Every county in the Birmingham metropolitan area except Blount has been moved into the high-risk category for COVID-19 transmission.

Jefferson County’s positivity rate has been rising and now stands at 25%, according to the Alabama Department of Public Health, and the county has had an average of 291 new cases a day for the past seven days. Hospital admissions in the county are up somewhat, with 10 more patients over last week, for a 2% increase.

The swath of counties with high transmission risks means residents need to exercise more care, including making sure their vaccinations are up to date and wearing masks if they are at a high risk from the virus, said Dr. Wesley Willeford, Jefferson County Health Department’s medical director of disease control. He said health officials see no need now to issue mandates as they did in 2020.

Willeford said part of the reason for the rising cases is that immunity people developed during the winter peak of the virus began to wear off by mid-May, which is when the transmission level began to increase. Willeford said five months is about the average time for immunity to wear off after an exposure or vaccination.

“The decline (in immunity) as well as new variants occurring seemed to coincide with the beginning of the increase in cases,” he said.

Wes Stubblefield, northern district medical officer with the ADPH, added that the increase in cases also can be attributed to more people getting together, particularly indoors.

The question is how long transmission rates will continue to rise and when they will peak, which Willeford predicted would be in a month to six weeks.

“We don’t know, but we will keep seeing it for awhile, but at least we are not seeing severe forms of the virus, Stubblefield said.

He said the Food and Drug Administration next week is scheduled to discuss the possibility of a new vaccine for the original virus and a second one specific to the omicron variants.

Counties besides Jefferson with high transmission rates are Baldwin, Bibb, Cullman, Escambia, Henry, Madison, Shelby, St. Clair and Walker, according to the ADPH.

Statewide, there had been an average of 1,581 new COVID cases reported each day over the past 14 days as of Thursday, for a 55% increase over the period, according to the Centers for Disease Control.

Stubblefield said there are 350 patients hospitalized with COVID across the state, but he added, “That is just a fraction. when the number was once was up to 1,500 a day.”