of cases. It was 91 per cent effective for people in high risk groups, such as the over-65s and those suffering from underlying conditions.

Stanley Erck, Novavax’s chief executive, said the vaccine maker is now “one step closer” to “addressing the critical and persistent global public health need for additional Covid-19 vaccines”. 

“Novavax continues to work with a sense of urgency to complete our regulatory submissions and deliver this vaccine, built on a well understood and proven platform, to a world that is still in great need of vaccines,” he said. 

The company uses a traditional method for its vaccine but grows its protein in moth cells, to scale up rapidly, and then puts it in nanoparticles. This antigen, which teaches the body to recognise the spike protein, is boosted by a proprietary adjuvant.

The data from the trial of almost 30,000 participants in the US and Mexico is similar to the results previously published from Novavax’s trials in the UK and South Africa. Then, it found that the vaccine was 96 per cent effective against the original strain of Sars CoV-2. 

But the vaccine was significantly less effective against the Beta variant that first emerged in South Africa. Last week, Novavax said that a vaccine tailored for this variant elicited immune responses in animal and human studies against Beta and other strains, potentially paving the way for it to be used as a booster.

While the trial data from outside the US was published in March, the company has still not finalised its regulatory submissions and has suffered production problems that have delayed its schedules. It said on Monday that it needed to meet chemistry, manufacturing and controls requirements.

Novavax received $1.6bn from Operation Warp Speed, helping fund production of 100m doses. The UK government agreed to purchase 60m doses, as part of a deal where Novavax would produce a key component of the vaccine in Stockton-on-Tees.

The vaccine also proved safe in the US and Mexico trial, with few serious adverse events, equally balanced between participants who took the shot and those on placebo. The most common side effects were fatigue, headache and muscle pain, as with many vaccines.