- These reports are produced by the Central Shenandoah Health District and provide information on the 2009/2010 influenza season.
Flu seasons are unpredictable in a number of ways, including when they begin, how severe they are, how long they last and which viruses will spread. There were more uncertainties than usual going into this flu season (2009-2010), because of the emergence of the 2009 H1N1 influenza virus (previously called "novel H1N1" or "swine flu"). This virus caused the first influenza pandemic (global outbreak of disease) in more than 40 years.
Although influenza activity has declined recently, additional waves of influenza activity due to 2009 H1N1, seasonal influenza viruses, or both, may occur later this influenza season. Flu season can last as late as May. Even if the U.S. doesn't experience a sharp increase in influenza activity during the remaining winter or spring (another "wave" of influenza), continued low level circulation of influenza viruses may continue during this time.
2009 H1N1 viruses are spread from person to person through respiratory droplets (coughing or sneezing) and symptoms appear similar to the seasonal flu:
While most people who have been sick have recovered without needing medical treatment, hospitalizations and deaths from infection with this virus have occurred. About 70 percent of people who have been hospitalized with this 2009 H1N1 virus have had one or more medical conditions previously recognized as placing people at “high risk” of serious seasonal flu-related complications. This includes pregnancy, diabetes, heart disease, asthma, and kidney disease.
There are still uncertainties surrounding the rest of this flu season, including the possibility of the circulation of seasonal influenza viruses and ongoing circulation of 2009 H1N1 viruses. In past pandemics, flu activity has occurred in waves and it’s possible that the United States could experience another wave of flu activity. In addition, sporadic cases of influenza may also be detected in the summer.
The CDC released survey results on H1N1 interim vaccination rates through January. Virginia exceeded the national median as well as states in our region that included Delaware, the District of Columbia, Maryland, Pennsylvania and West Virginia. The Virginia Department of Health headed up the vaccination effort, combining the resources of both the private sector and that of the state’s local public health departments. More than 3,000 private doctor’s offices, hospitals, pharmacies, clinics and retail outlets have participated in getting H1N1 vaccine out to Virginians in a historic partnership.
“We are very grateful for our many strong partnerships with the medical community and with the many volunteers who worked tirelessly to vaccinate school-age children, those in high-risk groups and all other segments of the population,”
State Health Commissioner Karen Remley, M.D., MBA.
VDH data shows that 120,000 more Virginians have been vaccinated in February and March. Looking ahead, VDH recommends that anyone still unvaccinated get an H1N1 flu vaccination this spring. That should also provide a “jump start” for next fall’s flu season.
Public health officials continue to encourage individuals who have not yet been vaccinated, against both 2009 H1N1 and seasonal flu, to do so.
Every winter in the United States we prepare for possible seasonal epidemics of influenza A and B. Influenza A can be further sub typed based on two proteins on the surface of the virus; Hemagglutinin (H) and Neurminidase (N). The typical 
seasonal vaccine will include two influenza A strains (H1N1 and H3N2) and one influenza B strain.
This flu season (2009-2010), has had more uncertainties than usual because of the emergence of a new 2009 H1N1 (Swine) flu virus.
The seasonal strain of flu has not been widely circulated in comparison to past flu seasons, but timing can be uncertain. In past years, seasonal flu activity typically did not reach its peak in the U.S. until January or February, but flu activity has occurred as late as May. So it is not known when or if flu activity will increase, when it will be most intense (peak), what viruses will circulate, or how long the season might last.
Each year, approximately 5-20% of the general community will become sick with influenza. In the United States, influenza causes an estimated 200,000 hospitalizations per year and 36,000 deaths. At risk groups for serious complications from seasonal influenza include the elderly, young children, and people with certain health conditions
One of public health’s main goals is to slow community transmission of 2009 H1N1.
Interventions to avoid contracting an influenza virus:
The single best way to prevent an influenza infection is to get vaccinated. This 2009/2010 influenza season will have two influenza vaccine types; seasonal and 2009 H1N1. Each type has differing priority groups, time tables, and recommendations.
Seasonal influenza vaccine contains three influenza viruses-one seasonal A (H3N2) virus, one seasonal A (H1N1) virus, and one seasonal B virus. The viruses in the vaccine change each year based on international surveillance and scientists' estimations about which types and strains of viruses will circulate in a given year.
Generally everyone is encouraged to get a seasonal influenza vaccine. There are some people should not be vaccinated without first consulting a physician. They include:
The seasonal vaccine does not protect against the 2009 H1N1 influenza strain. People are still encouraged to receive both the seasonal and the 2009 H1N1 vaccine. The 2009 H1N1 virus continues to circulate throughout Virginia and health officials are encouraging those who have not yet received their vaccine to do so. The local health departments in the Central Shenandoah Health District have a supply of 2009 H1N1 vaccine that is available to the public at no cost.
Next flu season, it will only be necessary to get one flu shot. The viruses used in making seasonal flu vaccines are chosen each year based on information collected over the previous year about which influenza viruses are spreading and what vaccine viruses would offer the best protection against circulating viruses. The three vaccine viruses are chosen to maximize the likelihood that the main circulating viruses during the upcoming flu season will be well covered by the vaccine. That means that, barring some unforeseen circumstance, this fall, most Americans will be able to return to having one flu vaccine to protect them against the major circulating flu viruses. As is always the case with seasonal vaccine, younger children who have never had a seasonal vaccine will still need two doses.
The flu vaccine protects against the three main flu strains that research indicates will cause the most illness during the flu season. This year’s influenza vaccine contains three new influenza virus strains:
The 2010-11 influenza vaccine can protect you from getting sick from these three viruses, or it can make your illness milder if you get a related but different influenza virus strain.
The following documents are in .pdf format. 
Pandemic 2009 H1N1 Vaccination Campaign:
2009 H1N1 Vaccination Coverage in Virginia
PowerPoint: H1N1 – The Virginia Experience
The General Public:
Virginia Department of Health
Center for Disease Control and Prevention
World Health Organization
Medical Professionals:
CDC Guidance Documents for Health Care Providers
VDH Medical Provider’s Webpage
Schools:
Additional Web Resources: