1m versus 2m: What experts say about social distancing

The debate rages on here over whether the official public health approach on social distancing to help prevent Covid-19 infection should be for people to stay one metre or two metres apart.

The World Health Organization (WHO) recommends that people stay at least one metre and ideally two metres from one another to help limit transmission of the virus.

The European Centre for Disease Prevention and Control (ECDPC) recommends that people stay one metre or more away from people infected with the virus.

Read: No change to 2m social distancing rule yet, confirm ministers

In the early stages of the crisis here, back in mid March, the advice in Ireland was to keep at least one metre and ideally two metres from one another.

The official public posters set this out as the guidance.

Later, the National Public Health Emergency Team (NPHET) settled on two metres in its interpretation of the ECDPC advice.

I raised this very point at a press briefing at the Department of Health several weeks ago. Even then, people were asking - was it one or two metres?

According to the advice today on their respective websites, one metre is acceptable for both the WHO and the ECDPC.

The ECDPC advice about two metres relates to what is defined as a "close contact" for contract tracing purposes.

People will have their own view on whether one or two metres is best practice.

An abundance of caution will be cited by some for the two metre rule. Others argue it is too restrictive and not based on an official WHO/ECDPC position.

However, the difference between one and two metres could be critical to the economic survival of some Irish businesses which are hoping to reopen soon.

In public health terms, officials have to take a view on international advice, home expertise and then their interpretation of the available advice.

As with the virus itself, it seems nothing is quite clear cut. Then it comes down to best judgment.