In the past years, there were four separate influenza pandemics that have killed millions globally and an equal number have perished due to seasonal influenza. The two flu viruses, namely influenza A and B are responsible for almost all cases of flu among humans.
Influenza A is responsible for all the global pandemics and most cases of regional epidemics. As for influenza B, it goes along with influenza A and causes occasional epidemics. The vaccination against these two viruses is relatively safe and effective and capable of relieving a large measure of health issues linked with the flu. You can take on a course on first aid today so that you are ready to handle a case of flu especially if a family member acquires one.
What are the types of flu vaccines?
The flu vaccines were introduced back in the 1940s. It is important to note that the only type of vaccine available until 2003 was comprised of killed or deactivated viruses and was given via injection into a muscle. After a few years, a vaccine that contained live, weakened viruses was developed and administered as a nasal spray.
All of the flu vaccines are manufactured with egg-based technologies until 2013 in which the vaccine was produced without using eggs or whole viruses.
Safety of using inactivated flu vaccines
The flu vaccines have gained an excellent safety record during years of use. Back in 1976 during the swine flu epidemic, it is believed that the inactive vaccine was linked to an increased incidence of Guillain-Barre syndrome which is a potentially fatal immune disorder that damages the nervous system. On the other hand, no other seasonal flu vaccine has been linked with Guillain-Barre syndrome and the number of cases who develop the syndrome is generally the same in both unvaccinated and vaccinated individuals.
The usual side effects of inactivated flu vaccines include soreness and reddening at the site where the vaccine was administered. Some of those who were given the vaccine complain of fever, chills and body aches. Since the inactivated vaccines do not contain live viruses, they could not cause flu.
Safety when using live or weakened flu vaccines
The usual adverse effects of the vaccines that contain live or weakened viruses include stuffy nose, headache, muscle aches and fever. In some cases, wheezing can occur in young children. Additionally, those who have medical issues that makes them prone to influenza-related complications such as elderly, those who have diabetes, pregnant women or those who have weakened immune systems should not be given the vaccine.
Effectiveness
The flu viruses continue to alter their genetic structures to escape the immune system of those that they infect. Every year, researchers should develop new vaccines to match the viruses during the flu season. A flu vaccine is 70-90% effective in preventing flu if it is suitable for the current strains.
In the years to come, if the vaccines are not well-matched for the existing strains, the individual is more likely to acquire the flu but it will be a mild case if he/she is vaccinated. Take note that flu vaccines are less effective among the elderly due to their weakened immune response.