Two more Massachusetts residents have died from complications related to the H1N1 virus, health officials said Friday.

Special Section: H1N1

The deaths of a child under the age of 4 from Middlesex County and an adult aged 49 to 64 from Suffolk County have both been blamed on the virus, the Department of Public Health said. The adult did have underlying health conditions, officials said.

"We extend our condolences to the families of this child, as well to all the families who have lost loved ones," Massachusetts Public Health Director Dr. Lauren Smith said.

The two most recent deaths bring the total number of deaths blamed on the virus this fall to five statewide, and 17 for the entire H1N1 outbreak of 2009.

"We want to make sure that the public understands that influenza can be a serious disease. But recognize that we have always stressed the fact that for most people it is not a serious disease, but, clearly, it can be, and was tragically so in this case," Smith said.

Certain groups of people are at higher risk of complications for the H1N1 flu, the DPH said. These groups include children, young adults up to the age of 24, pregnant women and people with chronic underlying health conditions, such as asthma, diabetes and heart disease. These people should call their doctor immediately to discuss appropriate treatment if they develop a fever with a cough, sore throat or runny nose, the DPH said.

People are encouraged to get vaccinated against both H1N1 and seasonal flu; wash hands frequently with soap and warm water or use an alcohol-based hand sanitizer; cover their coughs and sneezes with a tissue, or cough or sneeze into their inner elbow and not into their hands. The DPH also advises sick people to stay home for at least 24 hours after their fever goes away.