https://www.cdc.gov/mmwr/volumes/70/wr/mm7010e3.htm
This study says they help but read the all the way to the end when they admit it doesn't help at all. Very tricky in their wording but it is still in their own words that
https://www.cdc.gov/mmwr/volumes/70/wr/mm7010e3.htm
This study says they help but read the all the way to the end when they admit it doesn't help at all. Very tricky in their wording but it is still in their own words that