The flu season is just beginning
In the United States, the flu season typically spans from December to February. About 25,000 people die each year in the US from flu-related complications. The latest statistics from 2011 indicate 53,826 people died from influenza and pneumonia. The US Centers for Disease Control and Prevention (CDC) has designated December 7-13th as National Influenza Week to emphasize the public health need for flu vaccinations as we enter the peak flu season. Availability of the flu vaccine should be widely accessible, and 7 influenza vaccine manufacturers are projecting around 155 million doses of influenza vaccine will be available this year. The 2014-2015 influenza vaccine will protect against at least 3 strains of flu (trivalent vaccine), and an additional vaccine will be available that will also protect against a 4th strain (quadrivalent vaccine). All of the 2014-2015 influenza vaccines will protect against the following 3 strains:
- A/California/7/2009 (H1N1) pdm09-like virus
- A/Texas/50/2012 (H3N2)-like virus
- B/Massachusetts/2/2012-like virus
The quadrivalent vaccine will also add protection against additional B virus: B/Brisbane/60/2008-like virus.
For those with a fear of needles, the the U.S. Food and Drug Administration (FDA) approved on August 15, 2014, the use of a jet injector device (the PharmaJet Stratis 0.5ml Needle-free Jet Injector) for delivery of a specific trivalent flu vaccine (AFLURIA® by bioCSL Inc.) for individuals ages 18 to 64. It uses a high-pressure, narrow stream of fluid to penetrate the skin rather than a needle.
The CDC recommends that all children older than 6 months receive a flu vaccine. This year, the CDC is advocating that healthy children 2-8 years old receive the nasal spray vaccine (LAIV) if the child has no contraindications or precautions to this vaccine. Recent studies indicate that the nasal spray flu vaccine may provide better protection for children, and these studies showed that the nasal spray flu vaccine prevented approximately 50% more cases than the flu shot in children. However, if the nasal spray vaccine is not available, children 2 -8 years old should get the flu shot. Do not delay vaccinating waiting for the nasal spray flu vaccine.
Flu activity in the US. (Courtesy http://www.cdc.gov)
How effective is the 2014-2105 influenza vaccine?
On December 3rd, the CDC released a report stating:
Influenza viral characterization data indicates that 48% of the influenza A (H3N2) viruses collected and analyzed in the United States from October 1 through November 22, 2014 were antigenically “like” the 2014-2015 influenza A (H3N2) vaccine component, but that 52% were antigenically different (drifted) from the H3N2 vaccine virus. In past seasons during which predominant circulating influenza viruses have been antigenically drifted, decreased vaccine effectiveness has been observed. However, vaccination has been found to provide some protection against drifted viruses.
Specifically, on November 22nd, of the 1,228 influenza-positive tests reported to CDC, 1,123 (91.4%) were influenza A viruses and 105 (8.6%) were influenza B viruses. Of the 85 influenza A (H3N2) viruses collected by US laboratories and antigenically studied at CDC since October 1, 2014, 44 (52%) are significantly different from A/Texas/50/2012, the US H3N2 vaccine virus. These findings raise concerns that the 2014-2014 flu season may be more severe than the past few years. The CDC still strongly recommends people continue getting the flu vaccine since it will still provide a level of protection.
CDC Director Dr. Tom Frieden said, “One thing to understand about flu, always, is that it is unpredictable. Every season is different, with different flu viruses spreading and causing illness.”
Due to concerns about decreased effectiveness of this year’s flu vaccine, the CDC and public health officials are recommending early & enhanced use of anti-virals within 48 hours for patients with influenza-like illnesses, especially for higher risk patients that include:
- is hospitalized
- has severe, complicated, or progressive illness
- is at higher risk for influenza complications. This list includes:
- children aged younger than 2 years
- adults aged 65 years and older
- persons with chronic pulmonary (including asthma), cardiovascular (except hypertension alone), renal, hepatic, hematological (including sickle cell disease), and metabolic disorders (including diabetes mellitus), or neurologic and neurodevelopment conditions (including disorders of the brain, spinal cord, peripheral nerve, and muscle such as cerebral palsy, epilepsy [seizure disorders], stroke, intellectual disability [mental retardation], moderate to severe developmental delay, muscular dystrophy, or spinal cord injury)
- persons with immunosuppression, including that caused by medications or by HIV infection
- women who are pregnant or postpartum (within 2 weeks after delivery)
- persons aged younger than 19 years who are receiving long-term aspirin therapy
- American Indians/Alaska Natives
- persons who are morbidly obese (i.e., body-mass index is equal to or greater than 40)
- residents of nursing homes and other chronic-care facilities
Choice of anti-virals
Oseltamivir (Tamiflu) is approved to treat patients 2 weeks and older and to prevent influenza in people 1 year and older. Zanamivir (Relenza) is approved to treat patients 7 years and older and to prevent influenza in persons 5 years and older. Because high levels of resistance to adamantane antiviral medications continue to be observed among circulating influenza A viruses, adamantanes (rimantadine and amantadine) are not recommended for treatment or prevention of influenza.
Prevention, Prevention, Prevention…
The CDC is urging all people to “Take 3 Actions” to prevent the spread of flu this year:
- Take the time to get the flu vaccine
- Take everyday steps to stop the spread of germs
- Cover nose & mouth when sneezing
- Avoid sick individuals
- While sick, limit contact with others and stay home if you have a fever
- Take flu anti0viral medicine if prescribed to you
It will take a collective public health effort to limit the deadly impact of influenza this year.
Report written by Bobby Kapur, MD, MPH.