COVID-19 Vaccine Race a Balance of Safety and Speed

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Extraordinary cooperation and accommodations are needed in the race to build a COVID-19 vaccine from scratch while chasing a pandemic, said members of industry and government who convened for an update on the vaccine clinical trial process.

The message came from representatives from the Food and Drug Administration, a think tank, and the nonprofit sector who provided some insight into the vaccine development process for COVID-19 at a press briefing hosted by the Commonwealth Fund.

Even in the best of times, vaccine development is not simple, said Litjen (L.J.) Tan, PhD, chief strategy officer for the Immunization Action Coalition. Ordinarily, the process can take from 10 to 20 years and cost well over a billion dollars. Many vaccines wind up being abandoned before phase 3 development just because the cost is prohibitive, he said.

Vaccines undergo extensive ongoing postmarketing surveillance even after approval, licensing, and distribution, noted Dr. Tan, adding that the development of a safe, effective vaccine is a "very complicated, significant process."

In these extraordinary times, many adjustments to the usual trial trajectory are needed, agreed all participants. To speed the process, the traditional vaccine trajectory is being accelerated and compressed; changes may include simultaneous rather than sequential clinical trials that are run in parallel. These trials may be optimized for multiple target populations at the same time, and run in different countries, explained Dr. Tan.

"We are likely going to use something called adaptive trial designs" in which results are gathered during the trial and used to modify the trial according to prespecified rules, he said. "These trials shift to accommodate data as it comes up."

Regulatory agencies are actively engaging in the process much earlier than usual, with input including how to incentivize scaling up production of vaccines and ensuring that vaccines will be fairly and equitably distributed across the globe, he added.

Esther Krofah is the executive director of FasterCures, a center within the nonprofit Milken Institute. Currently 86 different active COVID-19 vaccine projects are underway, she said, with 6 currently in clinical trials and about two dozen more expected to enter the clinical trial phase by the summer of 2020.

Many of these projects will involve a smaller biotech company or an academic research group with deep knowledge of a particular immune strategy partnering with a large pharmaceutical company that has economic capacity and global resources and reach, said Ms. Krofah.

From a policy perspective, she said, it's important for the FDA to have surge capacity with "enough arms, legs, and staff to actively provide input into clinical design and protocols of studies." The goal is to be able to review data in real-time and provide rapid feedback as studies are occurring so adaptive clinical trial design can be implemented.

As COVID-19 vaccine trials are rolled out, necessary compromises may include incorporation of real world evidence in later clinical trial stages. "There is a way to do randomized trials in the real world in situations that come up like this," said Peter Marks, MD, the FDA's director of the Center for Biologics Evaluation and Research. Long-term data about vaccine efficacy may be accrued over time, once a vaccine is being administered beyond the clinical trial stage, to see if efficacy wanes over time.

However, he said, "a lot will depend on where the vaccine is and what we encounter with whether there's circulating virus or not" in terms of clinical trial design, including whether surrogate efficacy markers such as antibody production would be used.

Unvaccinated members of a population may be used as controls against a vaccinated group during an active outbreak, he said, a break from traditional trial design. "It's not perfect. I'll acknowledge right away there are certain people at the [National Institutes of Health] that would like to tell me that's a horrible idea, but I think we are going to entertain and discuss all potential designs" for COVID-19 vaccine trials, he said. "We can't out-of-hand dismiss any design here, whether real world based or evidence based."

"This may be a little unusual hearing this from the FDA," he said, "but this is possibly one of the most important things we are going to have to do in the next few years." He added, "It's unfortunately not unlikely that we will see a second wave, or maybe even a third wave, if we don't get it right."

He pointed out that there was no candidate vaccine in the pipeline when the pandemic blossomed and began its race around the globe. Current coronavirus candidates aren't useful against COVID-19. "We know that there might be some complexities in development" related to the contributions of immune enhancement to the pathogenicity of the SARS-CoV-2 virus, he said.

The agency is currently working closely with sponsors of various candidate vaccines to take a hard look at preclinical data and trial design.

"Low efficacy could distract from capacity for more robust candidates to come forward," he said. "We'd like to encourage people to have the absolute best vaccines… We hope to be able to facilitate rapid development of these," he said.

Moving forward, a whole-government approach is necessary for development and delivery of the best vaccine. Ms. Krofah elaborated that the FDA and the Centers for Medicare & Medicaid will need to collaborate closely as studies evolve. In particular, CMS needs to be ready with reimbursement codes, recognizing that both public and private payers will likely be providing reimbursement for COVID-19 vaccinations.

"When these vaccines get approved, we are going to have to decide who is going to pay for them," said Dr. Tan, who previously served as the director of medicine and public health at the American Medical Association. He noted that CPT coding comes through the AMA.

Dr. Marks stressed that ultimately, although treatments or prophylactic regimes against COVID-19 may be developed, "a vaccine is the most efficient way to protect large numbers of people." Though there's going to have to be a balancing act so speed doesn't come at the expense of vaccine safety and efficacy. "We are very much hoping that we can find vaccines that have relatively high levels of efficacy," he said, adding a hopeful point: "Right now there have not been mutations that have occurred ... that would alter vaccine development programs in terms of the targets they're going after."

Dr. Marks offered a wildly optimistic — and then a more realistic — judgment as to when a successful vaccine might emerge from the development, trial, and approval process. After acknowledging that the FDA might consider an Emergency Use Authorization (EUA) if coronavirus activity is high when a candidate vaccine emerges, he said that "if everything goes perfectly," an EUA for a vaccine might be issued within 9-12 months.

"The most likely timeline — and this is total speculation — is that it could be 12-18 months," he said.

Ms. Krofah concurred, adding, "We're seeing the big companies put a big bet on that timeline as well." She cited Johnson & Johnson, which has committed to a $1 billion COVID-19 vaccine development program by the end of 2021.

Finally, when a vaccine does become available, who is first in line to receive it? Ms. Krofah said that it will be important for the public to know that there will be a tiering scheme for vaccine administration in the early days. Healthcare workers, emergency responders, and the particularly vulnerable may be among the first to receive protection, she said.

Kari Oakes can be reached at koakes@mdedge.com. This article first appeared on MDedge.com.

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