In the face of an ever-changing pandemic, medical scientists are racing to find out as much as they can about the deadly coronavirus – but it's an impossible task.
We're learning a lot about this deadly new disease, fast. But there's much more we must discover before we know when – and if – we can beat COVID-19.
In the midst of a pandemic, everything is urgent, especially with authorities warning the lifting of lockdowns restrictions may be dependent on a vaccine.
And it's a massive challenge to medical scientists the world over.
"It's almost surrealistic," US coronavirus Task Force adviser Anthony Fauci told the JAMA medical journal network. "I've kind of figured I just have to suck it up."
But it's an all-consuming task.
"I made some mistakes early on – I just didn't sleep much. Three hours is no good, you can't do that too many days in a row. I forget to eat sometimes, that's not so good."
The director of the National Institute of Allergy and Infectious Diseases learnt his trade combating HIV-AIDS.
He considers COVID-19 to be astounding.
"The pathogenesis (development) of this disease just fascinates me," Fauci said.
"I mean, I don't have a lot of time to look up at the ceiling at night because I don't sleep that much. But as a person whose research career has been focused on the pathogenic mechanisms of HIV disease, the idea that you can have somebody who is sitting down in his office, then feeling sick, getting febrile (a fever), goes home for five, six, seven days – and then all of a sudden, they crash. And they crash over a few hours. They go from feeling okay but febrile and achy to all of a sudden having difficulty breathing …
"I have to be humble and say, I don't know what's going on there. But boy, we need to find that out because unless you know what the pathogenic mechanism is, it's going to be tough to do intervention."
There are a handful of key questions we all need answered to crack the code of COVID-19.
HOW CONTAGIOUS IS IT?
COVID19 numbers are a moving target. That's not the fault of doctors, scientists – or nations.
It's the reality of the scramble to get reliable data amid a rapidly exploding pandemic crisis.
And this virus is a particularly slippery one, with an enormous range of symptoms sweeping from none to fatal. As many with mild to no discomfort will not bother to seek medical help, they are slipping under the radar. But that number has big implications for future levels of immunity.
"One of the biggest surprises to me in this is, it's a respiratory virus – and how it is spread," said Professor Preeti Malani of the University of Michigan.
"How much of a role does asymptomatic spread have? And if it's a huge role, I have to believe that our denominator (spread rate) is gigantic, and that we haven't picked it up yet."
Studies released in recent weeks indicate that 30 per cent of everyone infected with COVID-19 doesn't show symptoms, yet may continue to pass on the disease.
HOW DOES IT SPREAD?
"I think this is one that the infectious disease community is pretty interested in," Malani said. "I would say the easy answer is likely a spectrum."
COVID-19 is a respiratory infection. So its main manner of spread is likely to primarily be a droplet. These are spread person-to-person through coughing, sneezing and breathing.
But we've also realised it can also settle in the environment, where it can be picked up by unknowing fingers and transferred to the eyes and nose. And suspicions are falling on faeces after high rates of spread being detected in high-rise apartments with faulty plumbing.
"(Transmission has) become a much, much bigger issue and we're still learning that," Malani says.
But the odds of COVID-19 being picked up from packages is very low.
"If you took something that was heavily contaminated, and then you rubbed your eye or your nose or your mouth, in theory, you could infect yourself," she says, "but, you know, hopefully none of us are doing that!"
Malani said that given the asymptomatic spread and the potential lifetime of the virus in the open, the recommendation is for the public to assume that everyone they meet may has it. Especially themselves.
Which is why advice has changed for people to wear homemade masks when they go out in public. Not so they don't breathe it in themselves. But so that they don't breathe it out.
"There's not really a downside to it, particularly if you're not taking supplies away from the healthcare setting."
CAN YOU GET IT MORE THAN ONCE?
"So part of the answer is, we're not totally sure," Malani said. "But we have some data to suggest that it is unlikely. I know there were some reports … (but) I don't think I saw any peer-reviewed publications. "
Essentially, she said, the risk of tests producing false-positive results is higher than the likelihood of reinfection. But the need for a careful examination of the possibility remains.
"The feeling is from (the coronavirus) SARS1 that the peak was around four months and that immunity lasted two or three years in people. So that's a pretty good timeline in terms of thinking about vaccines and other therapeutics."
Fauci says the issue of immunity is yet to be looked at as carefully as he'd like, and it's very difficult to get real-time evidence as this pandemic unfolds. But he remains hopeful based on what we know and what we've seen.
"So we're making an assumption, which I think is a reasonable assumption, that this virus is not changing very much. And if we get infected in February and March and recover in September or October, that the person who's infected I believe is going to be protected. We don't know 100 per cent for sure. But I think that's a reasonable assumption."
HOW DEADLY IS IT?
We just don't know, said Malani.
"We are … picking up only like the tip of the iceberg in terms of the serious cases.
"Unless you are really sick, you're coming into our emergency department or being hospitalised, you're probably not going to get a test unless you might be a healthcare worker or you fall into some other high-risk category."
What we know is those who get it bad, get it bad.
• Premium - Covid 19 coronavirus lockdown: Jacinda Ardern to reveal level 3 rules this week
• Covid 19 coronavirus: What you need to know about Monday's big developments
• Covid 19 coronavirus: New Zealanders should 'take heart' in declining case numbers but grave fears remain for a group of dementia patients
• Covid 19 coronavirus lockdown: 5 deaths, 19 new cases, 75 recoveries - Ashley Bloomfield, Jacinda Ardern with latest updates
Some figures suggest up to 51 per cent of those who enter intensive care units (ICUs) with the disease don't come out alive.
"It'll be a long time before we really know the true fate case fatality rate, but regardless, it is higher than a lot of seasonal flu, respiratory virus, and it's certainly higher than anything we would want to see."
ARE THERE ANY TREATMENTS?
Fauci said it's still too soon to know what works and what doesn't. "You know, we all like to see a positive result. But one of the advantages of doing a (systematic) randomised trial is that if you find something that doesn't work, just get it off the table quickly and move on to the next one. But it will be soon, as you'll know as you will see the papers coming in."
When it comes to plasma serology (transplanting immunity from someone who has had the disease), Fauci said the method has merit.
"That's at least a good approach that's worth doing and trials are underway," he said. "Hopefully, we'll get some data soon on that it might be a good way of therapy."
Malani is also optimistic.
"I'm hopeful that it will work because I'm not sure we're going to have an antiviral or other treatment that's going to work and that's available on a large scale."
While the serum tests in China are far from conclusive, Fauci said it was "really interesting" that the critically ill subjects recovered faster than usual.
"So this begs for a randomised trial," she said. "But in the meantime I think we have to be a little bit flexible … and the whole ethics around randomisation are getting blurred in some places."
WILL THINGS GET BACK TO NORMAL?
Fauci said this is a pressing question. "I spent until the wee hours in the Roosevelt Room in the West Wing of the White House with my colleagues on the task force, trying to integrate the public health issues into the practicality of (lifting the lockdown) after 30 days. What are the kind of things you have to have in place to safely and carefully, march towards some sort of normality?"
He said he needed "to get a feel for" how far the virus has spread, and how many people have recovered and are no longer vulnerable.
"Because those are the people that when you put them back to particularly critical infrastructure jobs, that you worry less about them driving an outbreak than those who fact are anybody negative and very likely have never been exposed."
Malani said the pandemic "can't go on forever," but is wary of early positivity.
"I don't know that we can get back to all activities, you know, and particularly the kind of things that happen on a college campus or in the … summer. That's going to be a difficult thing, unless we find out the denominator (infection rate) is really high".
Both agree there is danger in moving too early, which would undo all the good of the weeks spent in lockdown so far.
"We better make sure that we very aggressively and vigorously do not allow the resurgence of a case or two or three or 10 or 20 get out of hand" Fauci said. "We've got to jump all over that so we don't have, you know, recurrent peaks."
Keeping it under control is the imperative we face, he said.
"We've got to be careful we don't ever let it get out of hand again.
We have to change our mindsets, he said: "Simple things that we didn't take seriously before – constant handwashing, when people have fevers, keep them out of places where they can spread. Do not send a sick child to school. Do not send a sick worker into the workplace. Don't anybody ever shake hands again. I mean, it sounds crazy, but that's the way it's really got to be until we get to a point where we know that the population is protected."