A vaccine for coronavirus is the goal, but what does it take to get there? – ABC News

New South Wales Premier Gladys Berejiklian has warned that social distancing restrictions will be in place in her state "until a vaccine is found".

But what exactly goes into developing a vaccine for a new disease? And how long will that take?

SARS-CoV-2, the virus that causes coronavirus, was only identified a few months ago, and while researchers have been rapidly finding out about the virus and the disease it causes, there's still so much about it we don't understand.

But that doesn't mean the quest for a vaccine is coming from a standing start.

Rapid vaccine development technologies mean that the time it takes to develop a vaccine, which used to be in the order of two to five years, could be condensed down to the 12 18 month timeframe that many experts have been referring to.

And the science that has gone into developing past vaccines also gives researchers a jump on COVID-19.

Even so, creating a new vaccine isn't as simple as taking an existing vaccine and swapping the viruses, said Larisa Labzin, an immunologist from the University of Queensland.

"For each virus or different bacterium that causes a disease, we need a different vaccine because the immune response that's mounted is different," Dr Labzin said.

"Just because we've got a really good vaccine against polio doesn't mean the same thing will work with coronavirus because it's so different."

University of Queensland researchers are one of the groups worldwide working on a potential vaccine for COVID-19.

(Supplied: The University of Queensland)

University of Queensland researchers are one of the groups worldwide working on a potential vaccine for COVID-19.

Supplied: The University of Queensland

Before we had vaccines, the main way to become immune to an illness was to catch it and then recover.

In the process of recovering from an infection, your body develops antibodies and specialised immune cells that learn to fight that particular illness-causing invader, or pathogen.

If you are exposed to the same pathogen in the future, your immune system "remembers" it and dispatches those purpose-built antibodies and specialised immune cells to fight it so you don't get sick again.

"The point of a vaccine is to trick your immune system into thinking it's seen it before without having to go through the whole process of actually getting sick with the virus," Dr Labzin said.

There are a few techniques researchers are exploring for COVID-19 that can be used to stimulate this response in the body, and they each have their pros and cons.

These involve introducing a "live" virus into the body, but one that has been "attenuated" or weakened.

Live attenuated vaccines, such as those used for measles, mumps and rubella, cause a strong immune response, but they take a long time to make and "there's always the possibility that they could mutate within the body or the population to become more dangerous again" Dr Labzin said.

Inactivated vaccines, such as those used for Hepatitis A and the seasonal influenza injection, contain the whole virus, but it's been "killed" by being exposed to ultraviolet light or a chemical.

"The virus is there but it's in a straitjacket. It's still got all its components for the immune system to recognise and mount a response against but it can't cause disease," Dr Labzin said.

The downside of these is that because the virus isn't a threat to the body, the body might not mount much of an immune response to it, and the dose of virus in the vaccine might need to be higher to cause enough of an effect.

Subunit and similar types of vaccines introduce a fragment of the virus into the body, for example, the "spike" protein that sticks out on the shell of a coronavirus.

The spike protein is what actually binds to the receptors in your body and allows the virus to enter your cells.

The idea behind a subunit vaccine is that when the body recognises the protein it creates specialised immune cells that block the receptors, effectively shutting down the door to the virus.

Dr Labzin said there are quite a few subunit vaccines in development for COVID-19 because they have the benefit of being relatively quick to make in comparison to live attenuated and inactivated virus vaccines.

But they carry the same downside of inactivated virus vaccines, in that the challenge is getting the body to recognise the virus fragment as enough of a threat to create an effective immune response.

Unlike the other types, which include the actual virus or portions of it, genetic vaccines simply contain DNA or RNA the code that tells cells what to produce.

These vaccines take advantage of the body's own cells, giving it instructions to create the protein of the virus the vaccine is aiming to protect against.

The body then detects both the genetic material and new protein as foreign and mount an immune response against it.

These types of vaccines are relatively easy and inexpensive to make, but they're newer technology.

Dr Labzin said RNA vaccines were so new there aren't actually any existing vaccines of this type yet.

These vaccines introduce a different type of virus that has been engineered to include proteins of the virus the vaccine is aiming to protect against.

Even though this type of vaccine involves a virus, it can't cause disease but does stimulate an immune response.

"There are licensed vaccines of that type, it has a known track record of working," said Trevor Drew, head of CSIRO's Australian Centre for Disease Preparedness.

A colorised scanning electron micrograph image of a VERO E6 cell (blue) heavily infected with SARS-COV-2 virus particles (orange), isolated from a patient sample.

(Flickr: NIAID)

A colorised scanning electron micrograph image of a VERO E6 cell (blue) heavily infected with SARS-COV-2 virus particles (orange), isolated from a patient sample.

With so many potential avenues to explore, how do researchers and funding bodies know where to direct their efforts?

In an attempt to get an effective COVID-19 vaccine ready as quickly as possible, Dr Lazbin said the World Health Organisation (WHO) and Coalition for Epidemic Preparedness Innovations (CEPI) are "trying to put their eggs in lots of different baskets".

The WHO has released a list of more than 60 vaccines in development all around the world, including a number in Australia.

But even once a vaccine is developed that has promise, there are hurdles it must clear before it can be rolled out around the world.

You might have heard about different phases of clinical trials before. Here's what they mean for the purposes of a COVID-19 vaccine:

Amidst these, the potential vaccine also has to be approved for use by relevant regulatory bodies and, crucially, it has to be manufactured in sufficient amounts and distributed around the world.

As mentioned, there are multiple research groups investigating different approaches to developing a vaccine for COVID-19. Most of these are still at the preclinical phase, although a few in the WHO document are in Phase I trials.

Last week, the CSIRO announced it had begun testing potential vaccines on ferrets at its Australian Animal Health Laboratory in Geelong.

This pre-clinical stage, which is expected to take three months, involves testing potential vaccines for effectiveness as well as evaluating how best to deliver the vaccine, such as via an injection into the muscles or a nasal spray.

The CSIRO site is a pipeline for a number of potential COVID-19 vaccines.

Professor Drew, who is leading CSIRO's COVID-19 virus and vaccine work, said the facility had actually been preparing for these tests since before COVID-19 even broke out.

"We called it Disease X. we didn't know what would come but we knew something would come," he said.

"And then suddenly COVID emerged as the disease."

Ezekiel Uba Nwose, a medical scientist at Charles Sturt University, said you could only speed up processes by so much.

"Normally vaccines take up to five years or more to develop, but ... the relevant authorities can decide to speed up on the conventional protocols to fast-track bringing it to trials," Dr Nwose said.

"No matter what, it needs to undergo trials and validation.

"With the COVID-19 vaccine, I think the earliest several authorities have indicated the earliest we are going to get it is 2021."

Yes, it's possible, Dr Labzin said. Every virus is different and what has worked in the past may not work for the new coronavirus.

"We don't have vaccines against any coronavirus yet," she said.

SARS, MERS and some forms of the common cold are caused by other coronaviruses.

But she's optimistic.

"I think that by taking so many different approaches we should be able to."

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A vaccine for coronavirus is the goal, but what does it take to get there? - ABC News