Medical Health Cluster

7 febrero, 2022

Novavax COVID Jab Approved by MHRA

The Medicines and Healthcare products Regulatory Agency (MHRA) has today given conditional marketing authorisation (CMA) to Nuvaxovid, a COVID-19 vaccine developed by Novavax. It becomes the fifth COVID jab to which the MHRA has given regulatory approval.

In the UK phase 3 trial, with over 15,000 participants, overall efficacy was 89.7%, efficacy against the Alpha variant 86.3%, and there were no severe cases seen, compared with five in the placebo group.

A full course of Nuvaxovid involves two separate 0.5 mL injections with the second dose given 3 weeks after the first. As with all vaccines, people with an allergy to one of its components should not receive the vaccine.

The CMA authorises the vaccine in people aged 18 and over. However, a spokesperson for the company said it planned to apply for regulatory expansion to 12- to 17-year-olds within the next couple of months. Administration of Nuvaxovid in pregnancy should only be considered when the potential benefits outweigh any potential risks for the mother and foetus.

Professor Sir Munir Pirmohamed, chair of the Commission on Human Medicines, said: “We are pleased to say that we have advised that the benefit-risk balance of Nuvaxovid is positive.

“Nuvaxovid is distinct from other COVID-19 vaccines currently in use in the UK as it uses recombinant protein-based technology, which has been used for many years in the development of vaccines to prevent other illnesses, for example hepatitis B. In reaching its decision, the MHRA considered the results of two large clinical trials involving nearly 50,000 participants.”

In a statement, Stanley C. Erck, president and CEO of Novavax, said: “We are proud that Nuvaxovid will be the first protein-based vaccine option authorized by MHRA as the United Kingdom tackles this next phase of the pandemic.

“We thank the agency for its thorough review process and are tremendously grateful to the clinical trial participants and trial sites in the UK, as well as the Vaccines Taskforce, for their ongoing support and vital contributions to this program.”

Boosters Likely to be Needed

There is increasing evidence that vaccine boosters will be needed to maintain protection, and so it is likely that we will be looking at repeated vaccinations, according to a company spokesperson. Novavax had previously announced an agreement with the UK Vaccines Taskforce for up to 60 million doses of Nuvaxovid. A spokesperson said that their manufacturing capacity was anticipated to be up to 2 billion doses in 2022 alone, giving them a significant advantage in securing global access.

Responding to the announcement, Dr Clive Dix, former chair of the UK Vaccine Taskforce, said: “This is excellent news as the clinical data on this vaccine is excellent and the strong cellular response should make this an excellent vaccine for boosting next winter.  Not only do we expect a strong durable response but also good stability at fridge temperature, so it can be rolled out with the flu vaccine next winter as part of the winter campaign.

“This should replace the need to buy more Pfizer and Moderna vaccine and save the UK Government a considerable amount of money.”

Different Technology

Nuvaxovid is a recombinant, adjuvanted vaccine composed of purified full-length SARS-CoV-2 recombinant spike protein, adjuvanted with Matrix-M, which enhances the magnitude of the S protein-specific immune response.  Matrix-M is Novavax’s patented preparation of extracts from the bark of Quillaja saponaria Molina, the Chilean soapbark tree, which has strong adjuvant and antiviral properties, together with cholesterol and phospholipid.

The spike protein in Nuvaxovid is produced by recombinant DNA technology using a baculovirus expression system in an insect cell line derived from Sf9 cells of the Spodoptera frugiperda species, commonly known as the fall armyworm.

The two vaccine components elicit B- and T-cell immune responses to the S protein, including neutralising antibodies, which may contribute to protection against COVID-19.

“The technology is really very different from both the viral and the mRNA vaccines,” according to Filip Dubovsky, chief medical officer at Novavax. “The full length spike protein does have common epitopes that span all the variants, and in fact epitopes that go back even to the original SARS. So the benefit of the native conformation… is that it’s pretty much identical to the virus naturally. On top of that, the adjuvant really focuses and broadens the immune response.

 “It has the ability to neutralise a broad range of variants … [and]… deal with antigenic spread.”

The approach also enables rapid development and scale in response to strain changes. Novavax has already initiated development of an Omicron-specific vaccine, and has a combined covid-influenza vaccine in the pipeline.

Nuvaxovid is packaged as a ready-to-use liquid formulation in vials containing 10 doses. The vaccination regimen calls for two 0.5-ml doses (5 mcg antigen and 50 mcg Matrix-M adjuvant) given intramuscularly 21 days apart. The vaccine is stored at 2-8° Celsius, enabling the use of existing vaccine supply and cold chain channels. The current assigned shelf life of the vaccine in Great Britain is 9 months.

Safety Monitoring

Following today’s announcement, the next step will be for the Joint Committee on Vaccination and Immunisation (JCVI) to consider its use as part of the UK’s vaccination programme. June Raine, MHRA chief executive, said: “Our approval of Nuvaxovid today follows a rigorous review of the safety, quality and effectiveness of this vaccine, and expert advice from the Government’s independent scientific advisory body, the Commission on Human Medicines.

“We are continuing our vital safety work in monitoring the use of all COVID-19 vaccines, to ensure that their benefits in protecting people against COVID-19 disease continue to outweigh any risks. We also carry out independent batch testing on all the approved COVID-19 vaccines to ensure that every batch meets the expected quality standards.”

No significant safety signals have been seen in trials according to Novavax, and specifically neither the myocarditis nor the clotting issues that have been a problem with existing vaccines, according to Paul Heath, professor of paediatric infectious diseases at St George’s University of London and chief investigator on the UK trial.

He said during a media briefing: “90% of individuals 12 and above are vaccinated and around 82% have had their second dose… 10% and 18% respectively have not had their first and second doses.

“Anecdotally, we do believe there are people out there who have been waiting for a vaccine that has been developed with a more traditional platform.

“Those who haven’t been vaccinated yet may be more inclined to be vaccinated.

“There is still an important need for a vaccine like this to ensure that vaccine coverage is optimised.”

Nuvaxovid is in ongoing phase 3 trials, one conducted in North America and one in the UK. A phase 2a/b study is also being conducted in South Africa. Healthcare professionals are asked to report any suspected adverse reactions.

The CMA given by the MHRA is valid in Great Britain only. Nuvaxovid is authorised in Northern Ireland under the CMA granted by the European Medicines Agency on December 20 2021. This CMA has similar requirements to that granted by the MHRA.

Créditos: Comité científico Covid

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