As the number of confirmed coronavirus cases passes 2 million worldwide, we look back at the first 100 days of COVID-19 and how they changed the world.

The global coronavirus pandemic will change air travel as we know it, with more emphasis on passenger health and in turn, higher airfares, experts say.

For years airlines and travellers have been enjoying a golden age of travel. Low oil prices and fierce competition meant affordable airfares for passengers while a strong global economy, increased collaboration and new fuel efficient aircraft allowed airlines to create new and exciting products and routes.

But the deadly Covid-19 virus which has spread throughout the world brought that golden age to a grinding halt as passenger demand fell off a cliff and countries around the world closed their borders in an attempt to contain the spread of the disease.

The International Air Transport Association (Iata), which represents nearly 300 airlines, said some 25 million jobs were at risk of disappearing as airlines grounded their fleets and began cost cutting measures in an attempt to survive the Covid-19 crisis.

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As of early April, the number of flights globally was down 80 per cent compared to the same time in 2019 and passenger revenue was expected to fall 55 per cent in 2020

Iata chief executive Alexandre de Juniac said the industry had never been shuttered on this scale before.

"Consequently, we have no experience in starting it up. It will be complicated," de Juniac said.

DAVID WHITE/STUFF Air travel as we know it will change, say industry experts.

"We will have to adapt operations and processes to avoid reinfections via imported cases."

A multi-stakeholder approach would be essential, he said.

"We are not expecting to re-start the same industry that we closed a few weeks ago."

He said the industry did not want to repeat mistakes made after the September 11 terror attacks when many new processes were imposed in an uncoordinated way.

"We ended up with a mess of measures that we are still sorting out today."

After September 11 global travel demand slumped and a range of new measures were introduced to the aviation sector to improve security and reduce the chance of future plane hijackings.

Greater airport screening and security was introduced, identification checks became more strict, cockpit doors were locked and made bulletproof and passengers were banned from bringing liquids of certain amounts on planes.

JOHN ANTHONY/STUFF Aviation consultant Christoph Mueller says airfares would need to increase if social distancing is required on planes.

Aviation consultant Christoph Mueller, who has been chief executive of Malaysia Airlines and Aer Lingus, spoke with Capa - Centre for Aviation about what the future of aviation might look like.

Just like with 9/11, greater measures around passenger screening at airports would be born out of the Covid-19 pandemic.

He said an international regulator would need to step in so each country wasn't coming up with different types of screening and legislation.

"Someone who is backed really with the intelligence expertise has to draw up very very quickly the rules of the game," Mueller said.

"We have to get to grips very very soon to have consistent measures all over the world which are guarded really by medical professionals to tell us and the travelling public what is safe and unsafe."

AP Strict screening measures were introduced to the aviation sector after 9/11. Covid-19 will have a similar impact, experts say.

It would probably have to start with "a very high yardstick" which could be lowered as the situation improved, he said.

"It needs to be an understandable and universal rule for each and everybody otherwise we will fail."

Increased screening measures would come at a huge cost to the aviation industry, he said.

If social distancing was required on planes that would also cost airlines because they would not be able to carry as many passengers. As a result airfares would need to go up, he said.

DAVID WHITE/STUFF Passengers may need to queue at airports to be medically checked before flying in the future.

One of his main concerns, he said, was that the airline industry would be set back 10 to 15 years with regard to innovation, predominantly on the customer facing side.

The industry had reached a stage where money was available to digitalise the industry across the board ranging from customer experience to airline operations, he said.

"Literally each and every process in an airline could have been made more efficient.

"My biggest fear is that right now these funds will not be available for the forseeable future and the industry falls behind."

Corporate travel, traditionally a big revenue stream for airlines, would be heavily impacted in the future as a result of Covid-19, he said.

SUPPLIED A need for social distancing in cabins would affect airline's margins and result in more expensive airfares.

Historically when the aviation sector was hit with a crisis, such as 9/11 and the Sars epidemic, corporations had introduced new travel regulations which meant fewer people were allowed to travel, he said.

There would also be a psychological impact on passengers who may be deterred from air travel due to the perceived risks, he said.

Those fears would dissipate faster in Asia where there was lower penetration of Covid-19 than in the United States and Europe, he said.

The recovery of air travel in Asian was more likely to be a "v shape", he said.

​Capa chairman Peter Harbison said health had come to the forefront of the aviation sector and it would change the way the industry operated.

"This sort of event will recur," Harbison said.

"We're looking at the same sort of impact that 9/11 had on security."

Passengers would need to be medically checked before passing through an airport and boarding an aircraft, he said.

There may perhaps be half as many people on an aircraft in future due to social distancing rules, which would need to be standardised across the industry, he said.

While domestic travel may recover in the near term, border controls were going to substantially restrict any short-term international travel, he said.

"International is going to stay very very difficult for probably quite a long time."

DAVID HALLET/STUFF Airports are arguably higher risk environments than aircraft for transmission, Capa chairman Peter Harbison says.

Economist Benje Patterson said a vaccination would need to be available before 100 per cent free movement of people internationally could occur.

Passengers would need a certificate of vaccination to board international aircraft, he said.

Once Alert Level 4 restrictions in New Zealand were lifted it would be a while before border restrictions for international air travel were completely relaxed, he said.

However, there was a potential middle ground in the short term that could allow for an earlier reopening of borders, he said.

SUPPLIED Economist Benje Patterson says rapid testing kits could allow for a middle ground in opening our borders.

That would involve rapid testing of all international passengers for coronavirus, both prior to boarding and on arrival in the country, he said.

"Anyone with a positive result would denied boarding, self-isolated or quarantined," Patterson said.

To get to such a middle ground would require widespread availability of rapid test kits, that could be performed with high accuracy, low cost and without encroaching on medical laboratory testing resources, he said.

"Already there are positive signals coming out that such rapid testing is around the corner."