As the science and the virus evolves, so do the policies and recommendations. While all masks provide some level of protection, the CDC now recommends using the most protective mask you are able to because the Omicron variant is even more infectious than earlier variants.
The CDC also updated recommendations on N95s based on supply. When there was limited nationwide supply, CDC recommended prioritizing N95 respirators for healthcare workers, but now N95s and KN95s are widely available.
Added January 18, 2022