There is to be a four-week pause in the relaxing of Covid restrictions in Wales, the first minister, Mark Drakeford, will confirm on Friday.
More than half a million doses of vaccine are set to be deployed over the next month to try to head off a fresh wave of serious illness.
The latest figures show there are almost 490 cases of the Delta variant in Wales – accounting for more than four out of five new Covid cases in the country. Two thirds are not linked to travel or contact with another case, suggesting community spread.
Though Wales’ coronavirus case rate has risen steadily since the end of May and the positivity rate has more than doubled, it remains the lowest in the UK.
Drakeford said: “In the space of just a few short weeks, the Delta variant has entered Wales and quickly spread throughout the country. There is sustained and accelerating transmission in all parts of Wales. We are once again facing a serious public health situation.
“We have the lowest coronavirus rates in the UK and the highest vaccination rates for first doses. A four-week delay in relaxing restrictions could help to reduce the peak number of daily hospital admissions by up to half.”
Rules in Wales were last relaxed on 7 June and said outdoor events with up to 10,000 people were allowed to resume and other events, such as concerts, football matches and sporting activities, could recommence for up to 4,000 people standing and 10,000 people sitting. The regulations will be reviewed again on 15 July after being reviewed earlier this week.
Although there will be no substantive changes to the rules in the meantime, some small “technical amendments” are being made to the Covid regulations to make them easier to understand and apply for businesses.
The number of people who can attend a wedding or civil partnership reception or wake, organised by a business in an indoors regulated premises, such as a hotel, will be determined by the size of the venue and a risk assessment.
Clarifying small grassroots music and comedy venues will be able to operate on the same basis as hospitality venues, such as pubs and cafes.
Primary school children in the same school contact group or bubble will be able to stay overnight in a residential outdoor education centre.
Pilot events in theatre, sport and other sectors will also continue throughout June and July.
Public Health Wales said all health boards had reported cases.