Covid: Novavax vaccine appears 89% effective against virus

  • Video report by ITV News Science Editor Tom Clarke

UK phase three trials of the Novavax Covid-19 vaccine have found it demonstrated 89.3% efficacy against the virus.

Preliminary analysis has also showed the new UK variant was detected in more than half of the Covid-19 cases recorded in the trials, with the vaccine candidate shown to be 95.6% effective against the original strain and 85.6% effective against the variant.

It has also shown around 60% effectiveness against the South African strain of coronavirus, which has been worrying scientists due to concerns vaccines may not work against it.

The study involved more than 15,000 participants aged 18 to 84, with 27% aged over 65.

Clive Dix, chairman of the UK Vaccine Taskforce, said: “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.”

ITV News Science Editor analyses the latest developments with the Novavax vaccine

The UK has ordered 60 million doses of the Novavax vaccine, although it will require approval from the Medicines and Healthcare products Regulatory Agency.

The jab has an advantage over those from Pfizer/BioNTech and Moderna in that it can be stored in a regular fridge rather than needing ultra-cold storage.

Prime Minister Boris Johnson has hailed the announcement as “good news”.

He tweeted: “Good news that the @Novavax vaccine has proved effective in UK trials. Thank you to all the volunteers who made these results possible. “Our medicines regulator will now assess the vaccine, which will be made in Teesside. If approved, we have 60m doses on order.”

The vaccine is in the final stage of clinical trials until developers collate and submit data around its efficacy to regulators, who will then decide on its approval.

Because it is in trials, it can be referred to as 'experimental'.

There are three stages to clinical trials:

  • Phase 1 - Different doses are given to a small number of healthy volunteers to get some idea of the appropriate dose and to ensure that the material is safe. The main purpose here is to identify the right dose for the next step in the testing process as well as rule out any major safety problems.

  • Phase 2 - The vaccine is administered to a larger number of people, often between 100 or 200 but sometimes in the thousands. At this stage, researchers evaluate whether the vaccine can produce a consistent immune response and monitor for potential side effects.

  • Phase 3 - The vaccine can be tested to measure how well it protects against natural infection. These studies often include tens of thousands of healthy volunteers to prove that the vaccine prevents the disease and identify rare problems or side effects that only show up in larger population or sample sizes. The speed of the Phase 3 trials is also dependent on the rate of infection and the R value - if infection rates are very low then the trial could drag on for months on end.

The study assessed how effective the vaccine was when transmission of Covid-19 was high in the UK, and with the variant strain first identified in Kent circulating widely. The UK arm analysis, based on the first 62 cases of Covid-19 identified in the trial, reported 56 cases in people given a placebo (dummy) vaccine while six cases were in those given the Novavax jab. This part of the trial showed the jab was 89% effective against Covid-19. More than half of cases related to the UK strain of the virus, with the vaccine offering 86% protection against this particular strain. Against the original strain that has circulated since the start of the pandemic, the vaccine was 96% effective. Overall, data from more than 20,000 people, including a trial in South Africa, has now been reported in full. In the South African arm of the trial, where most cases of Covid-19 were the South African strain, the jab was 60% effective in preventing mild, moderate and severe coronavirus among those without HIV. Including the HIV positive participants, whose immune systems are compromised, overall the protection was just over 49%.

Professor Peter Openshaw, from Imperial College London, said the findings showed the jab “gives high levels of protection”.

However, he said the 60% finding for the South African variant was a “concern” due to suggestions that prior infection with earlier variants of Covid-19 may not completely protect against subsequent infection by the South African variant.

Oxford/AstraZeneca has said the reports are not a cause for concern. Credit: PA

Health Secretary Matt Hancock said the NHS stands ready to roll out the Novavax vaccine if it is approved by the medicines regulator. He 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. “The NHS stands ready to roll this vaccine out as quickly as possible to those most at risk if it is authorised.”