The unanimous absence of bearish ratings and the presence of 10 positive (bullish or somewhat bullish) ratings out of 12 suggest a strong analyst consensus on the potential for Merck's stock price to rise. The significant increase in the average price target also reflects a positive adjustment in the stock's valuation by the analysts. Given this information, the short-term impact on Merck's stock price is likely to be positive as the market reacts to the analyst ratings.