A Technological History Hiding an Institutional Argument
Saloni Dattani's essay for Works in Progress traces 230 years of vaccine development with the thoroughness of a textbook and the narrative momentum of something far more readable. The piece moves from Edward Jenner's lucky break with cowpox in 1796 through Pasteur's systematic methods, the microscope revolution, the rise of subunit vaccines, and the genomic era that gave us mRNA platforms. It is, on its surface, a history of science. But underneath the chronology runs a pointed argument about investment and progress that deserves scrutiny.
From Serendipity to Engineering
The strongest thread in the essay is the contrast between early vaccine development as accident and modern vaccine development as design. Dattani captures the precariousness of early efforts vividly. Jenner's vaccine stocks "would die out repeatedly, and needed to be rederived from scratch many times." Keeping a vaccine alive in the nineteenth century meant maintaining "arm to arm chains of transmission just to preserve the material." These details make the sheer fragility of early public health infrastructure tangible in a way that broader histories often gloss over.
The Pasteur sections are equally compelling, particularly the account of how his assistant Emile Roux stumbled onto attenuation during Pasteur's summer absence. Roux "tried reculturing flasks that had stood for weeks, but the broth had soured, and the bacteria grew poorly." When he injected the weakened cultures into chickens and some survived, then survived again when exposed to lethal strains, it was the kind of productive accident that only happens inside a sustained research program. The essay rightly frames this not as mere luck but as the result of systematic experimentation that could capitalize on the unexpected.
The Microscope as Protagonist
Dattani gives unusually generous attention to instrumentation, and the essay is better for it. The progression from light microscopy's hard limits through electron microscopy to cryo-electron microscopy reads as its own mini-narrative of scientific progress. Ernst Abbe's discovery that optical resolution was fundamentally capped at "about half the wavelength of visible light, roughly two hundred nanometers" is presented not as a footnote but as a genuine crisis that shaped the trajectory of virology for decades.
The payoff comes with the RSV vaccine story. For decades, respiratory syncytial virus resisted vaccine development. The breakthrough required seeing the virus's fusion protein at atomic resolution, then engineering it to stay locked in its pre-fusion shape. Without cryo-electron microscopy, this would not have been possible. As Dattani frames it, the ability to visualize pathogens at the atomic level is not merely a convenience but the foundation on which modern vaccine design rests.
Fewer Antigens, More Vaccines
One of the essay's most counterintuitive points concerns the trajectory of childhood vaccination. The pertussis story illustrates this well. Japan's suspension of its whole-cell pertussis vaccine in the 1970s, followed by rising disease and death, spurred the development of acellular vaccines containing only the antigens necessary for protection. The result is that children today "receive more vaccines... but fewer and more targeted antigens than they did back in 1900, when only the smallpox vaccine was widely available."
This is a useful corrective to public anxieties about the childhood vaccine schedule. But Dattani is honest about the tradeoffs: the acellular pertussis vaccine "was safer but also less effective, with immune protection waning after a few years." The essay does not dwell on this tension, perhaps because it complicates the narrative of steady progress. The waning immunity problem with acellular pertussis remains a genuine public health challenge, and the resurgence of whooping cough in vaccinated populations has been well documented. A fuller treatment might have grappled with whether the push for precision has, in some cases, traded durability for safety.
The mRNA Leap and What It Obscures
The essay's treatment of mRNA vaccines is characteristically clear. The key obstacles were real: mRNA "triggers strong immune reactions, is chemically fragile before it enters cells, easily destroyed by enzymes." The breakthroughs by Katalin Kariko, Drew Weissman, and others are presented as the culmination of decades of foundational work. The promise is enormous:
The result was a rapid, adaptable platform that could be redesigned almost as quickly as new threats emerged: because it bypasses microbial factories entirely, each new vaccine can be formulated and updated within weeks.
What the essay does not address is the gap between technological capability and actual deployment. The COVID-19 pandemic demonstrated both the speed of mRNA vaccine development and the enormous institutional, logistical, and political barriers to getting vaccines into arms worldwide. Technology that can be "formulated and updated within weeks" still took months to reach clinical trials and over a year to achieve broad distribution. The bottleneck was never primarily scientific. It was regulatory, manufacturing, and distributional. Dattani's framing implies that continued investment in vaccine science is the primary constraint on progress, but the pandemic's lessons suggest that investment in manufacturing capacity, supply chain infrastructure, and global health equity may matter just as much.
The Golden Age Claim
Dattani's thesis is stated plainly at the opening and closing: "We are living through a golden age of vaccine development." The evidence is substantial. In the last five years alone, effective vaccines have been developed against four additional diseases. The toolbox available to vaccinologists today, from cryo-electron microscopy to reverse vaccinology to mRNA platforms, is incomparably richer than anything Pasteur or even mid-twentieth-century researchers could have imagined.
But there is a counterpoint worth raising. Previous golden ages in biology, as Dattani herself notes, eventually faded. The golden age of antibiotic development in the mid-twentieth century gave way to decades of stagnation as economic incentives dried up and resistance grew. Whether the current vaccine renaissance continues depends not just on scientific capability but on sustained funding, functional regulatory systems, and public trust, the last of which has been significantly eroded in many countries. The essay's optimism is not unfounded, but its conditional phrasing is doing real work:
If we invest in them, the future holds many more. The golden age of vaccine development lies ahead of us.
That "if" carries the weight of the entire argument. The technological capacity exists. The question is whether the institutional will matches it.
Bottom Line
Dattani's essay is an exceptionally well-constructed history of vaccine technology that doubles as an argument for continued investment. The science writing is precise without being inaccessible, and the attention to instrumentation and technique gives it a depth that most popular treatments of this subject lack. Where it is less convincing is in its relative silence on the non-scientific barriers, regulatory, political, economic, that have historically determined whether golden ages of biomedical innovation translate into golden ages of public health. The technology has never been better. Whether that is enough depends on factors this essay acknowledges but does not fully confront.