Rabu, 05 Agustus 2020

How scientists aim to make a safe COVID-19 vaccine in record time - CBC.ca

Vaccine development normally takes years, if not decades. But scientific teams around the world are aiming to develop a COVID-19 vaccine in 12 to 18 months.

Prof. Gary Kobinger is part of a team at Laval University that is trying to do that, and he thinks it can be done without skipping any steps in the process or compromising safety.

"I believe it's possible," said Kobinger, a professor of microbiology and infectious diseases who helped develop a vaccine for Ebola. "You just need to put the effort into it."

That, and, he acknowledged, "a lot of money."

But how? Here are some of the things that are being done differently during the development of a COVID-19 vaccine to speed up the process.

Flexible clinical trials

Normally, once it's been shown effective in preclinical animal trials, a vaccine needs to go through three stages of human clinical trials that are run one after another. They can take years to complete.

With COVID-19, vaccine developers are allowed to run trials in parallel. That is, Phase 2 can begin once early results from Phase 1 look promising, and so on, speeding up the process.

However, researchers note that each phase still must be run to its full length — typically six months for Phase 1, for example.

A patient receives a shot in the first-stage safety study clinical trial of a potential vaccine for COVID-19 at the Kaiser Permanente Washington Health Research Institute in Seattle on March 16. Many clinical trials for a COVID-19 vaccine are being sped up with 'adaptive design' and overlapping stages during the pandemic. (Ted S. Warren/The Canadian Press)

In addition, vaccine developers are allowed to do what's called adaptive design. They can create a plan to modify their trials depending on the results, said Lakshmi Krishnan, acting vice-president for life sciences at the National Research Council Canada.

For example if volunteers aren't responding to a low dose, you can give them a slightly different dose or a second dose — if that was in your plan.

"You cannot do this on the fly," Krishnan said. 

The adaptive design of Canadian trials needs to be approved by Health Canada, she said, and the department may request to see data more often in order to be able to approve — or not approve — further stages of the trial.

Advance manufacturing

Typically, doses of a vaccine aren't manufactured on a large scale until the vaccine has been approved. 

"Manufacturing is a laborious process and it can take many years to produce sufficient doses of vaccine," Krishnan said, noting that it's also the most expensive part of the process.

With COVID-19, in some cases, manufacturers such as AstraZeneca have announced the start of production in advance of approval during early phase clinical trials, with no guarantee that the vaccine would ever make it through the other phases and get approval.

"If the vaccine is a good candidate, we don't have to go back and do the manufacturing," Krishnan said. "We already have the doses available."

Prof. Gary Kobinger, who is part of a team at Laval University trying to develop a COVID-19 vaccine as quickly as possible, thinks it can be done in much less time than usual without skipping any steps in the process or compromising safety. (CBC News)

International co-operation and government financial support

Obviously, none of this would be possible without the financial support of governments around the world.

Normally, one of the reasons it takes so long to get through clinical trials is that scientists often have trouble getting the funding to move on to the next phase, said Dr. Natasha Crowcroft, director of the Centre for Vaccine Preventable Disease at the University of Toronto, in a June episode of CBC's The Dose podcast.

Pharmaceutical companies are reluctant to invest in a product that could fail at the next stage, and are often not sure there will be a market for a vaccine even if it does work, she said.

With COVID-19, governments are pouring money into vaccine trials and advance manufacturing, thereby assuming a lot of that risk.

Many are also co-operating internationally. For example, the COVAX coalition is a collaboration pooling money from dozens of countries around the world to jump-start advance manufacturing of several vaccine candidates, including some doses that would be set aside for developing countries.

Krishnan said international sharing of information as vaccine development progresses is also speeding things up: "You are leveraging the knowledge that is being generated in order to inform and accelerate your design."

Cells are counted through a microscope in the laboratory at Imperial College in London on July 30. The institution is one of more than a hundred teams around the world working on the development of a COVID-19 vaccine. (Kirsty Wigglesworth/The Associated Press)

Accelerated government approvals?

Kobinger says "the critical time" in COVID-19 vaccine development will be once the last stage of clinical trials has been completed and the data has been submitted to regulatory agencies, "because they will be under extreme pressure to make a decision. And of course, their main concern will be safety."

That stage can take years — four years in the case of the Ebola vaccine that Kobinger helped develop.

But he thinks the approval process can be compressed by increasing the number of staff in regulatory agencies involved in reviewing the data.

Governments can also use emergency orders to distribute vaccines prior to full approval in the case of an event such as a pandemic. For example, in 2009, Health Canada used an interim order to approve an H1N1 vaccine based on clinical trial data in Europe, even though clinical trials the Canadian version of the vaccine using the same adjuvant had only just started that same week in Canada.

In this April 11, 2020, photo released by Xinhua News Agency, staff members check and clean equipment at a vaccine production plant of SinoPharm in Beijing. In many cases, doses of COVID-19 vaccine candidates are being manufactured in large quantities before clinical trials are even complete. (Zhang Yuwei/Xinhua via AP)

Krishnan is confident that regulation for a new COVID-19 vaccine will be no less rigorous than usual.

"We can be assured that there will certainly be an oversight and that safety will be kept as the first consideration in any vaccine that is approved," she said. "So I think we have to trust that system."

Regulators will continue to monitor the safety of any of the vaccines as they're rolled out to the larger population after they're approved, she added.

While COVID-19 is a special emergency case, both Krishnan and Kobinger think what's being done now could speed up the development for future vaccines.

Krishnan noted that vaccine manufacturers, clinical trial investigators and governments are working hard together.

"Those alliances will hopefully set us up for the future to actually do these types of studies in an accelerated fashion."

Kobinger said up until now, we've relied heavily on old vaccines and vaccine technology.

"This is going to open a new era of vaccinations with safer vaccines, better vaccines and faster vaccines in terms of production," he added. "I think people will benefit for decades to come."

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2020-08-05 15:22:00Z
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