Correction: Face masks to prevent transmission of respiratory infections: Systematic review and meta-analysis of randomized controlled trials on face mask use

• Hanna M. Ollila, 
• Markku Partinen, 
• Jukka Koskela, 
• John Borghi, 
• Riikka Savolainen, 
• Anna Rotkirch, 
• Liisa T. Laine