This year’s influenza vaccine hasn’t stopped a spike in flu cases on campus, according to a Binghamton University health official.

“We have been averaging about 50 students per week over the last two weeks,” said Dr. Michael Leonard, medical director for BU’s Health Services. “Our common weekly influenza number during the flu season is 10 to 20.”

The vaccine’s “inefficacy” to the ever-shifting strains of the virus caused the jump in numbers, which haven’t been this high since December of 2003, Leonard said.

The vaccine is made six to nine months in advance of the season, forcing scientists to guess which strains will be dominant. This year scientists formulated a vaccine with antigens to fight the strains A(H1N1), A(H3N2) and B. But the vaccine has a 40 percent efficacy rate this year, as opposed to its usual 70 percent rate.

Strains of the A(H1N1) virus were found in early January, but the vaccine protected against these infections.

Toward the end of January, A(H3N2) and B viruses were found, but “these unfortunately were not well-matched against the vaccine and the coverage was less than ideal,” Leonard said. “We have seen students with influenza who have received the vaccine.”

The number of cases jumped even though Health Services gave 665 vaccine injections this year — 30 more than last year. But Leonard said he’s not surprised.

“This year’s influenza vaccine’s inefficacy was an unfortunate although not uncommon development,” he said. “Next year’s vaccine will be adjusted to meet this ‘shift’ in the virus.”

Getting a yearly vaccination is the best way to prevent the flu, according to the Centers for Disease Control and Prevention (CDC), which is part of the U.S. Department of Health and Human Services. But there are other methods to stop the spread of the flu, a contagious respiratory illness.

Students can keep their immune systems strong by eating healthy, drinking plenty of fluids and getting enough sleep and rest.

“One should be cautious with alcohol and avoid smoking,” Leonard said.

Since influenza is transmitted by touch, students should always wash their hands and keep their hands away from their faces.

In terms of medicine, ibuprofen (Advil or Motrin) and acetaminophen (Tylenol), should be “used frequently to reduce the fever and body ache,” Leonard said. “Decongestants and cough syrup can be used.”

Symptoms usually subside in three to five days.

“If symptoms persist past this or intensify, then it is important to see a health care provider,” he added.

For more information, including a weekly report on the intensity of the flu, check cdc.gov.