Preparing for COVID-19 vaccine success
The next steps for COVID-19 vaccines, a BioCentury/Biokatalyst webinar
The European Commission and international organizations are working to create a purchasing pool for global allocation of COVID-19 vaccines, according to Nicole Lurie, strategic adviser to the CEO of CEPI.
Lurie discussed the purchasing pool on a webinar about COVID-19 vaccine development co-hosted by BioCentury and BioKatalyst in collaboration with Lonza Group Ltd. (SIX:LONN). The webinar also included an update on a COVID-19 vaccine from CanSino Biologics Inc. (HKEX:6185), Lonza’s plans for manufacturing an RNA vaccine from Moderna Inc. (NASDAQ:MRNA), and perspective from Vaccitech Ltd. on the AZD1222 (formerly ChAdOx1 nCoV-19) vaccine that AstraZeneca plc (LSE:AZN; NYSE:AZN) licensed from the University of Oxford.
Lurie, who served as Assistant Secretary for Preparedness and Response at the U.S. Department of Health and Human Services (HHS) during the Obama administration, said that national leaders have responsibilities to take care of their populations. She added that “all the modeling is really clear that the best way to have economic recovery around the world, including in the US., is probably to vaccinate all frontline workers around the world, rather than vaccinating all people in any one country.”
In that context, the U.S. government must “consider how it wants to balance the needs for its own population with some of the more global needs,” Lurie said. “It hasn’t tipped its hand yet.”
Unlike the U.S. or other national governments, the Coalition for Epidemic Preparedness Innovations (CEPI), which has emerged as one of the key funders of COVID-19 vaccine development, views its mission as including equitable global access.
Lurie reported that “there is a lot of planning around a purchasing pool of some kind or another through which GAVI and potentially others would be able to make some kind of an advanced commitment to procure doses from vaccine manufacturers that were successful at producing a safe and effective vaccine, with the idea that there would then be an allocation system across countries.”
The purchasing pool could be announced in conjunction with a June 4 GAVI pledging event, Lurie said.
Lurie also discussed the importance of building trust in vaccines, and called for governments to “shut down the foreign bots that are spreading misinformation about vaccines around the world.”
Trust and vaccine disinformation have emerged as serious concerns that are not being systematically addressed (see “The Missing Dimension in COVID-19 Vaccine Development”).
In addition to discussing policy, Xuefeng Yu, chairman, CEO and co-founder of CanSino, presented an update on the webinar about the Ad5-nCoV vaccine. CanSino has completed a Phase I study and was the first company to launch a Phase II COVID-19 vaccine study (see “Making Sense of the Deluge of Early COVID-19 Vaccine Data”).
Yu discussed concerns raised by the Phase I data that pre-existing antibodies to the vaccine’s Ad5 vector muted T cell responses to the vaccine.
“Ad5 is a common virus circulating in humans and it does raise concerns about pre-existing immunity,” Yu said. He added, however, that “when we look at the historic data, either from MERS trials data or from our own Ebola vaccine, [while] there is impact on pre-existing immunity and the vaccine immunogenicity for the antigens, our experience is if we give sufficient amount of viral particles certainly we can reach an acceptable immune response level.”
Yu added that CanSino’s experience with an Ebola vaccine demonstrates that a second dose of an Ad5 vaccine can boost efficacy. “That’s why we’re designing a two-dose regime clinical Phase I/II trial in Canada. Hopefully those trials will give us more options to see how we can further stimulate the immune system to have a better immune response.”
A lot of unknowns
Bill Enright, CEO of Vaccitech, discussed a different viral vector COVID-19 vaccine candidate, AZD1222, which was co-developed by Vaccitech and the Jenner Institute at Oxford University.
He noted that Vaccitech no longer has control over the clinical development of AZD1222 following its out-licensure to AstraZeneca.
Pre-existing antibodies are unlikely to reduce the efficacy of AZD1222 because it is based on a chimpanzee virus that humans aren’t usually exposed to, Enright said.
While the data obtained so far are positive, Enright noted that all COVID-19 vaccine developers are grappling with a great deal of scientific uncertainty. Unknowns include correlates of protection, duration of immunity, and whether protection will result from “binding antibodies to certain regions, or neutralizing antibodies, or T cells, or how much T cells will be involved in the solution.”
“The pandemic has highlighted three key challenges from the manufacturing perspective,” said Pierre Catignol, head of the Portsmouth, N.H., site where Lonza will manufacture Moderna’s RNA-based COVID-19 vaccine candidate (see “Lonza to Manufacture Moderna COVID-19 Vaccine”).
The first challenge stems from the variety of technologies used to produce the over 100 COVID-19 vaccine candidates under development around the world, he said. “A new technology like RNA can be a game-changer in vaccine development and supply,” but it has never been manufactured at commercial scale.
The second challenge is the long lead time required to build vaccine manufacturing capacity. “Building a facility from scratch can take four or five years,” Catignol told BioCentury, and it can take an additional 18 months to obtain regulatory approvals. This means it is necessary to invest in manufacturing capacity before a pandemic strikes.
The third challenge, Catignol said, is geography. COVID-19 has highlighted the need for distributed manufacturing for two reasons: the need for diverse supply chains and politics. Politics comes into play because the “potential for seizure by states” creates requirements to manufacture vaccines in different locations.