how immunologist Sarah Gilbert outdid the others

© John Cairns / University of Oxford

The team led by Sarah Gilbert had an innovative prototype adaptable to a new virus. He joined forces with the AstraZeneca laboratory.

Confident, she did not procrastinate when her 21-year-old triplets, biochemistry students, wanted to receive two injections of her Covid-19 vaccine as part of UK trials. At 58, immunologist Sarah Gilbert, head of the Oxford University project, has long been preparing to respond to a global virus. On Monday, his “baby”, the result of British public research merging with Anglo-Swedish producer AstraZeneca, showed promising preliminary results. The researcher has been dedicated to experimental vaccines for more than twenty years.

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The ChAdOx vector

Since joining the Jenner Institute in 1994 – a team working on malaria and tuberculosis – Sarah Gilbert has created a group there dedicated to finding a universal antidote to the flu. In 2014 he conducted the first trial of an Ebola vaccine. The outbreak ended before the project was completed, but the team patented its ‘viral vector’ vaccine, a technology adaptable to a variety of pathogens. It uses a chimpanzee adenovirus (cold virus) rendered harmless as a vector to allow the introduction of genetic material into cells and generate an immune response. “This is their great contribution, summarizes the teaching of immunologist at Oxford Benoît Van den Eynde. It generates fewer neutralizing antibodies, therefore a stronger immune reaction”.

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To promote this vector called ChAdOx, the Jenner Institute created a start-up in Oxford, Vaccitech. Professor Gilbert and his colleague Teresa Lambe then used it to develop a vaccine against the Mers virus. The second human test was starting when Sars-Cov-2 appeared. This time the researchers reacted as soon as the coronavirus genome was published in January. The idea? It uses their ChAdOx with a protein gene on the coronavirus surface. “Over the weekend the vaccine was pretty much designed,” Teresa Lambe told the BBC. Mouse tests are launched in mid-February. Oxford, which has a small manufacturing facility, is rolling out a batch for human testing as it plots an industrialization plan. “They had worked a lot on the seas, a very close virus, continues Benoît Van den Eynde. They had the vector, the technology, the experience …”

Goal: three billion doses in 2021

It remains to start production. Support comes from patrons such as Cepi (a coalition initiated by the Gates Foundation), Norway, India; then the British government (2.2 million pounds, or 2.5 million euros), which pre-orders 100 million doses. In early April, the vaccine was injected into 1,100 volunteers. For production, the team contacts several pharmaceutical groups. Sarah Gilbert wants a product “for the whole world”. It was with AstraZeneca, Big Pharma but modest vaccine actor, that an agreement was concluded in ten days, accompanied by an unprecedented announcement: during the epidemic a dose will be sold for 2.50 euros, and this cost price will be maintained for low-income countries. “We are a university and we are not here to make money,” the vaccinologist told al BBC.

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We are a university and we are not here to make money

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The Oxford prototype has one advantage: it can be stored in the refrigerator. This “simplicity of the supply chain” and AstraZeneca’s “non-profit” commitment, believes its CEO, will make it “accessible and available worldwide”. The company aims to produce 3 billion doses in 2021. If the British pharmaceutical authorities, which evaluate the safety of the vaccine, give the green light to its marketing, 4 million will be delivered in the UK by the end of 2020, and 40 million ‘ here March. With an average efficiency of 70%, according to preliminary results, it seems less efficient than those of Pfizer-BioNTech and Moderna (95%). But it jumped to 90% when the volunteers first received half a dose and then a full dose. The team is conducting a further study on this unexpected effect. Didn’t Pasteur say that “luck only favors well-prepared minds”?