LOWELL, Mass. -- City, school and health officials in the city of Lowell said Thursday morning that the two boys there who have swine flu are well on their way to recovery and may be able to return to school soon.

"They're almost through with their course of recovery, because it's about a seven-day experience and one child got sick a little earlier than the other so, we should hope to make a decision by tomorrow about when they can return to school," Lowell Health Director Frank Singleton said.

"It takes seven days to recover, so usually on the eighth day you're all right but we'll check in with their physician, and with the family obviously, to see if the symptoms have obviously ceased," Singleton said.

He said no one else who had any contact with the children or their family has been tested for swine flu because no one else has come down with any symptoms. He said it's unlikely they will now.

"By now, if it was going to happen it should have happened, but it hasn't," he said.

Lowell City Manager Bernie Lynch said there was no evidence the flu has spread in any way in Lowell, but all officials there will continue to monitor the situation closely.

"The health department has investigated and finds no reason to believe the virus was transmitted to anyone else," he said.

Lowell School Superintendent Chris Scott said there is a plan in place within the school system to deal with any possible outbreak but she said everyone needs to remain calm and keep the situation in perspective.

"I think at this time level heads are prevailing. People aren't pulling their kids out of school," Scott said.

She said the boys' mother, a school department employee, had not returned to work after returning from Mexico and still hasn't. She said no other students and no teachers in the Lowell school system have exhibited swine flu symptoms. As for parents, she said, no is overreacting.

Singleton said that may be because people understand that this strain of swine flu is relatively mild.

"It's also normal flu. It's not a deadly form of flu. If you come down with the flu, you come down with the flu. People do every year. So the fact that it's swine flu doesn't change the fact that this one, unlike what we're worried about, a very deadly strain like 1918, did not occur," Singleton said.

He said the main threat associated with this strain of the flu is that no one has any immunity to it, so there is the potential for it to spread rapidly and for large numbers of people to get sick.

"If it did, obviously there would be a major impact on commerce, on government," he said.

The boys' who contracted the virus on a trip to Mexico with their family have not been identified. They are 13 and 9 years old and attend the Immaculate Conception School in Lowell. They did not attend school after returning from their trip, but the younger brother did play in a couple of Little League games before he was tested.

The 9-year-old boy played a scrimmage game last Thursday night at Shedd Park and played in the season opener on Saturday, a source told NewsCenter 5.

Some neighbors remained concerned.

"I think we should have known," said Pam Lebranch, who lives a few doors down from the boys. She said her son Nick attends the same school.

"He didn't even want to go out yesterday. He was a little more concerned than I was. I said 'Nick, you know what? Whatever happens, happens. We can't prevent it and if it happens we'll go see the pediatrician right away,'" Lebranch said.

She said Immaculate Conception parents found out about the flu situation from the media, rather than school officials.

Gov. Deval Patrick said residents can get updated swine flu information by calling 211 or by logging on to the state's public health blog.

Massachusetts health officials said they have screened about 40 people, mostly children, for the virus across the state. Although state health officials said there is no vaccine that can specifically guard against the swine flu, Massachusetts has about 50,000 doses of flu vaccine on hand, and expects another 50,000 doses from the federal government.

"I do want the public to know that we are prepared, and we want the public to be prepared," Patrick said.

The state is also awaiting test results from two possible swine flu cases in Brockton.

The Massachusetts Department of Education on Wednesday recommended any school or child care facility with a confirmed case of swine flu in a student or a family member should strongly consider a temporary closure. The department also advised school staff and parents to develop a closure plan. Read DOE's Full Recommendations