A reference in the area, he stressed that the candidates must show results before being used outside of clinical trials.
Sarah Gilbert has spent 15 years developing vaccines against influenza (the flu virus) and other emerging pathogens, including MERS, a member of the coronavirus family, which emerged in 2012. That is why, when SARS- CoV-2 began to spread, had part of the task ahead. Under his leadership, a team from the Jenner Institute, Oxford University, as soon as the genetic sequence of the new virus was known, began working on a development that could protect against infection. Thus arose what is known today as “Oxford and AstraZeneca vaccine”, by the pharmaceutical company with which an agreement was sealed for the global manufacture and distribution of the potential vaccine.
AZD1222 is made from a chimpanzee adenovirus (ChAdOx1), to which genetic material has been added so that it can produce the Spike protein (found on the surface of the coronavirus) after vaccination and thus prepare the immune system for recognize and attack SARS-CoV-2. It uses the same technology as a vaccine that Gilbert’s team had developed for MERS and that had shown safety in animal models, allowing them to chop pointed.
Currently, it is one of the most advanced: phase III studies of studies – the last instance before authorization and commercialization – that are carried out in Brazil, South Africa, Great Britain and the United States are already well advanced . In Argentina, through an agreement signed with AstraZeneca, the biotechnology company mAbxience agreed to the transfer of technology to produce the active substance necessary to manufacture 250 million doses of the vaccineIf it is proven to be effective and safe, it will be distributed in Latin American countries, except Brazil.
Gilbert is a biologist, Ph.D. in biochemistry, and Professor of Vaccination at the University of Oxford. She will be the main speaker of the 7th edition of Bioargentina, where together with Per Alfredsson, Senior Vice President of Global Biological Operations of AstraZeneca, they will give details of the open innovation model between academia and industry that they lead for the development of the vaccine against Covid-19. Before her presentation, the researcher responded by email to inquiries sent by Clarion.
-Will the results of phase 3 of ChAdOx1-S (today called AZD1222) be known before the end of the year? What information will they provide regarding safety and efficacy?
-Ours is one of several vaccines that may have efficacy results in the coming months, if transmission rates remain high. I was confident that we would see a good immune response to our vaccine, based on the work we had already done on a MERS vaccine, and that turned out to be correct. We will need a longer follow-up to see how durable the immune responses are.
– Can a vaccine that shows immunogenicity (development of antibodies) not be effective in preventing or reducing the disease burden?
-No one knows yet how strong the antibody response must be to protect against infection or reduce the severity of the disease. This is why we need phase III trials to show efficacy data.
-What do you think about early or limited approvals (as Russia and China have carried out)? In the emergency setting: How do you assess the risk / benefit of starting vaccinations without the results of phase 3 clinical trials?
-I think we should find out if the vaccine is effective before we start using it outside of clinical trials.
-There are several vaccines based on adenovirus platforms, but yours is based on a chimpanzee adenovirus. Does it provide any benefit over the others?
-Since people do not have antibodies that can bind to the adenoviral vector, it can work well in more people.
-Do you consider that the accelerated development process of anti-Covid-19 vaccines will contribute to reinforcing confidence in vaccines or will favor rejection?
-It is important to understand that vaccines that have been developed rapidly are using technologies designed specifically for that purpose, and a lot of work has already been done. We were working with vectorized ChAdOx1 vaccines in clinical trials many years before this current pandemic.
None of the safety testing has been overlooked, but we’ve accelerated vaccine development with processes such as ongoing data reviews and help from regulators. In most vaccine programs, a lot of time is spent on fundraising, and this time it was very different.
-The FDA has warned manufacturers that they would want to see proof that vaccines can protect at least 50% of those who receive them. Can you estimate how effective the Oxford vaccine will be?