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A Q&A on coronavirus vaccines

A line of syringes, representing potential vaccines

Since the outbreak of the coronavirus pandemic, Dr. Karen DeSalvo, Google Health’s chief health officer, has been a trusted source for learning about its impact and implications. She's advised Google teams on everything from how to respond to the pandemic in our own workplaces, to how we can build products and features that help everyone navigate COVID-19, such as the COVID-19 layer in Maps. Recently, we shared an update on how we’re doing just that, as well as helping businesses around the world get back up and running.

With lots of discussion worldwide about COVID-19 vaccines, today we published for our employees an interview with Dr. Karen about this topic. We’re sharing a version of that interview more broadly in case it’s helpful or informative for others to read.

As the former director of the United States’ national vaccine program, Dr. Karen is intimately familiar with the subject of vaccines. In this interview, she tells us more about what happens in a vaccine trial, when we can expect to have access to one and what it takes to vaccinate the entire world’s population in record time—a feat the human race has never before undertaken.

Let’s start with the basics. How are vaccines created? 

It’s a rigorous scientific process. It typically involves starting with a concept in animal models to understand if we can identify proteins on an infectious agent, and then simulating a body’s immune system to create a response. Vaccines move through a series of defined phases to test their safety and efficacy in humans. These trials are very large and involve thousands of subjects, and the results lead to a regulatory process that will differ country to country. Then comes the approval process, and then they’re manufactured and deployed.

It sounds like it could take years for all of that to happen. 

For COVID, some of these steps are happening in parallel rather than serially. We’re already manufacturing vaccines that have not yet finished their clinical trials. If they don’t meet the bar for safety and efficacy, they will be disposed of. Deployment of the first generation of approved vaccines will have some challenges. They will require special cold storage at all times, including in transit and warehousing, at -73 degrees Fahrenheit. This may mean they will only be available at specialized centers that have that kind of freezer system. But over time, it’s expected that they will become easier to deploy and administer.

For those of us who haven’t been following every detail in the news, when can we expect to have a COVID-19 vaccine available?

Based upon the pace of science, we’re anticipating that in the U.S. there will be an approved vaccine this winter, and very near that for other parts of the world. More than 200 vaccines are in development, and more than 40 are in human trials. There are two leading candidates in the U.S.—one of them made by Pfizer, and one by Moderna. Pfizer just released some preliminary data this week; they will still need to go through the formal scientific and regulatory review with final results. Other vaccines people should be paying attention to are the AstraZeneca/Oxford vaccine, based in the U.K., and one made by Johnson & Johnson. But there is a lot of exciting science in this area, and the New York Times keeps a great tracker.

You’ve said before that once a vaccine is available, though, it will not be like flipping a switch. 

It will take years to get the world vaccinated. This has never been done before at the pace we are attempting. There will be different “generations” and types of COVID vaccines as the science evolves. They all come with their own special characteristics and may target special populations. Those which come out early will likely require two doses, and it will take six weeks until you build sufficient immunity. Another important point: The conventional wisdom is that more advanced vaccines are expected to reduce symptoms and spread, but not fully prevent or eliminate disease. The vaccines in the current pipeline are designed to prevent disease rather than prevent infection; it’s more like the influenza vaccine—you might still get it, but it will be a less serious case. This means that in reality, we will all have to integrate vaccines as another layer into our public health hygiene, like masking and social distancing.

Who’s participating in vaccine trials right now? 

People around the world have been enthusiastically signing up to participate. My husband is one of them! When he got a call from our local health care system, he marched himself over there and enrolled in the trial. He’s an ER doctor, and he’ll want to get vaccinated because of his ongoing exposure to COVID patients. The trials are randomized, controlled and double-blind: when he got his shot, the nurse turned her head so she couldn’t see what it looked like, and he couldn’t look, either. You sign up through a website, and if you’re eligible, you get a call. Generally, people have to be 18 or older to participate as a volunteer, but the studies are looking for volunteers of all backgrounds and identities.

It wasn’t too long ago that we learned that a late-stage clinical trial for a vaccine was paused due to an “unexplained illness” in a volunteer. Can you tell us what that means? 

When there is any kind of abnormal event, the trial Data Safety and Monitoring Board gets a chance to pause and make sure it isn’t a consequence of the drug. So, a pause like that one means good news; it shows the scientific process is working. There have now been two phase-three clinical trials that have been paused due to a potential event. Both have resumed. Don’t be surprised if it happens again. But there’s nothing so far that indicates there’s a problem with these vaccines. People enrolled in trials will still have the normal life course of health events. I know firsthand that the scientists who work on this are extraordinarily ethical, highly capable and really hard workers.

Lastly, the question that’s on everyone’s mind: Does any of this give us a clearer sense of when we might be able to get these vaccines ourselves? 

If everything continues to roll out the way we think it will, the general population would begin having access to a COVID vaccine by late spring or early summer 2021. That’s pending the manufacturing, that we have enough supplies like medical glass and dry ice, and that we’ve figured out how to manage the cold chain expectations. We should all be encouraged by the degree of global cooperation, including the focus on ensuring low- and middle-income countries and communities have access.

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