Swine flu cases are swelling again in Georgia and other southern states.
After months of quiet, is the "third wave" of the virus, long predicted by health officials, on its way here?
Maybe just a "third ripple," said Dr. Stephen Ostroff, director of the state health department's epidemiology bureau.
State health officials are closely watching what is happening in the South, Ostroff said. But they are not anticipating great numbers of people will fall ill here if the virus migrates north, as they did in the first wave last year at this time and the second wave last fall.
However, they said people in high-risk categories — particularly young adults and those with chronic health problems — still should get the vaccine.
"If we see activity, you could get the disease," Ostroff said.
Still, officials believe as many as half of all Pennsylvanians already are protected from it.
"A significant proportion of the population already was infected in those first two waves," Ostroff said. "Also, a sizable proportion of the population got vaccinated."
The third wave has emerged in three states reporting regional activity, Alabama, Georgia and South Carolina. A lesser, local level of activity is being reported in eight states, Arkansas, Louisiana, Mississippi, North Carolina, Tennessee, Virginia, Hawaii and New Mexico.
Ostroff said that recent wave mostly is affecting young adults, ages 25 to 45, who have health problems such as asthma, diabetes, heart issues or significant obesity.
"This is a somewhat different pattern than we saw last fall," he said, noting most of those earlier cases were in people ages 5 to 24.
The state has had only sporadic numbers of cases since Jan. 1, Ostroff said.
"If we are going to see increases," he said, "we will see them in the next couple of weeks. If we don't see them by then, even I will say it's not going to happen."