The trial, which has been taking place in the UK since July 2020 and involves 15,000 participants, has also shown that the vaccine is effective at targeting the new so-called UK strain of the virus, which emerged in Kent at the end of last year.
Just over 4,000 people involved in the trial (27%) were over 65. Interim data showed that the vaccine was 95.6% effective at protecting against the original COVID-19 strain and 85.6% effective against the UK variant, with an overall effectiveness of 89.3%.
The trial found there were 62 cases of COVID-19, 56 of which were in the placebo group and six in the vaccinated group. There was only one severe case of COVID-19, which occurred in the placebo group. Of the positive cases, 32 were the new UK variant of the virus, 24 were the original strain and 6 were unknown.
A separate phase 2b trial of the vaccine in South Africa, involving 4,000 participants, suggests that it also provides some protection against the new South African variant. The company is now planning to develop a vaccine specifically targeting the South African variant which it intends to begin trialling in the spring.
The Novovax vaccine is a protein adjuvant vaccine and can be stored in standard vaccine fridges. It is one of seven jabs the UK government has pre-ordered and the US-based company intends to manufacture the UK's supply in Teeside.
Novovax is submitting rolling data on its trials to the Medicine and Healthcare products Regulatory Agency (MHRA).
Health secretary Matt Hancock said: 'This is positive news and, if approved by the medicines regulator, the Novavax vaccine will be a significant boost to our vaccination programme and another weapon in our arsenal to beat this awful virus.
'I’m proud the UK is at the forefront of another medical breakthrough and I want to thank the brilliant scientists and researchers, as well as the tens of thousands of selfless volunteers who took park in clinical trials.'
Vaccines minister Nadhim Zahawi said: 'Having taken part in Novavax’s vaccine trial myself, I am particularly thrilled to see such positive results. I want to thank the thousands of trial volunteers, without whom these results would not have been possible.'
The UK vaccine portfolio
Approved by MHRA
- Pfizer/BioNTech - 40m doses
- Oxford/AstraZeneca - 100m doses
- Moderna - 17m doses (first doses due to be delivered to the UK in April/May)
In clinical trials
- Novavax - Phase 3 - 60m doses
- Janssen - Phase 3 - 30m doses
- GSK/Sanofi - Phase 1/2 - 60m doses
- Valneva - Phase 1/ 2 - 60m doses secured, with an option to acquire a further 130m if the vaccine is approved by the MHRA