Biological E’s vaccine candidate works well to control Sars-Cov-2 variants of concerns, and work has already begun to make alterations in case more resistant mutations occur, according to one of the leading scientists who is part of the development team. In an interview with HT, Maria Elena Bottazzi, the associate dean of Baylor College of Medicine’s National School of Tropical Medicine, said Biological E’s recombinant DNA vaccine could address a large gap in global supplies in general, and help inoculate children in particular, and spoke of the need to ensure second doses are given on time to reduce the risk of mutations. The Baylor College of Medicine has partnered with Biological E for the vaccine. Edited excerpts:
Tell us a little bit about the progress of the Biological E vaccine.In 2020, we transferred to Biological E the seed stock to produce this recombinant protein Covid-19 vaccine candidate. Biological E have been doing a number of things since: they are advancing the manufacturing, and are also maturing the process and scaling it up. They are testing the manufacturing stock, and at the same time, have engaged in a clinical development plan. The company has got the approval to initiate a large Phase 2/3 trials in India, while in parallel, it’s also working with global agencies, including CEPI (Coalition for Epidemic Preparedness Innovations) to launch a global clinical trial.
When can we expect to see the results from the Phase 1/2 trial? I think they’re (Biological E researchers) finishing up compiling all the data from the Phase 1/2 stages and the company will probably provide more information soon. They have already received the approval for Phase 3 trials so you will probably see that they’re going to be launching that in the next week.
Have you been able to test how the vaccine works with the variants of concern we have at the moment? Yes, in our laboratories, working in partnership with Biological E, we have evaluated the performance of the vaccine using our pseudovirus technique, and clearly, the vaccine induces cross neutralising antibodies against the different variants, including B.1.617 (Delta) variant. We are also re-engineering the vaccine candidate and have already transitioned to Biological E additional constructs for them to evaluate – to see if we will in the future need boosters or a second generation dose against the different variants. But the vaccine that they are currently advancing is quite cross-protective and performs well against variants of concern. At the same time, we’re looking for alternatives in case in the future, we need to redesign the vaccine. So, it is a two-pronged approach.
We have constructs for Sars, and for Mers, and now we have a toolbox of different constructs against Covid-19, so we’re looking at ways to develop second- and then third-generation vaccine candidates.
You mentioned in the past that this vaccine could show particular promise for use among children. Can you tell us a little more about that? The yeast expression technology (the platform used) is the mainstay for a lot of vaccines -- it’s the same process used for the Hepatitis B vaccine, which is widely used in paediatric population. There is a lot of experience in quality production, and regulators are quite abreast of the safety. And because it’s a system used for other licensed vaccines, it’s also reassuring. After authorisation (for adults), Biological E will start looking at evaluation in paediatric populations.
There is a debate over whether second doses of the vaccine should be delayed, as has been done by India, particularly in light of the reduced efficacy with the Delta variant. What is your opinion on it? That is a hard choice because we know that you really require the two-dose scheme to ensure you maximise the immune response, but at the same time, you don’t have enough vaccines to cover as many people as possible. I appreciate the stress of wanting to make sure a lot of people start getting vaccinated, but if you start vaccinating people that are not fully protected, that may also open the window for this virus to continue mutating and enabling it to escape immunity. Scientifically, we favour that individuals stay within the schedule of that vaccine.
From what we have seen of the Sars-Cov-2’s evolution till now, how do you see the pandemic evolving and how does it pose a challenge to the vaccination programme? If we continue to have this very patchy world, where there are areas where you’re doing a really good job in access and distribution of vaccines but in other areas you don’t, I think there’s going to be more of this emergence of variants of concern. It is most likely going to require all of us get a booster shot sometime late this year or early next year. And this is, again, another reason why we now first need to ensure we have enough vaccines to catch up areas where there is still a lag in coverage. At the same time, we will also need to have availability to fill gaps for other ages, including the paediatric population. So, as you can see, that’s the real urgency of continuing to ramp up production, ensuring there’s enough supply of all the reagents you need, and to have a very good ecosystem in the health system for distributed storage. And then, ultimately, you need a high level of confidence so that people use the vaccines.