The HSE's COVID-19 testing and tracing team is expecting a "very busy" September as schools reopen.
They're expecting a particular increase in demand for testing from the second week of September, a week after schools reopen.
Primary and secondary schools nationwide will be reopening over the course next 10 days, amid the ongoing Delta wave of COVID-19 infections.
Teenagers aged 12-15 are currently being vaccinated, although it's likely to be mid-late September before most people in the age group are fully vaccinated.
There have been calls for extra health and safety measures to protect primary school children from infection.
Meanwhile, up to 15,000 tests are currently being carried out at HSE testing sites each day - with roughly 70% of those self-referrals (either walk-ins or online bookings).
Around 10% of people are being referred by GPs, and the remaining 20% are close contacts of confirmed cases.
Ireland's positivity rate currently stands at 9% - up from 2.4% at the start of July.
Speaking on On The Record, Niamh O'Beirne - the head of the HSE’s test and trace programme - says testing is currently busy but “relatively stable”.
She said: “On a standard Monday-Friday, we’re running anywhere between 14-15,500 tests in our community testing sites. Yesterday was a busy Saturday with 12,500 tests done - very similar to last Saturday.
“Then you have testing going on the hospitals and private testing. There still are some days when you’re getting close to 25,000 [tests] on a given day.”
There are “very high positivity” rates from people who are booking their tests online - up to 33% at some sites.
She said: “It tells us people are using that channel who are symptomatic and feel they have been in contact with COVID.”
Contact tracing, meanwhile, shows around 20-30% of new cases are fully vaccinated - a number the HSE is expecting to increase as vaccination levels increase, in line with what has been seen in other countries.
Ms O'Beirne said: “People who do report to be fully vaccinated have milder symptoms.
"But it’s definitely something we expect to see rise as we see more vaccination - and as you know we have very good vaccination levels.”
She urged anyone who does have symptoms to come forward for testing, even if they've been fully vaccinated.
With the virus now spreading rapidly in the likes of New Zealand and Australia, concerns have been raised that the Delta variant may be leading to more outdoor transmission.
Ms O'Beirne said it can be “difficult to ascertain” where the virus is being transmitted in Ireland, as many events involve a mix of both indoors and outdoors.
She said more outbreaks do tend to be associated with the likes of sports, clubs, birthday parties, bars and retail as transmission levels rise.
She said there are "different positivity rates in different counties", and people need to make a personal decision about what’s safe for them.
Meanwhile, testing and tracing teams are preparing for a busy September.
Ms O'Beirne said: "We note what happened last September when schools began - not only do you have potentially COVID circulating, you also have other respiratory viruses circulating. That substantially increases the volume of testing.
“Last year, it didn’t necessarily have the same impact on positivity levels - there were a lot of children being tested, but they weren’t positive for COVID.
"This year, we go into a new school year with more cases.”
She said supports will be in place to help schools handle the likely increase in cases and demand for testing.
She also said antigen testing for close contacts will be looked at if testing demand increases, but currently they're still operating within their daily capacity for the ‘gold standard’ PCR test.