Moncef Slaoui’s “Ambitious Mission” Brought Success and Frustration
The former chief scientific officer of Operation Warp Speed reflects on a year of achievement, shortcomings, and hopes for the months ahead
Published February 02, 2021


Monsef Slaoui, MD
Chief Science Advisor to Operation Warp Speed
Moncef Slaoui, the former chief scientific officer for “Operation Warp Speed,” says the program delivered on its primary mission “100 percent,” even as he acknowledged secondary failures. These include an overreliance on states to execute vaccine delivery and inadequate communication to manage expectations about the speed of vaccine rollout.
As Slaoui, a veteran vaccinologist and longtime advocate for pandemic preparedness, concludes a brief tenure advising the new administration, he offered a rare insider perspective on the “ambitious mission” of Operation Warp Speed (OWS), along with a cautiously optimistic view of the coming months.
Slaoui shared his reflections with audiences during the keynote address of a New York Academy of Sciences symposium, The Quest for a Covid-19 Vaccine. His comments come amid heightened concerns about the efficacy of Covid-19 vaccines against newly emerging, highly transmissible variants, and ongoing difficulties with vaccine supply and deployment in the United States and around the globe.
Under Slaoui’s leadership, Operation Warp Speed—a partnership that did not exist one year ago—oversaw the development, testing, and deployment of a portfolio of diverse, highly effective, and safe vaccines against a wildly transmissible respiratory pathogen. Slaoui hailed the “visionary approach” of OWS in uniting public and private entities that don’t always collaborate effectively, while synchronizing development and clinical trial processes to maximize speed without compromising safety. “We decided to go for the clinical development of this vaccine and the process development and manufacturing absolutely in parallel—in contrast with what happens in the normal setting,” he said. Such risks proved well worth the gamble when the first Phase 3 trial data, from mRNA vaccines developed by Moderna with support from OWS and privately by Pfizer/BioNTech, were, at 95 percent effectiveness, “beyond everyone’s wildest dreams,” according to Slaoui. “Great science leads to great outcomes...you couldn’t invent this, frankly.”
While the rapid-fire development of multiple vaccines amid a pandemic is already being hailed as a great achievement in science, Slaoui acknowledges two key failures, both rooted in a mismatch between expectation and the realities of vaccine deployment in the United States.
Slaoui asserts that both his own communication through OWS, as well as guidance from the CDC and other agencies, didn’t go far enough in helping the public anticipate and cope with the initial pace of vaccine production and distribution. “We failed to explain that we would need to go in a prioritized, step-by-step way...that it wasn’t going to happen overnight,” he said. This communication gap was compounded by what Slaoui characterized as the “wrong assumption” that individual states and counties had adequate resources and infrastructure to efficiently deliver vaccine doses as they became available. “It’s been a very difficult experience, and some really important learning,” he said.
The impact of misinformation on vaccines, hesitancy about their use, and public mistrust, is impossible to ignore, and Slaoui sees the politicization of the pandemic as “an extremely disappointing dimension” of the whole process. “Science has nothing to do with politics,” he said, issuing a half-joking plea that the next pandemic “please not happen during an election year.”
The emergence of several new, more transmissible variants of SARS-CoV-2 has prompted international alarm over the potential impacts on vaccine efficacy. Slaoui is both “very concerned” about the situation and also “very reassured” by trial data from vaccine candidates developed by Johnson & Johnson and Novavax, and tested in the UK and South Africa where two of the most concerning variants have emerged. Both vaccines confer 50 percent or more protection against these new types, and provide high levels of protection against severe disease, a point Slaoui emphasizes as critical as the variants spread. “My expectation is that protection against severe disease, hospitalization and death is likely to be much broader across variants than protection against infection and prevention of transmission,” he said.
As manufacturing capability expands and more vaccines enter the market, Slaoui estimates that every American who wants a vaccine will be able to receive one by summer—a momentous achievement for which he credits the unprecedented collaborative work of researchers around the world, along with thousands of industry partners and hundreds of thousands of clinical trial volunteers. Looking back, “this has been the best time of my life as a vaccinologist,” he said.