The World Health Organisation (WHO) is warning that there is still a high risk of a resurgence in COVID-19 this autumn.
The alert comes as case numbers, hospitalisations and deaths associated with the virus are declining across Europe, including in Ireland.
There are 59 patients being treated in hospital for the virus here, the lowest level in nearly nine months.
Meanwhile, fans will return to a number of sporting events this weekend, while Ireland's first live gig since the start of the pandemic took place in the Iveagh Gardens in Dublin last night.
As societies across the EU further ease restrictions, the WHO urged people to exercise caution this summer.
Dr Margaret Harris, spokesperson for the WHO, told Newstalk Breakfast that we need to continue following the same public health measures even as more people are vaccinated.
"People instinctively when the weather gets better and everything starts to look a lot better say, well now we can relax," she said.
"But the critical thing is to relax with care, which sounds a bit crazy but is very doable.
"As the measures come down, and people have earned the right to open up societies and find a way to live carefully, keep the three Cs in mind - the avoiding of crowding, the avoiding of being in closed, confined spaces, and avoiding close contact while being in those enclosed spaces."
Dr Harris said compared with the original strain of COVID-19, the delta variant originating from India is between 70 and 100% more transmissible
She explained: "If you're next to somebody who's got it, your chances are increased considerably.
"But also what that means is the same measures that protected you in the past from the less transmissible [strain] will also protect you from this one.
The WHO is advising Government's to begin sequencing the cases, which involves looking at the genetics of the viruses that are circulating.
This will allow them to gauge what variants are circulating in society and coming into the country.
"This summer, act as if the transmission is definitely there because the threat of that still remains," Dr Harris advised.
"The difference [this year] is that we've got the vaccination but the vaccination doesn't end the pandemic, the pandemic will end when we have eliminated the circulation of the virus from our communities."