Although Covid-19 case numbers continue to slowly decrease, they remain higher than projected for the beginning of March.

Today, 687 new cases were reported by NPHET. One death, which occurred in January, was reported today.

Here are five things we learned from today's Covid-19 briefing.

Behaviours: Weariness yet perseverance

Prof Pete Lunn, ESRI head of behavioural research, said there is a big difference between what people think and how they behave.

The latest studies show that while people are finding it tough to stick to the restrictions, the large majority (79%) believe that preventing the spread of Covid-19 is more important than the burden of restrictions. Just 10% disagree.

Presently, half the adult population does not meet up with anyone outside their household over a 48-hour period, with less than one quarter meeting up with three or more.

Antigen testing

NPHET will be analysing the data on antigen testing, said Deputy Chief Medical Officer Dr Ronan Glynn, adding that the HSE is looking at the entirety of its testing capacity.

There is research ongoing on this type of testing under the chair of Prof Mark Ferguson, he said, and when it is reported, NPHET will be considering the findings.

Retrospective contact tracing

The HSE is planning to reintroduce retrospective contact tracing as soon as it is feasible, said Dr Glynn.

"The plans are in place" but he cannot say when that will kick in.

Retrospective tracing would give a better picture about where cases of the virus originated.

Travel rules: Why 5km?

The idea behind the 5km rule is to limit the spread of the virus between communities and to keep the number of people an infected person can come into contact with low.

"There's no scientific rationale underpinning 5km versus 4km or 6km. But there is a very clear public health rationale for asking people to stay at home and for setting a parameter which facilitates a clear understanding of what we're asking people to do."

They felt that, looking back, last year's 2km rule was overly restrictive.

Some public health measures to last

Dr Glynn said he thinks there will still be public health measures by the end of the year, but he is hopeful that we will be closer to what we considered 'normal' before the pandemic.

We need to keep up the vaccine roll-out, and avoid any issues arising with variants along the way to get to that point.

Hopes around vaccination by June

On vaccines, Dr Glynn said they are "hopeful that up to 80% of the adult population will have received at least one dose by the end of June".

"We're not looking into a void like we were this time last year or like we have any point up to a couple of months ago when the first vaccines were approved," he said.

"Hopefully, we are not that far away from a point where we can have much less focus on some of these measures, and hopefully we'll be seeing much lower levels of hospitalisation."