Health chiefs say they 'continue to be concerned' at the number of cases of measles in the Swansea and Neath Port Talbot areas.
Nearly 200 people have been diagnosed since the outbreak started in November, with 20 new cases in the last week alone.
More than 30 schools and nurseries have been affected so far.
Public Health Wales says it is working closely with Abertawe Bro Morgannwg University Health Board to combat the outbreak.
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Cloudy and damp evening and night with low cloud giving hill fog and patchy drizzle
A mostly cloudy and murky day with widespread hill fog and outbreaks of rain.
Official figures show areas of Caerphilly, Rhyl, Wrexham, Rhondda Cynon Taf and Bridgend to be the most deprived in Wales.