
Chief Medical Epidemiologist Mini Kamboj
Getting vaccinated is the best way to protect yourself against COVID-19. Vaccines are extremely effective at protecting you against severe illness and hospitalization, and they also reduce the spread of COVID-19.
On February 12, 2023, New York State ended its mandate requiring all staff, patients, and visitors wear masks in healthcare settings. The state now directs healthcare organizations to maintain their own mask policies based on the rate of COVID-19 transmission in their community and the risk of severe disease among their patients.
Our visitor policy has information about when you need to wear a mask at MSK.
A well-fitting mask remains an important tool to reduce the spread of COVID-19. Masks protect you from getting infected and passing the virus to people around you.
Mini Kamboj, Chief Medical Epidemiologist at Memorial Sloan Kettering Cancer Center, explains what you need to know about what type of mask to wear and when.
When to Wear a Mask
You should follow the rules and guidance in your community for situations including businesses, schools, transportation hubs, and hospitals.
In all indoor and outdoor settings, it’s especially important for you to wear a mask if:
- You are immunocompromised
- You are not fully vaccinated
- Physical distancing is not possible
- COVID-19 rates are high where you live (see here for a map from the CDC)
No matter what, it’s smart to stay at least 6 feet apart from people who don’t live in your household and to wash your hands frequently for at least 20 seconds.
Types of Masks
Any mask is better than no mask. When wearing a mask, it should fit snugly and should cover your nose and mouth.
There are different masks that offer different levels of filtering protection against virus particles:
- N95 masks (highest filtering capacity)
- KN95 masks
- Medical-grade mask, also called a procedure mask or a surgical mask
- Cloth mask (lowest filtering capacity)
When to Wear a KN95 or N95 Mask
A well-fitting medical-grade face mask offers good protection in most situations, especially when everyone around you is wearing a mask properly.
N95 masks (also called respirators) are better at filtering out very tiny particles. These masks are regulated by the National Institute for Occupational Safety and Health (NIOSH), which is part of the Centers for Disease Control and Prevention (CDC). For hospital workers, they must be fitted to ensure a proper seal. It’s important to know that continuously wearing an N95 can be challenging for most people who are not used to these masks, because they can make breathing and talking more difficult.
The best mask is a medical-grade mask that will always fit your face snugly to cover your nose and mouth. It should be comfortable to wear so you don’t constantly feel the need to readjust it and, in that process, risk exposure to COVID-19.
In general, you can choose to wear a KN95, an N95, or two medical-grade masks in situations where you need extra protection. Examples of these situations include:
- If you are caring for someone with COVID-19
- If you are in a crowded indoor setting when physical distancing is not possible
- During extended travel, including on a train or bus
- When vaccination status of those around you is not known and people around you are not wearing a mask
You can choose to wear a KN95, an N95, or two medical-grade masks if you are at increased risk of severe COVID-19 because you are elderly, have a weakened immune system, or have another underlying medical condition (see here for more information from the CDC about who is at increased risk).
There is a lot of information on the CDC website about what you need to know before buying an KN95 or N95 mask to verify its authenticity.
Why You Should Wear a Mask
Over 200 million Americans have been fully vaccinated against COVID-19, which means tens of millions of people are still not vaccinated. When a lot of people are unvaccinated, COVID-19 can continue to spread, including to those who are vaccinated.
In addition, the vaccine’s protection may decrease after several months, which is why you should get a booster shot. People with a severely weakened immune system also need an additional dose to strengthen their defenses against COVID-19.
Masks provide an extra layer of protection for all of us.
February 14, 2023
Additional Resources
- Pfizer-BioNTech (Comirnaty®) COVID-19 Vaccine Fact Sheet for people age 6 months through 4 years
- Pfizer-BioNTech (Comirnaty®) COVID-19 Vaccine Fact Sheet for people age 5 through 11 years
- Pfizer-BioNTech (Comirnaty®) COVID-19 Vaccine Fact Sheet for people age 12 years and older
- Moderna (Spikevax™) COVID-19 Vaccine Fact Sheet for people age 12 years and older
- Johnson & Johnson/Janssen COVID-19 Vaccine Fact Sheet for people age 18 years and older
- Novavax COVID-19 Vaccine Fact Sheet for people age 18 years and older