While current reports of the H1N1 nasal spray vaccine side effects are mild, there are certain groups of people who should not use the inhaled swine flu (H1N1) vaccine, due to the live virus. The intranasal form of vaccine, for inhalation through the nose, is the only form of the vaccine that contains a living form of the swine flu virus. The H1N1 nasal spray vaccine should not be given within a month of the seasonal flu nasal spray vaccine, to prevent lowered immunity for both strains.
Live Virus Attenuation Process
The living H1N1 virus in the nasal spray vaccine has been weakened in a laboratory in a process called attenuation. The virus is allowed to duplicate repeatedly in different environments in order to reduce its ability to reproduce or thrive in a human's body. An attenuated virus is strong enough to initiate a robust immune response from an immune system, but too weak to cause infection in a typical person's system. The attenuated living virus found in the H1N1 nasal spray vaccine is designed to be unable to exist outside the nasal passages.
Age Range for Live Nasal Spray Vaccine
The H1N1 live nasal spray vaccine is not approved for children under the age of two years. In addition, adults over the age of 50 years should not receive the H1N1 nasal spray vaccine. These individuals are encouraged to receive an inactivated vaccine by injection, rather than the live intranasal vaccine.
Avoiding the H1N1 Intranasal Vaccine
Other groups who should avoid the H1N1 intranasal vaccine are pregnant women, anyone who is at high risk for flu complications, and children under the age of five years who have any history of wheezing or asthma, even a single episode. In addition, children and teenagers who are undergoing aspirin therapy should not use the intranasal flu vaccine, in order to prevent Reyes Syndrome. Anyone who has had Guillain-Barré syndrome, a rare nerve disease, should also avoid this vaccine. Egg allergies or concerns about pork products are additional reasons for avoidance of the live H1N1 vaccination.
Groups at High Risk for H1N1 Complications
Certain ongoing health conditions increase the chance of complications from any influenza infection, whether it is swine flu or seasonal flu. Chronic conditions such as these tend to weaken the body, lowering the defenses, and making the individual more susceptible to infection and side effects:
- heart disease
- lung disease
- asthma
- diabetes
- kidney failure
- conditions that result in compromised immune systems
Side Effects of H1N1 Intranasal Vaccine
In healthy individuals who receive the H1N1 nasal spray vaccine as directed, side effects are currently being reported as mild. These side effects may include:
- fever
- headache
- muscle aches
- runny nose
- vomiting
- wheezing
- sore throat
- cough
Infection from Contact with Live Virus
According to the CDC, it is extremely rare for an individual who has been vaccinated with the live virus to transmit that virus to another individual. In fact, they estimate the contagion risk to be under 3%. In addition, the weakened state of the virus during vaccination would prevent a full flu infection even if the virus was transmitted.
References:
U.S. Centers for Disease Control and Prevention
U.S. Food and Drug Administration
Victoria Nicks - Victoria Nicks has a Master's Degree in IT, and extensive hands-on experience with various types of hardware and software.
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