Dr. William Mercer said it is anyone’s guess as to whether a third wave of the swine flu will occur this season. During a regular Ohio County Board of Health meeting Tuesday, Mercer, health officer, said Ohio County has not had any reported cases of the H1N1 virus lately. “We figure there’s maybe a 50-50 chance there will be a third wave,” Mercer said, noting in 1957-58 there was a third wave of the Asian flu after the holidays. “We’re still preparing for it, we’re still recommending people get the vaccine. We seem to have plenty now. And when we have plenty, that’s when interest dies down,” Mercer added. The health department continues to hold swine flu vaccination clinics Mondays, Wednesdays and Fridays. And some local physicians, like Mercer, are offering the vaccine. Mercer noted he has many elderly patients wanting the H1N1 vaccine. Meanwhile, the seasonal flu has yet to hit the region, but cases of the norovirus — known by most as the stomach flu — already are occurring, he said. The virus impacts the gastrointestinal system and causes nausea, vomiting, diarrhea, fever and chills, aches and tiredness. Symptoms usually last one to two days. “I was hoping we could avoid a big (gastro-intestinal) episode this year. But maybe this will run its course shorter,” Mercer said. “If you’re elderly, you can get dehydrated pretty quick and have some other problems. There is no vaccine for that.