Flu season surges after sluggish start

ATLANTA —Cough, cold and flu purveyors this year endured an extremely slow start to the season in fourth quarter 2007, only to be rewarded with a highly active illness season coming through the second half of the season.

Through March 3, all states but one reported widespread instances of flu-like illnesses, marking the third consecutive week that more than 40 states reported widespread influenza.

“Nationwide, 5.7 percent of patient visits reported through the U.S. Influenza Sentinel Provider Surveillance Network were due to influenza-like illness,” Citi analyst Deborah Weinswig noted. “Though the flu activity is gradually declining, we believe that the continued strength in flu activity remains a significant positive for both Rx and front-end comps in February.”

Part of the reason behind the strong finish to this year’s flu season is that none of the prevalent flu viruses were included in this year’s influenza vaccine formula. Officials at the Food and Drug Administration are hoping next year not to repeat that scenario—last month an FDA advisory committee voted to revamp next year’s influenza vaccine.

Each year around this time, health officials make their best educated guesses as to which flu viruses may be present in the upcoming season and include three strains of flu virus in the vaccine to help protect people from getting sick. So the decision to wholeheartedly swap all three strains for three new strains is somewhat unusual, but may have been driven in part, because of the lack of protection associated with this year’s vaccine.

The new vaccine formula will include protection against the H3N2 strain Brisbane/10, a prevalent strain this year not protected against in the current vaccine formulation. The other strains chosen were an H1N1 Brisbane/59 and a Type B/Florida strain.

The fact that next year’s vaccine is expected to provide better protection against influenza isn’t the only factor that could drive vaccinations next season. A Centers for Disease Control and Prevention advisory committee last month recommended that influenza vaccine target populations include all children and young adults from 6 months to age 18.

The previous recommendation was for vaccination of children from 6 months to 5 years of age. The expanded recommendation is to take effect as soon as feasible, but no later than the 2009 – 2010 influenza season. That recommendation increases the number of children recommended for vaccination by about 30 million.

“This new recommendation should reduce the risk of influenza infections among children of all ages, and their consequent need for medical visits and missed time from school,” stated Anne Schuchat, director of CDC’s National Center for Immunization and Respiratory Diseases. Full implementation by fall 2009 at the latest will allow time to plan for the vaccination of this large group of children. However, immunization providers should begin efforts to offer vaccination to all children age 6 months through 18 years in the 2008-09 influenza season consistent with the recommendation that all persons who want to reduce the risk of contracting influenza or of transmitting influenza to others should be vaccinated.

Scientists at the National Institutes of Health may have discovered why the flu virus is more infectious in cold temperatures than during the warmer months.

And while that may mean fewer sick people in the winter, it may not mean fewer sales because it opens the door for new prevention products, study authors reported.

“Now that we understand how the flu virus protects itself so that it can spread from person to person, we can work on ways to interfere with that protective mechanism,”stated National Institute of Child Health Development director Duane Alexander.

Briefly, at cold temperatures, the virus’s outer covering hardens to a gel that shields the virus as it passes from person to person. With warmer weather, however, the protective gel melts to a liquid phase that apparently, isn’t tough enough to protect the virus against the elements, and so the virus loses its ability to spread from person to person.