The case for a COVID-19 human challenge: An interview with VBI Vaccines CEO Jeff Baxter

Administering a trial vaccine on 400-500 people and then exposing them to COVID-19 would present obstacles and ethical questions, Baxter said, but it could accelerate the process enough that he would be willing to participate as a patient.

Tom Sullivan | September 2, 2020

Jeff Baxter and VBI Vaccines are on a quest to develop a pan-coronavirus vaccine not just for COVID-19 but also MERS and other SARS. In fact, last week two of VBI’s coronavirus vaccine candidates were selected to move into human clinical trials.  

Baxter, VBI Vaccines President and Chief Executive Officer, has been with the company since 2009. Prior to that, he was a managing partner for The Column Group, a venture capital firm, and served as Senior Vice President of Research and Development at GlaxoSmithKline.  

Health Evolution Editor-in-Chief Tom Sullivan spoke with Baxter about why he’s encouraged by vaccine developments thus far, the status of VBIs pan-coronavirus trials, reasons he would advocate for a human challenge to drive faster development timelines, and the need for societal healing.  

Health Evolution: When COVID-19 arrived in America, most predictions suggested that vaccine development would require 18-24 months. Now, six months later are you encouraged? Discouraged? What is your outlook for timing?   

Baxter: I am much more encouraged. The advances by Pfizer, BioNTech, Moderna, Novavax, I absolutely believe those will be effective and approved for first line responders and people at risk. And I believe those high priority people should be vaccinated by the end of next year. I am very hopeful that at least 4-5 fast moving vaccines will be approved in the second and third quarters of next year. That will be essential to protecting front line workers. Then in mid-2021-2022, I hope we have other vaccines particularly for elderly people. By the end of 2022, a dozen or so vaccines should be available such that people can go to CVS to select a vaccine that is right for that individual.    

Health Evolution: Where do the VBI vaccine candidates that were selected for human trials fit into the picture?  

Baxter: We certainly believe we have the potential to be a single dose vaccine that is stronger and more effective than some of the others that take two doses. Icould be a oneshot vaccine for people 45 and younger, and maybe 3 doses in those 45 and older. The higher level of immunity you start with the betterSo our study will last 6 months, taking us through to the middle of next year 

Health Evolution: What are the most substantive differences between VBIs trial vaccines and the others currently in development?  

Baxter: While everyone has been blown away by the warp speed of development, many vaccines require doses of 20-30 micrograms and some are at 100 micrograms. Ours at one dose provides higher protective antibodies with 2-5 micrograms, so you can produce 20x more vaccine than one that is 100 micrograms. That matters because the first priority in the U.S. will be the 10 million first line responders, which will require 20 million 100 microgram doses. After first line responders, the priority is the 100 million people at risk for comorbidities, another 200 million doses. Then there are 200 million more Americans that still need to be vaccinated. If you look at humanity, while the situation is severe in the U.S., the human aspect is everywhere. India now has a record number of infections, for instance. So it means a lot for humanity to be able to produce vaccines at scale, at lower costs, and in local areas. Ours is a ubiquitous manufacturing process that can be performed in China, Brazil, elsewhere. We are talking with partners about doing that.  

Health Evolution: What comes next? How do you envision this testing proceeding and when might we be close to a vaccine?   

Baxter: It depends on how aggressive or ambitious the regulators want to be for phase 3. At the moment, they’re sticking with 30,000 people to prove prevention of disease. That depends on enough circulating COVID-19 infections to prove that the subjects are protected, but there is emerging data from all of these trials that that there is a level of neutralizing antibodies that your body can produce to protect you — that means the trial could go faster.   

Health Evolution: How would that work? What would make the trial go faster?  

Baxter: We have just completed a 4,000-subject trial for prevention of Hepatitis B and for that one the level of protection is already known and understood – so the FDA requires 4,000 subjects in the database. If we could establish the same parameters for the coronavirus vaccine, we could start a phase 3 trial in the middle of next year. There’s also a more aggressive, human challenge study. You enroll 400-500 volunteers, vaccinate them and then expose them to the virus 

The human challenge is very much the best kind of animal challenge you can do. Now, would I personally push to move forward with a trial like this to the industry? Yes, and I would volunteer. I absolutely would.

Jeff Baxter, VBI Vaccines

Health Evolution: We should discuss the human challenge because the model can be controversial and raise ethical questions. First though, what’s the upside?  

Baxter: The human challenge is very much the best kind of animal challenge you can do. That sounds crude but it’s a fact. Its what we do with mice, hamsters. There are some human challenge studies already approved for flu, RSV (Respiratory Syncytial Virus), and some kinds of allergies. 

Health Evolution: But what are the associated obstacles? 

Baxter: You need to make sure you have a therapeutic so that should someone become infected you can rescue them, a rescue medication. If we had even thought of this six months ago, no one would have talked to you about it. It depends on having the right facility, beds, rescue medication and going into the study having proven efficacy from phase 1, phase 2.  

Health Evolution: The subsequent question, of course, is do we have one or more adequate rescue medications?  

Baxter: That has come a long way in the last 6 months. Last week, the FDA issued Emergency Use Authorization for convalescent plasma. Still, we have to think about younger and older subjects. Would you put a 75year old into this study or someone with asthma, COPD or cardiovascular risk? Absolutely notThese would be fit, healthy, 45 and under, a BMI of less than 30 and you would make sure its done in a facility. There are plenty such facilities with the right beds and necessary medication on hand in North America. We have to keep them under close observation for 2 weekspossibly in the facility or close so if they develop a fever they can come in quickly.  

Health Evolution: Returning to ethical issues, would you as the CEO of a company making vaccines feel entirely comfortable that the facilities, rescue medications, and so forth are available adequately enough to undertake such a study?  

Baxter: All studies have to be approved by an ethical committee, that can be the FDA or Health Canada. That would be a very extreme review. Now, would I personally push to move forward with a trial like this to the industry? Yes, and I would volunteer. I absolutely would. I’m 59, I believe I’m fit enough and this is the type of study that could radically accelerate the time it takes to earn approval for a vaccine. When you need 30,000 participants, it takes 4-5 months just to enroll them and vaccinate, then at least 6 or 12 months from there.  

Health Evolution: Given the risk and what we do not yet fully understand about COVID-19, what is the likelihood of enough people enrolling?  

Baxter: has been pushing hard for the concept of challenge study. It already has 35,000 volunteers. It started in the UK, spread quickly to the USCanada and Northern Europe 

Health Evolution: You suggested in response to the first question that by the end of 2022 there should be a dozen vaccines available such that people could walk into CVS and select one. Is that when we reach the point of herd immunity? Or would we already be there and that’s more akin to an annual flu shot?  

Baxter: What you have to remember with herd immunity against a virus is that we need 60%-70% of the global population to be immune to get back to the types of mobility we used to have. We also have to bear in mind the forced mobility though refugees and other humanitarian crises, the explosion in Europe that’s being caused by Syria, Ethiopia because they arrive unvaccinated. It’s similar in the U.S. Until a vaccine is readily available at large scale and acceptable cost, that will continue to cause problems we need to address.  

Another problem. I saw a recent survey by Evercore ISI of more than 1,000 biopharma professionals and investors, which determined that despite 90 percent of participants expecting a COVID-19 vaccine to be effective, only 30 percent indicated they would get a shot within three months of initial availability, 40 percent opted to wait six months to a year and another 30 percent answered that they intend to wait a year or more.  

Health Evolution: As the CEO of a company working on a vaccine, what would you say to those people who prefer to wait? 

Baxter: Have faith in the FDA. If there is going to be a safety signal with a vaccine you will know about it in the first 3 months. It may be that some of these first vaccines to be approved are not the most effective. When the HPV vaccine was developed, those girls were followed for 10-15 years. Wdon’t have that luxury nowAnd the people we need to get mobile again for the economy is the 45-60-year olds who go to restaurants, spend money in the community, buy things for the grandkids — I’m not talking about economic recovery, we need societal recovery, people need to be working again as soon as it’s safe.   

About the Author

Tom Sullivan, EVP & Editor-in-Chief of Digital Content

Tom Sullivan brings more than two decades in editing and journalism experience to Health Evolution. Sullivan most recently served as Editor-in-Chief at HIMSS, leading Healthcare IT News, Health Finance, MobiHealthNews. Prior to HIMSS Media, Sullivan was News Editor of IDG’s InfoWorld, directing a dozen reporters’ coverage for the weekly print publication and daily website. Contact: or @SullyHIT on Twitter.