About Vaccination - Influenza

When I take Willow to the Pediatrician and she gets any kind of shots, the doctor gives us a pamphlet with information on the shots (Likely from the CDC). So, since everyone is all up in arms about the links between vaccinations and things like autism, I thought I'd take an in-depth look at the vaccinations. Next in line is the Influenza (Flu) Vaccination.

The United States' Centers for Disease Control and Prevention (CDC) Vaccinations and Immunizations section has a recommended immunization schedule that you can download. They also have a lot of great information for each and every vaccination so this is where I will start in my search for information. Here is their pamphlet on the Influenza Vaccination.

The Influenza Vaccination is given in one dose yearly. The first dose can be administered when your child is 6 months of age. This vaccination is may be given at the same time as other vaccinations.

First, what exactly is Influenza?

Influenza is a highly contagious respiratory illness caused by a virus. Three specific influenza virus strains are responsible for illness in humans. Influenza type A and type B viruses cause moderate to severe illness in humans, and type C may cause no symptoms or only a mild respiratory illness. Influenza types A and B viruses circulate almost every winter. Each influenza type has a different nuclear make up. Type A influenza generally causes moderate to severe illness and infects both humans and animals such as pigs and birds. Type B only affects humans, primarily affects children and generally causes milder illness than influenza A. Influenza season usually begins in October and continues thru the following May, but tends to peak between November and March. Influenza can occur throughout the year particularly in tropical areas, but in temperate regions like the United States, influenza tends to occur in the fall and winter. In the Southern Hemisphere, influenza generally peaks from April through September. Travelers also can get the flu during the summer, especially when traveling to areas of the world where the flu is active.

How about a brief History of Influenza? The symptoms of human influenza were clearly described by Hippocrates roughly 2,400 years ago. Since then, the virus has caused numerous pandemics. Historical data on influenza are difficult to interpret, because the symptoms can be similar to those of other diseases, such as diphtheria, pneumonic plague, typhoid fever, dengue, or typhus. The first convincing record of an influenza pandemic was of an outbreak in 1580, which began in Asia and spread to Europe via Africa. In Rome, over 8,000 people were killed, and several Spanish cities were almost wiped out. Pandemics continued sporadically throughout the 17th and 18th centuries, with the pandemic of 1830–1833 being particularly widespread; it infected approximately a quarter of the people exposed.

The most famous and lethal outbreak was the so-called Spanish flu pandemic (type A influenza, H1N1 subtype), which lasted from 1918 to 1919. Older estimates say it killed 40–50 million people, while current estimates say 50 million to 100 million people worldwide were killed. This pandemic has been described as "the greatest medical holocaust in history" and may have killed as many people as the Black Death.

The Spanish flu pandemic was truly global, spreading even to the Arctic and remote Pacific islands. The unusually severe disease killed between 2 and 20% of those infected, as opposed to the more usual flu epidemic mortality rate of 0.1%. As many as 25 million may have been killed in the first 25 weeks; in contrast, HIV/AIDS has killed 25 million in its first 25 years. Later flu pandemics were not so devastating. They included the 1957 Asian Flu (type A, H2N2 strain) and the 1968 Hong Kong Flu (type A, H3N2 strain), but even these smaller outbreaks killed millions of people. In later pandemics antibiotics were available to control secondary infections and this may have helped reduce mortality compared to the Spanish Flu of 1918

Now that we know about Influenza, how was the vaccination Developed?

In the world wide Spanish flu pandemic of 1918, "Physicians tried everything they knew, everything they had ever heard of, from the ancient art of bleeding patients, to administering oxygen, to developing new vaccines and sera (chiefly against what we now call Hemophilus influenzae—a name derived from the fact that it was originally considered the etiological agent—and several types of pneumococci). Only one therapeutic measure, transfusing blood from recovered patients to new victims, showed any hint of success."

In 1931, viral growth in embryonated hens' eggs was discovered, and in the 1940s, the US military developed the first approved inactivated vaccines for influenza, which were used in the Second World War. Greater advances were made in vaccinology and immunology, and vaccines became safer and mass-produced. Today, thanks to the advances of molecular technology, we are on the verge of making influenza vaccines through the genetic manipulation of influenza genes.

For a little more on how the vaccine is produced, you can see an earlier post I did on the Flu, which has a pictured timeline.

Symptoms of Influenza include the abrupt onset of fever often associated with headache, extreme tiredness, dry cough, sore throat, nasal congestion, and body aches are characteristic of influenza illness. Occasionally, intestinal symptoms such as nausea, vomiting, diarrhea, and abdominal pain may be present (especially in children), but should not be confused with the “stomach flu.”

So, now that we know about Influenza and the development of the vaccination, let's take a look at the CDC information on the vaccination.

First of all, there are two types of Influenza Vaccine.

1. Inactivated (killed) vaccine, or the “flu shot” is given by injection into the muscle.


2. Live, attenuated (weakened) influenza vaccine is sprayed into the nostrils. This vaccine is described in a separate Vaccine Information Statement.

Some inactivated influenza vaccine contains a preservative called thimerosal. Some people have suggested that thimerosal may be related to developmental problems in children. In 2004 the Institute of Medicine reviewed many studies looking into this theory and concluded that there is no evidence of such a relationship. Thimerosal-free influenza vaccine is available.

Risks of Influenza vaccination - Serious problems from influenza vaccine are very rare. The viruses in inactivated influenza vaccine have been killed, so you cannot get influenza from the vaccine.

Mild problems:

• soreness, redness, or swelling where the shot was given


• fever


• aches

If these problems occur, they usually begin soon after the shot and last 1-2 days.

Severe problems:

• Life-threatening allergic reactions from vaccines are very rare. If they do occur, it is usually within a few minutes to a few hours after the shot.


• In 1976, a type of influenza (swine flu) vaccine was associated with Guillain-Barré Syndrome (GBS). Since then, flu vaccines have not been clearly linked to GBS. However, if there is a risk of GBS from current flu vaccines, it would be no more than 1 or 2 cases per million people vaccinated. This is much lower than the risk of severe influenza, which can be prevented by vaccination.

Some people should talk to their doctor before getting the Influenza Vaccination.

• Tell your doctor if you have any severe (life-threatening) allergies. Allergic reactions to influenza vaccine are rare.
  


• Influenza vaccine virus is grown in eggs. People with a severe egg allergy should not get the vaccine.


• A severe allergy to any vaccine component is also a reason to not get the vaccine.


• If you have had a severe reaction after a previous dose of influenza vaccine, tell your doctor.
  


• Tell your doctor if you ever had Guillain-Barré Syndrome (a severe paralytic illness, also called GBS). You may be able to get the vaccine, but your doctor should help you make the decision.


• People who are moderately or severely ill should usually wait until they recover before getting flu vaccine. If you are ill, talk to your doctor or nurse about whether to reschedule the vaccination. People with a mild illness can usually get the vaccine.

I found an awesome website that lists the package inserts and ingredients for all available vaccinations (e.g. provided by MERK or GlaxoSmithKline). It's called the World Association for Vaccine Education. You can find their page on the Influenza Vaccine here.


More Information:

• Guide to Contraindications to Vaccination (a Contraindication is a condition or factor that increases the risks involved in using a particular drug, carrying out a medical procedure, or engaging in a particular activity.)


• Parents Guide to Childhood Immunization


• Division of Environmental Health and Communicable Disease Prevention pamphlet on Influenza


• VaccineInformation.org - The Immunization Action Coalition works to increase immunization rates and prevent disease by creating and distributing educational materials for health professionals and the public that enhance the delivery of safe and effective immunization services. The Coalition also facilitates communication about the safety, efficacy, and use of vaccines within the broad immunization community of patients, parents, health care organizations, and government health agencies.


• Facts for Parents About Vaccine Safety from the AAP

And since there are those people that are concerned about links of vaccinations to neurological disorders and the like I thought I'd include some of their links as well:

Generation Rescue is an international movement of scientists, physicians and parent-volunteers researching the causes and treatments for autism and mentoring thousands of families in recovering their children from autism.

The Thinktwice Global Vaccine Institute was established in 1996 to provide parents and other concerned people with educational resources enabling them to make more informed vaccine decisions. Thinktwice encourages an uncensored exchange of vaccine information, and supports every family's right to accept or reject vaccines. Thinktwice's Influenza (Flu) page.


I asked my pediatrician if she had a lot of parents who were choosing to NOT vaccinate their children. She said she could count on one hand the total number and that she, of course, recommends AGAINST not vaccinating your children.

Previously:
Hepatitis B Vaccination Information
Rotavirus Vaccination Information
Diphtheria Vaccination Information
Tetanus Vaccination Information
Pertussis (Whooping Cough) Vaccination
Haemophilus influenzae type b (Hib) Vaccination Information
Pneumococcal Conjugate Vaccination Information
Polio Vaccination Information

Next week: Measles