?Corona Virus: When will the crisis end and life return to normal

The world is closed: places that were bustling with the hustle and bustle of daily life are ghost cities after massive restrictions - from home quarantine and school closures to travel restrictions and the ban of public gatherings.

This came in response to an outbreak of a fatal disease. But when will the crisis end? And when can we continue our lives?

British Prime Minister Boris Johnson believes that the UK may "reverse the course" of the disease outbreak within the next 12 weeks.

But even if the number of cases begins to decline in the next three months, we will remain far from the end of the crisis.

It may take a long time to stop the spread of the virus - and possibly years.

It is clear that the current strategy of isolating large parts of society is not sustainable in the long run, as social and economic harm will be disastrous.

What countries need is an "exit strategy" - a way to lift restrictions and return to normal.

However, the Corona virus will not disappear.

If the restrictions that hinder the spread of the virus are lifted, the number of cases will inevitably increase.

"We have a huge problem with regard to the disease elimination strategy and how to achieve this," says Professor Wall epidemiology and infectious diseases at the University of Edinburgh, adding, "Not only in the UK, there is no country with an exit strategy."

It is a major scientific and social challenge.

There are three main ways to get out of this mess:

Vaccine development

Develop enough people to be immune through infection

Or change our behavior / society permanently

These are ways to limit the virus's ability to spread.

Vaccine development: at least 12-18 months.

The vaccine is supposed to give the person immunity so that he does not get sick if exposed to the virus.

The virus cannot spread if enough people are immunized, about 60 percent of the population, from the concept known as "herd immunity".

The first person got a test vaccine in the United States this week, after researchers were allowed to break the usual rules of animal testing first.

Research is being done to develop vaccines at an unprecedented speed, but there is no guarantee that they will succeed.

The vaccine can be ready after 12 to 18 months, if everything goes smoothly. This is a long time if we look at the unprecedented social restrictions currently imposed.

"Waiting for the vaccine should not be considered a strategy, this is not a strategy," Wallhouse told BBC.

Natural immunity development - after at least two years

The UK's short-term strategy is to reduce the number of injuries as much as possible by not depleting hospitals - as when intensive care beds are exhausted, deaths will rise.

Once the cases are contained, this may allow some procedures to be lifted for a while - until the cases rise again then we need a new round of restrictions.

"Setting absolute time limits for things is not possible," said Sir Patrick Valance, the UK's chief scientific advisor.

This can lead to the development of what is known as "herd immunity" when more and more people become infected with the virus.

But that could take years, according to Professor Neil Ferguson of Imperial College University in London.

Ferguson said: "In the end, if we continue that for more than two years, then perhaps a sufficient part of the community may have been infected, in a manner that provides a certain degree of societal protection."

But there is a question mark about whether this immunity will last for a long time. Other corona viruses lead to a very weak immune response, and people can catch the same virus several times in their lives.

Alternatives - No clear endpoint

"The third option is permanent changes in our behavior that allow us to maintain low transmission rates of infection," said Professor Wallhouse.

This may include maintaining some procedures that have been put in place, or testing and isolating patients strictly to try to contain any outbreaks.

Developing medications that treat the Covid-19 virus can help other strategies succeed.

These medications may be used as soon as people show symptoms, in a process called "transport control" to prevent them from passing infection to others.

It may be useful in treating hospital patients to make the disease less lethal and reduce stress on intensive care departments. This will allow countries to deal with more cases before the need to reactivate home quarantine.

It is also beneficial to increase the capacity of the intensive care units, as this will help in dealing with the outbreak of patients on a larger scale.

I asked the UK's chief medical advisor, Professor Chris Whitetti, what is the exit strategy from the Corona Virus crisis.

"In the long run, it is clear that the vaccine is one way out of this, and we all hope that this will happen as soon as possible," he said.

He expected that "science will find solutions worldwide."