Vaxxers: the inside Story of the Oxford AstraZeneca Vaccine and the race against the Virus

The 'inside story' of how Oxford scientists developed the AstraZeneca vaccine within a year of the SARS-CoV-2 outbreak...

The coronavirus epidemic has profoundly influenced humanity's response to many things that seemed unimaginable. Think lockdowns, repeated tests for a virus, wearing masks, and a new vaccine within a year of the blight.

In the pre-pandemic era, the default wisdom on vaccines was that they took a minimum of 10-15 years from concept to being available as a commercial product.
Potential vaccine candidates have to be tested if they can destroy bacterial or virus cells in test tubes, then in small animals, large animals and finally, people.

This is a three-stage process with phase-1 trials testing if healthy people inoculated with a vaccine produce the necessary antibodies, then it's tested on small groups to see if those who get the vaccine are better protected than those who did not and finally, a similar process is repeated in thousands in hospitals across the country, or even internationally, to see if the protection holds. At every stage potential side-effects and adverse events are keenly watched - after all, the purported benefits cannot outweigh possible harm.

A head start
There are reasons for the long gestation and seen in this light, to have several viable vaccines within a year of COVID-19 is a miracle of sorts. Vaxxers, by Sarah Gilbert and Catherine Green, is the "inside story" of how one of these vaccines, Oxford AstraZeneca, marketed as Covishield in India, was developed. Both scientists are part of the team at Oxford University that developed the vaccine. The book is a readable guide to the steps to developing vaccines. The authors, who alternate on chapters, highlight the challenges of adapting to a life of incessant scrutiny, the barrage of public interviews along with managing the daily grind of scientist life: writing grants, conducting experiments, managing laboratories.

However, the most important insights lie in how the Oxford vaccine got a headstart. Gilbert and her group were already working on designing vaccines against emerging pathogens.

Pivotal moment
The 2014 outbreak of the deadly Ebola virus in Guinea, West Africa, that killed nearly 11,000 people, is a pivotal moment in the quick development of a COVID-19 vaccine. Gilbert, a professor of vaccinology, was involved in the testing of an Ebola vaccine. "These experiences formed the foundations of what we've done� because of what happened with Ebola, learning what worked well and what did not, we were able to design, make and test a vaccine with unprecedented speed and with high levels of confidence in the outcome," she writes.
From the Ebola vaccine they got the idea to develop a vaccine that was a "replication-deficient recombinant simian adenoviral-vectored vaccine".

Novel approach
An adenovirus is a virus that easily infects human cells. Removing a single gene creates a form of the virus that still infects people but can't replicate within the body. Unlike bacteria, viruses can only make more of themselves by taking over the replication machinery of cells. This excised gene is replaced with another which, once inside the body's cells, instructs cells to make a particular protein against which the body's immune system triggers a response.

The resultant antibodies and the priming of the immune system against the proteins that characterise a particular virus then protect the person from a future live infection. The novelty of this approach is that the gene that is added can be either an Ebola virus gene, or a coronavirus gene or whatever infection is doing the rounds. While there are several alternate technologies to make vaccines, each has relative advantages and demerits.

The book does not answer why in spite of such rapid development much of Africa has not been vaccinated even as other countries are already rolling out booster (third) doses as a new variant Omicron causes havoc. While much more will be written of this period in human history, Vaxxers will certainly be an integral part of this bibliography.

Courtesy: THE HINDU