Every year, when the Centers for Disease Control in Atlanta sound the ‘Flu alarm’ and suggest to vaccinate children and adults against the three new annual strains of influenza, families are gathered at the dinner table to decide if they need to vaccinate or not. Pediatricians are recommending to vaccinate, but not all of them sound as confident as when they speak about measles or rubella. But what about the 10% or so of the population of children with asthma? Are they in the "must have" group to be vaccinated?
Asthma, a small airways disease, includes wheezing (a hissing sound while breathing), chest tightness, shortness of breath and coughing. During an asthma episode, or an asthma attack, symptoms are worse than usual, resulting at times in an ER visit.
Viral infections are a known culprit for asthma attacks and for some parents the tradition of winter includes a monthly or even weekly asthma attack, every time the child (or their sibling) brings home a new virus from daycare or school. Health organizations encourage administration of the annual flu shots to asthmatic children in order to protect them against seasonal influenza viruses. So, does the flu shot prevents asthma attacks?
Injection or Nasal Spray
Currently there are two types of flu vaccinations: injection (“flu shots”) and nasal spray vaccines. In the 2014 flu season the US was ready with enough of those vaccines for the whole population. The injection is an inactivated vaccine, containing killed influenza virus. Those killed flu particles are injected into muscles or skin and stimulates the immune system to produce a response (antibodies) to the influenza virus. The nasal spray flu vaccine is directed against the same strains of virus as the flu shot but differs in that it contains weakened live influenza viruses (not killed) . Scientists call this form of vaccine - an attenuated vaccine, that is not causing severe flu symptoms. Flu vaccines are seasonal and are developed each year because the influenza virus mutates and changes its structure slightly. Western countries learn from the Far East about strains of influenza that will ‘attack’ in the winter and based on these, a vaccine is developed.
Does the 'Flu Shot' reduce the number of asthma attacks?
While infection with influenza can lead to diverse respiratory complications, the exact role influenza plays in directly inducing asthma attacks is not well established. A large study which was carried out in the United States showed that vaccinating reduces the risk of asthma exacerbation by 22% to 41%. Another body of research showed that asthmatic children vaccinated against influenza needed less oral steroids (like prednisone) during the winter months compared to asthmatic children who were not vaccinated. While these results are encouraging there is still a need for larger scale studies in order to establish the impact of the flu vaccine on the number and severity of asthma attacks.
Which Vaccine to Choose for My Asthmatic Child?
Flu shots are safe at any age. Side effects include soreness at the site of the injection, muscle aching, fever, and feeling unwell. The safety of live, attenuated (nasal spray) vaccine was investigated in several large scale studies. One research study which included children 6 months to 3 years old found association between flu vaccination with nasal spray and higher hospital admission rates of children younger than 12 months of age. The researchers also showed that asthmatic children tended to wheeze more in the weeks after the nasal spray vaccination. Some other research showed no increased risk of wheezing after the nasal spray vaccine, so the jury is still out on the risks of the nasal spray for infants.
MedSchoolForParents.com recommendation is that until more data is available, children younger than 2 years old and children with a history of recurrent wheezing or asthma should NOT receive the nasal spray vaccination but rather be vaccinated using the injection (flu shots).