The latest limit imposed by the US Food and Drug Administration on the coronavirus booster shot took many by surprise, including Dr. Tal Zaks, an Israeli researcher living in the United States, who was in charge of Moderna's vaccine development.
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"Yes, I was surprised," he told Israel Hayom. "I think the refusal stemmed from the way the question was posed. But the fact is, the ruling to administer the shot to people over 65 and those at high risk passed unanimously, and in my opinion, it is only a matter of time until the recommendation is expanded."
Q: In your opinion, is the booster shot effective?
"Yes, data from Israel is clear and it shows that immunity [provided by the third shot] is significantly high."
Q: Do you think the FDA ruling should affect the booster campaign in Israel?
"I don't think so."
A few months ago, after serving as a chief medical officer at Moderna – which began as a humble startup and turned into a global vaccine manufacturer – Zaks decided to leave the company and look for a new challenge. Most recently, he was offered a job at Teva Pharmaceuticals, Israel's largest drug producer.
"My role at Moderna began to change in early 2020 when I enlisted in the battle against the coronavirus," Zaks said from his home in Newton, Massachusetts. "Toward the end, it was clear to me and to the CEO [Stephane Bancel] that I had achieved what I wanted, and that the position of the medical officer has essentially become like that of a minister or ambassador, ensuring the safety of the platform and traveling the world explaining what it does.
"I learned the importance of communicating with the public and the press, but what motivates me is the scientific endeavor, so for me moving on felt like the natural next step. At the end of the day, the feeling is that the great war [on COVID] is coming to an end. Here and there, additional battles continue, but [for me] it is time to return home, back to civilian life."

Q: What are your plans now?
"I would like to get into places where I could develop innovative medical technologies and make them accessible, similar to the mRNA platform [that Moderna developed, which is transforming the world of medicine and vaccines. I would like to spend a year or two looking into discoveries I believe are interesting, the ones that could potentially help patients and entire populations.
"Another thing I wanted to do is contribute more to the Israeli biotechnology ecosystem, and so I was delighted when I was offered a place in Teva's directorate. It gives me a channel to be involved, I hope constructively. I will continue to live in the States, but will travel to Israel more often."
Q: Do you have aspirations to become the coronavirus commissioner in Israel?
"No. It is a position that requires expertise in public health, whereas I have experience in developing drugs and vaccines, not distributing them to the public."
Q: The break you are taking in between jobs, I assume, is also possible due to your success at Moderna.
"Sure. What enabled me to take some time off is that for the first time in my life paychecks are less crucial when it comes to supporting my family. Although, the financial aspect was never the one that motivated me. My family and I arrived in the US with nothing, and it went on like that for many years.
"When you have complete financial freedom, it changes your perspective and makes you think about what it is you would like to do. On paper, my life has changed, but practically speaking, I do not know what to do with this. Part of the luxury is to take a break in order to brainstorm what to do next. Never in my life have I taken more than 3 or 4 weeks off, and the last time I did it was in 2008.
"My lifestyle has not changed. When we came on a visit to Israel in the spring, I had to convince my wife to fly back in economy plus, as opposed to just economy, with five more inches of legroom."
Zaks, 55, started working at Moderna in 2015.
Q: Do you miss the old days when Moderna was a small company?
"Yes, that is what I meant that the size [of the company] defines the position, and I used to love the position I had. But it no longer exists, not in the same format.
"At the beginning of my career at Moderna, nobody received mRNA Moderna vaccines, not in clinical trials and surely not in actual patients. During my time, we started clinical trials with the new technology, and we conducted more such trials than ever before in the history of biotechnology. If you look at the number of clinical trials [conducted] while I was there – considering the age of the company – we broke several records.
"Before I joined, I remember I spoke with the CEO and told him, 'Why are you hiring me? I am an oncologist, and you need someone with experience in developing vaccines.' And he said, 'We want to cover all fronts with this technology. We will try to develop vaccines against cancer and vascular diseases and rare illnesses.'
"He was looking for someone with a broad vision who could do a variety of things. No one among developers has experience in all areas, so for me, the challenge was to oversee something that is beyond my experience, and it was a lot of fun."
mRNA molecules are a segment of DNA that includes instructions for the production of a particular protein. In the case of COVID-19, that protein is called Spike. The laboratory creates the mRNA with a code to make copies of an antigen (the molecule in the virus that triggers an immune response in the body and creates antibodies). When this code is injected into the body, the cell produces only the antigen, without the virus or anything else that could cause disease. Thus, if the immune system encounters the antigen in the future, it will know to recognize and fight it.

Q: Was the race to develop a COVID-19 vaccine like a madhouse?
"Not a madhouse, but incredibly challenging. I served in the IDF, started in combat engineering, and then became a paramedic and medic instructor. My whole life I've avoided using military analogies, but last year I caught myself using for the first time phrases like "enlist in the mission." For there is no other way to describe it. How we worked day and night, had a headquarters and a command, and in essence, this was a war, but without an actual army or engaging in physical battle."
Q: Did you feel the heavy responsibility of developing a vaccine for all of humankind?
"Yes. Throughout my career, I mainly developed drugs, and as an oncologist, this was mostly medicine for cancer patients. In those cases, I imagined in my mind the patient who would be affected, and here and there, I would hear stories about actual patients who benefitted from the drugs.
"With COVID, it became personal in a way that no drug developer has ever experienced [before]. And I mean, my mom, who is 80 years old, and lives in Israel. My daughter-in-law, a doctor in New York who now had to wear protective gear, and all the wards in the heart of Manhattan became intensive care units.
"You just know that you are developing something that will protect your family, we go out to battle and know exactly what we are protecting. For each and every one of us, it was personal and close to heart. That is why the coronavirus was different from how we usually operate."
Q: When did you feel like you succeeded in overcoming the virus?
"The fact that the front changed was clear already in May 2020, when we saw the results of the first phase of trials. The absolute victory, or the decisive battle, was after the third phase when the final results came in. Pfizer's first, then a week later ours. It was clear that we had won the war, and from then, it was just a matter of time."

Q: Did you feel like you were in a race with Pfizer to be the first to develop the inoculation?
"No. I said to myself, 'I only have two rivals – the virus and the ticking clock, and to everyone else I wish victory.' Of course, some in the company did take into account the financial aspect and the future, and how we will perform compared to global giants, and they added a competitive element. As long as the pandemic continues and the world needs the products of two companies, and even more, I care less about the competition."
Q: For Pfizer, as the world's biggest vaccine manufacturer, the race was important.
"No doubt. Many people forget, but Pfizer did not come up with the coronavirus or the mRNA vaccines. It purchased the German BioNTech company and together with it, raced to develop. Moderna, on the other hand, created the vaccine from scratch.
"BioNTech and Pfizer would not have the coronavirus vaccines today had Moderna not started the race for vaccines against other diseases. After all, the collaboration between them began about three years ago, when they made an agreement to tackle the flu.
"A collaboration that came about because they saw Moderna develop vaccine after vaccine after vaccine. BioNTech was [originally] established to fight cancer, it did not deal with infectious diseases at all."
Q: So Moderna deserves some of the credit too?
"I see how much disease and mortality have been prevented in the world, and that is credit enough."
The coronavirus truly put Moderna on the map. If in May 2020 the company's value was estimated at $30 billion, then by the summer of 2021, it increased six-fold, to $185 billion.
Q: Is a pandemic a good thing for a drug company?
"Paradoxically, yes, because it allows the company to find its place in the world. Moderna before the pandemic and after are two different companies. COVID allowed the company to prove what it can do for humankind."
Q: And earn billions.
"The company makes a profit because we operate according to a capitalist model. And thank God that it is like that because if you have the choice to develop vaccines for profit or under a communist regime, which one would you choose?
"Maybe I've lived too many years in the world, but for me, it's not a paradox. On the contrary, I think all of the beauty lies in this. As a doctor in the industry, it may have been my life's biggest personal challenge, to combine financial interest with the greater good, and benefitting the public gives me a tremendous sense of fulfillment. We help people and at the same time, prove to our investors that their investments can yield returns. Win-win."
Q: What was the most important part for you in the race to develop the vaccine? The knowledge that you contributed?
"I think both for me and the company, it was the ability to move fast and make decisions, look at data and respond, which was more important than the knowledge. Because no one else before had to deal with what he had to. There was one week, at the end of May in 2020 when we had to make a decision [about vaccine dosage].
"After all, we had informed the world that the first phase of the vaccine trials was successful, and had to finalize the protocol for the third phase, so that we could start the proceedings in July with the relevant government institutions. We had to decide on the right vaccine dosage to be given in the third stage of the trial – 50 or 100 micrograms.
"Expertise-wise, it was one of the hardest decisions I ever had to make. If 50 micrograms were enough, perhaps we could have provided twice the amount of vaccine doses. But based on the first phase results, the number of antibodies obtained with 100 micrograms was much better than 25, and we had no data about 50. For me, it was important to make a decision based only on the data we had.
"In hindsight, if you look back at Moderna's first and second vaccine trials, both of which had 100 microgram doses, the results speak for themselves. Our dose has 100 micrograms for the first and second doses. Pfizer's has 30 micrograms, and in the third shot – 50."
Q: Is Moderna's vaccine more effective?
"When it comes to vaccinating a healthy population, 30 micrograms seems to be enough, but as time goes on and you get to populations that are harder to inoculate - cancer patients, those with autoimmune diseases - you see that our vaccine is a little more effective."
Q: Does this mean that those vaccinated with Moderna might not need a booster? For they received 200 micrograms altogether.
"What's more important is how frequently the immune system was exposed to the virus, not how large of a dose he or she received."
Q: Why do you think Pfizer's vaccine is more common, at least in Israel?
"Pfizer's success in Israel – and I have tremendous respect for CEO Albert Burla – is that they have worked with the country exceptionally well, compared to other countries. Pfizer gave priority to Israel because it was the first one to say it was purchasing, and also because it provides data that is passed on to the rest of the world, to know what the right thing to do is, which proved successful.
"Israel deserves credit, and first and foremost the team of Dr. Osnat Luxenburg [director of the Health Ministry's Medical Technology and Infrastructure Administration]. I called them in April last year and said, 'Israel should test our technology and sign up for pre-purchase.
"Her team did a fantastic job and concluded that Israel should not hold back, but go all out for the technology that looks most promising. It's after this that the country began to work with Moderna and Pfizer.
"You can see the difference between what happened in Israel and what occurred, for instance, in the European Union, which chose the [British-Swedish vaccine manufacturer] AstraZeneca, whose vaccines work with different technology. By the time they woke up and decided to buy mRNA vaccines, Pfizer and Moderna had already sold their doses.
"As an Israeli, I am proud that data from Israel confirmed the effectiveness of the first and second vaccine doses, and now confirm the effectiveness of the third shot. Israel is leading the way in how to use vaccines correctly."
Q: Were you not disappointed that Israel signed a contract with Moderna first, but ended up choosing Pfizer?
"The truth is, no. What's truly important is that people should get their vaccines and be protected. My mom told me at the time, 'I can't wait for the Moderna vaccine, and they are giving Pfizer doses now.' I told her, "Take what is available, the most important thing is that you should get inoculated.'
"The world needs more vaccines that both companies are capable of producing today, and at the end of the day, Moderna has sold all of its vaccines to date.
"The data that tells us about the effectiveness of our vaccine comes from the hundreds of millions of people in the United States and Europe who received it. That's why we were not harmed when Pfizer was the first [to develop]."
Q: A Pfizer executive once called Israel a sort of a laboratory that has guaranteed them exclusivity.
"Pfizer received exclusivity for one simple reason: it could supply the goods, while Moderna's vaccines arrived in Europe and Israel a little later. The first quantities that came off the US production lines were destined for the American market. Geopolitically, Pfizer had an advantage here, and they used it. I'm glad it worked out in Israel's favor."
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Q: What about the "laboratory" part?
"I don't think that Israel is a laboratory in the usual sense. As I understand it, he meant that there was an agreement to receive data in exchange for the supply of the vaccines. After all, when Israel received the vaccine it was no longer experimental, it could rely on the results of the third phase, and there was a global approval by then, including by the FDA.
"Israel is a laboratory because it has organized data, that comes from health funds, and vaccines have been administered to the population in an organized manner that could be monitored. Millions in the US received the same vaccines, at the same time, but because the American healthcare system is decentralized, it is impossible to receive information from the field as effectively as in Israel.
"The way vaccines were administered in Israel became a model for the whole world. A German journalist once asked me, 'The Israeli government is doing such a good job, what advice would you give to Germany's government?" I told him, "A country that has been in an existential danger since its inception knows how to deal with existential threats much better than any Western country that has never known such threats."
Q: Did the change of the Israeli government affect your work at Moderna?
"I didn't feel a difference, because my work always entailed communicating with Health Ministry experts, and those have not changed."
Q: And what about the change of US administration?
"This is probably not an answer that would fuel the media drama, but the truth is, no. The Trump administration was very supportive of vaccines, and so has the Biden administration. I spoke several times with David Kessler [President Joe Biden's COVID response chief] towards the end of the Trump presidency, to make sure he knew what we were doing. In this respect, the change of government has not had a significant impact on how we operate."
Q: What is your opinion on Britain's decision to fully open the country?
"I trust each local health ministry. Opening everything is not a scientific response, but one that finds the balance between public health, economic interests, and the good of the individual. In each country, it depends on the infection rate, the vaccination rate, and economic aspects."
Q: In Israel, there was a lot of debate about whether schools should reopen as usual.
"It's a difficult decision. I see it with my nephews – some study from home, some go to school. Of course, we would all like them to be able to go back to the classrooms, but it must be done carefully, because as long as the Delta variant is here, and as long as there are people who refuse to get vaccinated, the danger remains, especially with children. We don't know yet what the most optimal way to vaccinate children is, especially the youngest."
Q: Perhaps the time has come to learn to live alongside COVID and stop counting the deaths?
"That time will come, but it is not here yet, as long as the morbidity is high and the Delta strain is here, which for us was a surprise, by the way. We hoped the vaccines would be more effective, and we did find that they are effective against serious illnesses and death. But they are not effective enough to prevent infection, at least not two doses.
"Those who are [double-]vaccinated will have a runny nose [if they get infected with the coronavirus], but if you get three vaccines, you will be able to lead a normal life. Once the third vaccine is common among most of the population, we will see relief. The cases will not completely disappear, but it will be a new world in which we will learn to live alongside the virus and serious morbidity will be minimal."
Q: What about herd immunity?
"It's a good question. Once we take into account how contagious Delta is, [to achieve] herd immunity the level would need to be very high – theoretically speaking, more than 90% [of the population] would need to be vaccinated or recovered.
"It is a possibility, although I do not know how soon we will reach that. I believe by then, most of the pandemic will be behind us. There will be pockets of people here and there who are more prone [to getting infected] because they either did not get vaccinated or have weak immune systems, like cancer patients. These people we would need to continue supervising. But generally speaking, the population will learn to live alongside the virus."
Q: You said earlier that the Delta variant surprised you. Why so?
"Our biggest fear was a variant that would undermine the entire immune system, a variant that would change so much that the previous vaccine would not be effective. What we got was a variant that does not undermine the immune system critically, but has become much stronger. The ability of this virus [Delta] to replicate has increased exponentially.
"The Delta is a little bit different [than previous strains,] and antibodies are less effective in neutralizing it. That is what makes it so dangerous. If the virus were to leave the immune system, then it doesn't matter how many times you vaccinate, it would not be damaging. The third shot proves that Delta doesn't leave the immune system, but is a new step in its capability to replicate and infect. This we did not expect."