Two more children have died this past week from flu-associated illnesses, bringing this season’s total to 20, according to the Centers for Disease Control and Prevention’s new FluView report.

CDC officials said while flu activity remains high in most states, some areas are actually seeing a decrease in activity, such as the South and Southeast, which were particularly hit hard early on in the season.

According to the agency, the proportion of outpatient visits for influenza-like illnesses (ILI) this past week was at 4.3 percent, which is still above the national baseline of 2.2 percent. New York City and 24 states are experiencing high ILI activity, and 16 states are reporting moderate ILI activity.

Forty-seven states are reporting widespread flu activity – so it is still urgent to get vaccinated if you have not yet received the flu shot. Those particularly at risk are children, senior citizens or those with an underlying health condition.

Last week, the agency said it is likely the increased flu activity will continue for a while.  Based on the last 10 flu seasons, ILI remained at or above baseline for about 12 weeks – and up to 16 weeks during the 2005-2006 season. ILI remained above baseline for 19 weeks during the 2009 H1N1 pandemic.

Vaccine shortages
Officials said there may be a shortage of flu vaccines in some areas of the country. However, if you call around to different flu shot providers, you should be able to find a place that has the vaccine.

"People who haven't been vaccinated and want to get the vaccine may have to look in several places for it," said Tom Skinner, a spokesman for the CDC.

The vaccine remains the most effective form of prevention from the virus. Health officials said the vaccine is about 60 percent effective, and this year’s vaccine is well-matched to the viruses that are circulating.

Manufacturers projected 135 million doses of the vaccine, and 128 million doses were distributed as of the first week of January.

Sanofi SA, the largest flu vaccine provider in the United States, said on Thursday it had sold out of four of the six different dosages of Fluzone seasonal flu vaccine due to unanticipated demand. The vaccine is made in different sized vials and pre-filled syringes.

"At this point we are not able to make any more vaccine because we are gearing up for next year's vaccine," said Michael Szumera, a spokesman for Sanofi. Because flu strains mutate, vaccine makers must reformulate seasonal flu vaccine every year.

Henry Schein Inc, the nation's largest distributor of flu vaccines to physicians' offices, said it has vaccine available from Novartis for its customers immunizing patients four years old and older.

However, it said "we do not have the pediatric vaccine for children aged six months to four years old due to its unavailability from the manufacturer, Sanofi."

Roche Holding AG has a shortage of the liquid form of Tamiflu, given to children who already have the flu to slow or stop symptoms.

Doctors are recommending that if you start to see flu-like symptoms, including cough, fever and fatigue, you should start to take anti-virals immediately, and not wait for a positive test to come back.

Reuters contributed to this report.