Flu or influenza is an acute respiratory tract infection caused by influenza viruses- primarily type A and B. The disease is characterized by abrupt onset of respiratory symptoms often associated with systemic signs and symptoms like fever, headache, generalized body ache and weakness. Outbreaks of influenza generally occur during winter and it has a worldwide distribution.
WHY GET VACCINATED AND WHO NEED IT?
There are enough reasons why to go for the influenza vaccines. They range from medical, social to economic implications. Not only the person has to suffer but also the country loses a burgeoning amount in terms of days of absence from work and decreased productivity.
1. Flu really strikes very hard on a person. The disease causes great deal of suffering to leave a person exhausted and keep him even bed-ridden for a week or two.
2. If you have children or elderly persons above the age of 65 years in your family, you should go for the vaccine as these people are at greater risk of developing complications from influenza. Vaccination reduces risk of infection to a great extent.
3. People with chronic pulmonary or cardiovascular diseases like asthma, COPD, chronic bronchitis and heart failure are at increased risk of worsening their underlying disease condition and death due to influenza.
4. Vaccination also saves time as well as money as it protects from illness and the cost of vaccination is much less than the cost of treatment of flu. If you are a person who cannot afford to lose 10-14 days to the illness, better get vaccinated. Children and adults benefit from decreased absenteeism from school and workplace.
5. Threatened pandemic by a new virus is another situation where vaccination becomes mandatory as during pandemics the complication rate and death rate increase.
6. Children and adolescents between the age group of six months to 18 years on long-term aspirin therapy, as they are at an increased risk of developing Reye’s syndrome (a form of hepatic encephalopathy) after influenza. Hence need to be immunized.
7. Pregnant women during the influenza season can have chances of increased abortion and thus advised to get immunized.
8. People who need regular medical check up or hospitalization for chronic metabolic diseases, immunodeficiency diseases or other debilitating disease should get vaccinated because of high risk of complications and mortality in these groups of patients.
9. People who live with or come in close contact with influenza patients like the family members of these patients and those who care for them are at high risk of acquiring the disease and should get themselves vaccinated.
10. Lastly, health care workers and laboratory workers who stand at a greater risk of contracting the disease due to their proximity to the virus should get vaccinated. This reduces the potential of transmitting the infection to others.
11. To prevent loss of manpower in critical public services like police, fire protection, transport and of course medical care to flu and prevent disruption of these essential services, personnel employed in these services should be vaccinated regularly.
Vaccines are used primarily as a health measure for prevention of influenza. The vaccine for influenza are of two types-inactivated and live attenuated, with the former being used on a large scale throughout the world.
Inactivated vaccines are prepared from influenza A and B virus strains that circulated during previous influenza season. However, few individuals experience low grade fever and mild systemic symptoms. Development of local redness and tenderness at the vaccination site normally occurs. Efficacy is 70-80%. People allergic to egg proteins should not go for the vaccines so as infants below the age of 6 months.
The live attenuated vaccine is given as intranasal instillation and it is prepared from influenza type A and B viruses which are prevalent in the current season. This vaccine provides better protection and recommended for age group 5-49 years and the efficacy of the vaccine in children has been estimated to be 90%. This vaccine cannot be given to pregnant women for the fear of miscarriages and possible deformities in the child. Immune-compromised states like those suffering from HIV-AIDS are also a contraindication for vaccination with live-attenuated vaccine.
Fewer side effects associated with the newer sub-unit vaccines make them an attractive option for prevention of the illness.
IDEAL TIME OF VACCINATION-
Inactivated vaccines can be administered safely to immunocompromised patients including HIV infected persons whereas live vaccines are a contraindication for them. To prevent epidemics the vaccine must be administered at least two weeks prior to onset of an epidemic or 2-3 months before an epidemic of influenza is expected. It can be then given annually to maintain immunity against currently prevalent strain. Every year recommendations are made by the WHO as to what strains should be included in the vaccine.
BENEFITS OF VACCINATION-
Routine vaccination is recommended only in certain groups who are at high risk of developing complications as mentioned above. But, it has been well established that the benefits of vaccination in preventing infection and associated complications as well as reducing morbidity and mortality in the population outweighs the cost and risks associated with vaccination.