LOS ANGELES (KABC) -- After Philadelphia became the first major U.S. city to re-implement indoor masking this week, the change is leaving some in the city frustrated.
"I wish the city would pick something and stick to it," one resident said.
Dr. John Brownstein, an epidemiologist with Boston Children's Hospital, said, "the idea is that a mask policy can help reduce spread, reduce the numbers of cases and ultimately keep students in-person learning, which is so critical, especially this far into the pandemic."
In Los Angeles County, public health officials are beefing up efforts to protect the most vulnerable by improving access to second booster shots.
The focus is on residents and employees in skilled nursing facilities. Health officials are reaching out to nearby pharmacies and sending mobile teams to help distribute COVID-19 vaccines.
Plus, airline executives and Republican lawmakers are urging the Biden Administration to let a federal requirement to wear face masks on airplanes and public transportation expire on April 18.
But with rising cases of the omicron subvariant in 27 states, the Centers for Disease Control and Prevention is considering extending it.
"There is a concern for new variants in the coming months," said Brownstein.
Public health experts have grown concerned over the lack of reporting of at-home test results leading to an undercount of the true number of COVID cases in the U.S.
The National Institutes of Health and the Association of Public Health Laboratories are working with home test manufacturers and public health authorities to make reporting cases easier and more efficient.
Experts say anyone who has COVID symptoms - even just a sniffle - should get tested and report it to their doctor.