Why Vaccines Are So Difficult to Develop
An inside look at why we are so far from a Covid-19 vaccine
The first major outbreak of a coronavirus was nearly two decades ago. As that strain raged through Asia, there was an immediate effort to develop treatments and vaccines against the novel pathogen. Impressive measures were put into place to curb the spread of the disease and prevent people from contracting it. Vaccines stood as the crown jewel of this effort: to develop a safe and effective one would have been a monumental accomplishment.
Roughly a decade later, after the dust had settled on the original SARS outbreak in Asia, a new strain of the coronavirus emerged in the Middle East causing a similar spectrum of disease symptoms. This new strain, now known as MERS-Cov, ran a similar course. Again, a renewed enthusiasm for developing vaccines surfaced.
Now, nearly two decades from the original SARS outbreak, we face yet another novel coronavirus outbreak, this time emerging from China. This one has, of course, spread rapidly throughout the globe. This pandemic is reminiscent of the prior two coronavirus outbreaks but dwarfs them in its transmissibility and lethality. Once again, the medical community jumped into action to develop drug treatments and vaccines against the newest strain of coronavirus, now known as SARS-Cov-2 or Covid-19.
The question is: Why didn’t we already have a vaccine against coronavirus? The answer to this is complex and goes far beyond the difficult task of identifying and testing a viable vaccine.
In 2014, Dr. Peter Hotez of the School of Tropical Medicine at the Baylor College of Medicine and others wrote an article outlining the urgent need for a vaccine targeting the strains of coronavirus that cause SARS and MERS. At the time, Hotez argued that we not only faced obvious demand — as highlighted by two large coronavirus pandemics — but we also had the information necessary to begin developing vaccines. Researchers had already sequenced the coronavirus genome and gained a clear molecular understanding of how coronaviruses invade the human respiratory systems.
There are currently over four dozen different vaccines awaiting clinical trials. Nearly all of…