4 ms·
Double masking also seems very effective: https://www.cdc.gov/mmwr/volumes/70/wr/mm7007e1.htm https://www.cdc.gov/mmwr/volumes/70/wr/mm7007e1.htm
by prox 5y ago
Double masking also seems very effective:
https://www.cdc.gov/mmwr/volumes/70/wr/mm7007e1.htm https://www.cdc.gov/mmwr/volumes/70/wr/mm7007e1.htm