More than 50,000 people have been vaccinated against measles in a major campaign to battle a growing epidemic.
The headline rate of measles in the worst-affected greater Swansea area, in South Wales, hit 1,105 this week, with 11 extra cases since Tuesday.
While the rate of increase is slowing, the two-day rise in one region is still more than the eight cases for the whole of Wales in 2010.
Public Health Wales (PHW) said 52,502 measles, mumps and rubella (MMR) jabs were given to people across Wales between the start of March and May 13.
Despite major progress protecting thousands against the disease, vaccination up-take remains too low among the worst-hit 10 to 18 age group.
About 50,000 people across Wales within that age group were without MMR protection at the start of the outbreak.
More than 15,000 have been vaccinated since the beginning of March but that still leaves 35,000 unprotected.
With so many of the crucial 10 to 18 age group still unprotected, further outbreaks of measles remain possible, PHW warned.
The headline rate of measles for the whole of Wales, since the start of November 2012, now stands at 1,292.
Concern about further measles outbreaks is highest in Gwent, which takes in Newport, where 100 cases have been notified this year.
Dr Marion Lyons, PHW director of health protection, said: “We would like to thank all the parents and young people who have taken advantage of opportunities to be vaccinated in GP surgeries, schools sessions and drop-in clinics.
“In the 10 to 18 age group we have vaccinated more than 15,000 people since the beginning of March, but this does leave us with more than 35,000 still needing vaccination, including just over 8,000 in Gwent.
“We continue to have concerns about this age group and would remind young people and their parents that measles can be very serious and even fatal.
“Now is not the time to be complacent and it is never too late to catch up on missed MMR doses.
“We are pleased to see that many parents who have refused the MMR vaccination for their children in the past are now coming forward and we would urge other parents to follow their lead.”
A major vaccination programme of weekend drop-in clinics will continue until May 24.
Unvaccinated young people and their parents are urged to take advantage of the opportunities to ensure they have measles protection.
On Saturday, drop-in clinics will be running from 10am to 4pm at Singleton and Morriston hospitals, Swansea, Princess of Wales Hospital, Bridgend, and Neath Port Talbot Hospital. No appointment is needed.
Aneurin Bevan Health Board is also holding a clinic between 11am and 3pm on the same day at the outpatients department of the Royal Gwent Hospital in Newport.
Vaccination sessions are also planned in Brecon and Newtown on Saturday May 25.
Dr Lyons added: “It is just a matter of time before a child is left with serious and permanent complications such as eye disorders, deafness or brain damage, or dies.
“The MMR vaccine is recommended by the World Health Organisation, UK Department of Health and Public Health Wales as the most effective and safe way to protect children against measles.”