Health Guide and Education Online

H1n1 is a strain of the influenza virus that historically only affected pigs. However, in spring 2009, it emerged in people in north america. This is a different strain of influenza and because humans have miniscule to no natural immunity to this virus, it can cause serious and widespread illness

A flu vaccine is currently the best way to protect against influenza sickness. There are two kinds of H1N1 vaccines being produced:

1. A H1N1 “flu shot” — an inactivated vaccine (containing killed virus) that is given with a needle, usually in the arm. The indications for who can get the H1N1 flu shot are the same as for seasonal flu shots. The flu shot is approved for use in people 6 months of age and older, including healthy people, people with chronic medical conditions and pregnant women. The same manufacturers who produce seasonal flu shots are producing H1N1 flu shots for use in the United States this season. The H1N1 flu shot is being made in the same way that the seasonal flu shot is produced.
2. The H1N1 nasal spray flu vaccine — a vaccine made with live, weakened viruses that do not cause the flu (sometimes called LAIV for “live attenuated influenza vaccine”). The indications for who can get the H1N1 nasal spray vaccine are the same as for seasonal nasal spray vaccine. LAIV is approved for use in healthy people 2 years to 49 years of age who are not pregnant. The nasal spray vaccine for use in the United States is being made by MedImmune, the same company that makes the seasonal nasal spray vaccine called “FluMist®.” The H1N1 nasal spray vaccine is being made in the same way as the seasonal nasal spray vaccine.

About 2 weeks after vaccination, antibodies that provide protection against 2009 H1N1 influenza virus infection will develop in the body.

H1N1 Vaccine Information

The U.S. Food and Drug Administration (FDA) has approved the use of one dose of 2009 H1N1 flu vaccine for persons 10 years of age and older. This is slightly different from CDC’s recommendations for seasonal influenza vaccination which states that children younger than 9 who are being vaccinated against influenza for the first time need to receive two doses. Infants younger than 6 months of age are too young to get the 2009 H1N1 and seasonal flu vaccines.

Vaccination against H1N1 should begin as soon as vaccine is available and continue throughout the influenza season, into December, January, and beyond. This is because the timing and duration of flu activity can vary. Flu seasons can last as late as April or May. By early October 2009, extensive H1N1 flu activity was being reported in the United States.

It’s possible that there may be waves of H1N1 activity during the 2009-2010 flu season that hit communities more than once over the course of the season. While H1N1 viruses are likely to be the most common cause of influenza this season, CDC still expects that seasonal influenza viruses will circulate and continues to recommend that people get a seasonal flu vaccine to protect against seasonal flu viruses

Most people who get the flu will have mild illness, will not need medical care or antiviral drugs, and will recover in less than two weeks.  Some people, however, are more likely to get flu complications that result in being hospitalized and occasionally result in death.

Pneumonia, bronchitis, sinus infections and ear infections are examples of flu-related complications. The flu can also make chronic health problems worse. For example, people with asthma may experience asthma attacks while they have the flu, and people with chronic congestive heart failure may have worsening of this condition that is triggered by the flu.

The list below includes the groups of people more likely to get flu-related complications if they get sick from influenza.

People at High Risk for Developing Flu-Related Complications

• Children younger than 5, but especially children younger than 2 years old
• Adults 65 years of age and older
• Pregnant women

People who have medical conditions including:

• Asthma
• Neurological and neurodevelopmental 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].
• Chronic  lung disease   (such as chronic obstructive pulmonary disease  [COPD] and cystic fibrosis)
• Heart disease (such as congenital heart disease, congestive heart failure and coronary artery disease)
• Blood disorders (such as sickle cell disease)
• Endocrine disorders (such as diabetes mellitus)
• Kidney disorders
• Liver disorders
• Metabolic disorders (such as inherited metabolic disorders and mitochondrial disorders)
• Weakened immune system due to disease or medication (such as people with HIV or AIDS, or cancer, or those on chronic steroids)
• People younger than 19 years of age who are receiving long-term aspirin therapy

It is also important to keep in mind the warning signs of a more serious illness requiring immediate medical attention. In children, these symptoms include fast breathing, trouble breathing, bluish skin color, not drinking enough fluids, not waking up, not interacting, being so irritable that the child does not want to be held, or if flu-like symptoms improve, but then return with a worse cough, fever or fever with a rash.

In adults, warning signs include difficulty breathing or shortness of breath, pain or pressure in the chest or abdomen, sudden dizziness, confusion, or severe or persistent vomiting.