All about the flu vaccine and why you should get one
Influenza is caused by the influenza virus which is a very dangerous pathogen and causes potentially serious disease which leads to hospitalization and death in extreme cases. Influenza outbreak is a burden on the economy and public health.
Multiple factors are responsible for the spread of influenza, including household structure, virus and host interaction, individual behavior, and viral persistence in the environment. The association of temperature or humidity with influenza differs from region to region, countries having dry-cold and rainy-humid climates are associated with influenza outbreaks.
The relationship between humidity and influenza transmission is unclear, it is thought to modulate influenza activity during seasonal change.
Every year millions of people get infected by influenza and thousands of people die. The transmission rate of the influenza virus is very high and the most effective way to control this virus is by getting the annual flu shot the flu shot has many benefits
· Reducing the risk of flu illness
· Reducing the risk of hospitalization
· Reducing the risk of death in children
There are many different flu vaccines they are licensed and recommended for use in US. There are trivalent (three virus)and tetravalent (four virus), trivalent vaccine protects against two influenza A viruses and one influenza B virus while tetravalent vaccine provides protection against two influenza A viruses and two influenza B viruses.
Different methods are used to make these vaccines these include inactivated influenza vaccine, recombinant influenza vaccine or live attenuated vaccine.
Why do we need a flu vaccine every year?
There are so many vaccines that are administered twice or thrice in our whole life span providing lifelong immunity but influenza vaccine needs to be administered annually as it provides protection against the viruses that research indicates will be most pathogenic that year.
Influenza virus undergoes mutation by “genetic drift” There are two important surface proteins influenza virus that include HA (hemagglutinin) and NA (neuraminidase). These are also known as antigens, our immune system recognize these surface proteins and immune response is generated against them to produce antibodies. Nasal vaccine targets both HA and NA, While most of the other vaccines target generally HA.
Adaptive mutations occur abruptly and animal origin influenza virus mutates and infects human population, such a mutation occurred in 2009 influenza outbreak, there have been four influenza pandemics in last 100 years.
When should I get vaccinated?
It takes about 2 weeks to develop antibodies after vaccination against influenza virus, so one should get vaccinated early in the fall before the beginning of flu season. Children who need two doses must start vaccination earlier as two doses need to be one month apart.
Vaccine Effectiveness
Flu shot provides 40 to 60% protection, because of many different factors including rapid mutation rate and the absence of a certain mutated strain in the vaccine. Researchers are working hard to make an effective and universal vaccine that would provide long-lasting immunity against multiple types of flu.
Who should be vaccinated?
· Elderly people (aged 65 years and older)
· Health care workers and doctors
· Obese
· infants (6 months and 2 years)
· Patients with chronic diseases such as asthma, diabetes, kidney or cardiac disease and those who are on immunosuppressive drugs.
While infants younger than 6 months, pregnant women, people with serious allergies, and those people who have had severe reactions to flu vaccines in the past should not be vaccinated.
