Editorial: The hunt for a Covid 19 coronavirus vaccine

EDITORIAL

New Zealand's ride through the Covid-19 coronavirus pandemic was summed up by Prime Minister Jacinda Ardern this week in a baker's dozen of words: "We will have to keep stamping Covid out until there is a vaccine."

In pursuing the strategy of "elimination" - whichever definition of the word is pour du jour - we have rejected the concept of herd immunity, taken the kindest track and thrown our lot in with the search for a vaccine.

Many of the world's biggest biotech companies are hard at work, and reports say more than 100 vaccines are in pre-clinical testing, and a handful in human testing.

This isn't a case of identifying a winner and pushing a silver bullet into mass production however. Sars-CoV-2, the virus that causes Covid-19, is a slippery customer. Being simple, tiny single-strand RNA viruses, coronaviruses tend to mutate quickly, which means vaccines have previously been effective only for specific subtypes.

Coronaviruses are not very robust, explains emergency doctor Gary Payinda. They tend to struggle in cell culture. Rather than growing quickly in massive "farms" of purpose-bred cells, they require painstaking, slow, and expensive growth in live chicken eggs.

Additionally, all vaccines need expensive safety and efficacy testing in humans, because of the risk of provoking an immune response so intense that it harms the patient.

• Covid19.govt.nz: The Government's official Covid-19 advisory website

But researchers are pressing on. A University of Oxford team has begun injecting volunteers with a new vaccine created by inserting genes for a spiky protein that studs the outer surface of the new coronavirus with another, harmless virus. The immune system detects the foreign protein and makes antibodies to fight it, priming them to react quickly if the person eventually is exposed to Covid-19.

Already ahead of Oxford is China's CanSino Biologics, which has begun the second phase of testing its vaccine candidate, in a similar approach.

Two US companies are also testing vaccines made from copies of a piece of the virus' genetic code and two other Chinese candidates are being pursued that use older technology.

A team at the University of Queensland is using the genetic sequence of the coronavirus to produce an identical protein to the one on the surface of the virus. This protein engages the body's immune defences and injecting it should provide an optimal immune response and protection.

University of Otago's Webster Centre for Infectious Diseases has joined the efforts of several overseas teams. Otago could hold the key in the university's high-security PAC3 laboratory. At least 20 research groups, in New Zealand and abroad, are now closely involved in Otago collaborative research to test anti-viral drugs and to help develop a vaccine.

Of concern, once a breakthrough is made, is the capacity to scale up production. The first nation to crack the code will be understandably keen to vaccine its own people. That's where New Zealand's innovative and highly collaborative style of research could work in our favour.

Science will be our ticket off this horror carnival ride because, quite simply, it has to be. It is our only way out.