By Sheila Kun RN, BSN, MS, CPN, FCCP
This is our last discussion on the subject of influenza vaccination. As noted before, although the U.S. has one of the highest vaccination rates in the world, only 45 percent of adults and 63 percent of children get flu shots each year. For some people, the question of its efficacy remains. We need to be aware that the vaccine’s effectiveness varies dramatically depending on how well it matches the viruses circulating in a given season. In good years, the vaccine protects 50 to 70 percent of the people receiving it. But some strains are more difficult to create vaccines for, such as the H3N2 type, which raged during the severe 2017 flu seasons.
Another barrier is that scientists are still not able to create a universal flu vaccine that would provide lasting protection against all forms of the virus. The future is to train the immune system by targeting the stem of a protein on the virus, which varies little from strain to strain. However, our bodies don’t generate many antibodies to target this part of the virus, instead focusing on the frequently changing head. Because of a process called “imprinting” – in which the immune system learns how to fight viruses based on the first encounter – it is difficult to teach the body new habits.
Lastly let us consider the following risk factors:
A history of Guillain-Barré Syndrome (GBS) ( a condition with neuromuscular weakness) within 6 weeks of a previous dose of any type of influenza vaccine is considered a precaution to vaccination and should not be vaccinated.
Persons with a History of Egg Allergy
As is the case for all vaccines, influenza vaccines contain various different components that might cause allergic and anaphylactic reactions. Not all such reactions are related to egg proteins; however, the possibility of reactions to influenza vaccines in egg-allergic persons might be of concern to these persons and vaccine providers. Most influenza vaccines, are prepared by propagation of virus in embryonated eggs and might contain trace amounts of egg proteins, such as ovalbumin.
Severe allergic reactions to vaccines, although rare, can occur at any time, even in the absence of a history of previous allergic reaction. Therefore, all vaccine providers should be familiar with the office emergency plan and be certified in cardiopulmonary resuscitation .
No post-vaccination observation period is recommended. However, it is recommended that vaccine providers consider observing patients (seated or supine) for 15 minutes after administration of any vaccine to decrease the risk for injury should syncope (fainting) occur.
Vaccination Issues for Travelers
Travelers who want to reduce the risk for influenza infection should consider influenza vaccination, preferably at least 2 weeks before departure. In particular, persons who live in the United States and are at higher risk for complications of influenza and who were not vaccinated with influenza vaccine during the previous Northern Hemisphere fall or winter should consider receiving influenza vaccine before departure if they plan to travel to the tropics, with organized tourist groups or on cruise ships, or to the Southern Hemisphere during the Southern Hemisphere influenza season (April–September).
This concludes our discussion on influenza vaccination. I hope you have enough information to make an educated decision during this flu season.
The homework from the Care Ministry this week: go ahead and get your flu shot, if you haven’t done so.
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