Novavax COVID-19 Vaccine 89% Effective Against UK COVID-19 Strain

Novavax recently announced that its COVID-19 vaccine candidate, NVX-CoV2373, was 89.3 percent effective in the Phase 3 UK clinical trial.

The trial also found that the vaccine was  95.6 percent against the original COVID-19 strain found in Wuhan, China.

The trial enrolled over 15,000 participants between 18 to 84 years of age, including 27 percent over the age of 65. The first analysis was based on 62 cases of COVID-19, of which 56 cases were observed in the placebo group and six cases were observed in the vaccine group.

The primary endpoint of the trial was based on the first confirmed coronavirus case with onset at least seven days after the second vaccination in a COVID-19 negative adult. 

Researchers uncovered efficacy during a period with high transmission and with the new UK variant strain of the virus circulating widely. Specifically, the strain was detected in over 50 percent of confirmed coronavirus cases.

“NVX-CoV2373 is the first vaccine to demonstrate not only high clinical efficacy against COVID-19 but also significant clinical efficacy against both the rapidly emerging UK and South Africa variants,” Stanley C. Erck, president and chief executive officer of Novavax, said in the announcement. 

“NVX-CoV2373 has the potential to play an important role in solving this global public health crisis. We look forward to continuing to work with our partners, collaborators, investigators and regulators around the world to make the vaccine available as quickly as possible,” Erck continued. 

NVX-CoV2373 contains a prefusion spike protein made using Novavax’s recombinant nanoparticle technology and saponin-based Matrix M adjuvant, the company explained.

Additionally, the candidate is stable at 2 degrees Celsius to 8 degrees Celsius and is shipped in a ready-to-use liquid formulation that permits distribution using existing vaccine supply chain channels, Novavax stated.

The company anticipates sharing further details of the UK trial as additional data become available.
“These are spectacular results, and we are very pleased to have helped Novavax with the development of this vaccine. The efficacy shown against the emerging variants is also extremely encouraging. This is an incredible achievement that will ensure we can protect individuals in the UK and the rest of the world from this virus,” said Clive Dix, chairman of the UK Vaccine Taskforce.

So far,  NVX-CoV2373 was found to be 60 percent effective in preventing mild, moderate, and severe COVID-19 in 94 percent of the study population that was HIV-negative in Novavax’s South African trial. 

Notably, the only severe case of COVID-19 reported was found in the placebo group. 

Novavax initiated the development of new constructs against the emerging strains of COVID-19 in early January. The company expects to select candidates for a booster or combination vaccines for the new strains soon.

There has also been significant progress on clinical trials in both the US and Mexico.

Novavax’s Mexico trial, PREVENT-19, has selected 16,000 participants and expects to complete targeted enrollment of 30,000 patients in the first half of February.  

The trial is being conducted along with the US government partnership known as Operation Warp Speed, which includes the Department of Defense, the Biomedical Advanced Research and Development Authority (BARDA), and the National Institute of Allergy and Infectious Diseases (NIAID).

Since the start of the pandemic, pharmaceutical companies have been racing to develop a COVID-19 vaccine. In mid-November, Pfizer-BioNTech’s COVID-19 vaccine, BNT162b2, was found to be over 90 percent effective in clinical trials.

Then earlier this week, the companies announced that the vaccine elicited antibodies that neutralize the SARS-CoV-2 UK strain.

Researchers found that in the sera of participants from a German Phase 1/2 trial, neutralization range was biologically equivalent to the Wuhan SARS-CoV-2 spike.

The neutralization of the pseudovirus bearing the UK strain spike by BNT162b2 means that COVID-19 caused by the UK virus variant can also be prevented by immunization with BNT162b2.