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* FTSE 100 down 0.1%, FTSE 250 flat

* GSK slides as US CDC narrows age recommendation for RSV shots

* Burberry trades without dividend entitlement

June 27 (Reuters) - UK stock indexes were largely muted on Thursday as investors digested a slew of corporate updates, while caution around U.S. and British economic data further dampened sentiment.

The benchmark FTSE 100 was down 0.1%, while the mid-cap FTSE 250 was flat by 0720 GMT.

The pharma and biotech sector was impacted by a 6.5% drop in drugmaker GSK after the U.S. CDC on Wednesday narrowed its recommendation for the use of respiratory syncytial virus vaccines in older adults this year and held off on recommending their use for adults under the age of 60.

On investors' radar this week is the U.S. personal consumption expenditure (PCE) numbers, due on Friday, which could influence the Federal Reserve's stance on interest rate cuts this year.

Meanwhile, UK gross domestic product (GDP) figures this week could potentially add to the Bank of England's confidence to cut rates in August.

Investors also appeared cautious ahead of Britain's July 4 parliamentary elections.

Precious and industrial metal miners inched 1.1% and 0.8% lower respectively as gold and copper prices steadied near weekly and monthly lows.

The automobile and parts sector dropped 1.5% after industry data showed Britain's car output had dropped 11.9% year-over-year in May, declining for the third straight month.

Accessories retailer Burberry slipped 3.2% as the company traded without entitlement to its latest dividend payouts. (Reporting by Purvi Agarwal in Bengaluru; Editing by Sohini Goswami)