Shares of Teladoc Health Inc. /zigman2/quotes/207420252/composite TDOC -6.58% and One Medical-parent 1Life Healthcare Inc. /zigman2/quotes/205852497/composite ONEM -7.47% extended losses Thursday, in the wake of Amazon.com Inc. /zigman2/quotes/210331248/composite AMZN -2.73% announcement on Wednesday that it will be rolling out its Amazon Care telemedicine program nationwide. Teledoc's stock slumped 2.3% in afternoon trading, after shedding 4.4% on Wednesday, while 1Life shares slid 4.1% after losing 0.8% the day before. "Clearly, competition has increased, and we do not discount Amazon's potential for success," Canaccord Genuity analyst Richard Close wrote in a note to clients. Of the companies he covers, Close said competition will be greatest for Teladoc and One Medical, but noted that it doesn't mean investors should give up on the companies. "In the past, rumblings of Amazon's healthcare services interests have been buying opportunities," Close wrote. He recommended his buy ratings on Teladoc and 1Life, saying he does not believe the Amazon Care news has materially damaged the near-term opportunity for solid growth. "There should be ample opportunities for sustained growth going forward," he wrote. Teladoc's stock has lost 5.4% over the past three months and 1Life shares have ticked up 0.4%. In comparison, Amazon's stock has slipped 3.8% over the same time, while the SPDR Health Care Select Sector ETF /zigman2/quotes/205918244/composite XLV +0.44% has edged up 2.2% and the S&P 500 /zigman2/quotes/210599714/realtime SPX -0.67% has gained 6.7%.