Influenza is a contagious respiratory disease that occasionally causes widespread epidemics, especially in urban societies where people work in buildings, use shared ventilation systems or rely on crowded public transportation such as trains and planes. The rapid international travel has led to easier and faster disease outbreaks. Vaccination for people at risk of severe complications after contracting influenza is highly necessary.
Influenza is a disease caused by the influenza virus (Influenza Virus)
The disease affects the respiratory system and is more severe than other respiratory viruses, particularly in at-risk groups that could result in death.
At-risk groups include
- Elderly people
- People with chronic diseases such as lung diseases, heart diseases, diabetes, pregnant women
- People with weak immune systems
Symptoms of Influenza
- Fever
- Headache
- Muscle soreness
- Tiredness
- Dry cough
- Sore throat
- Runny nose
- In children, there may be symptoms of nausea, vomiting, diarrhea
The disease can occur throughout the year, but outbreaks are more common in the rainy season. Influenza is transmitted through the mucus of patients by coughing or sneezing into the mouth and nose of people nearby. Less commonly, it can also be transmitted by touching objects contaminated with the patient’s mucus and then touching the mouth or nose.
Complications
Elderly people and those with chronic diseases are at risk of complications such as
- Bacterial pneumonia
- Dehydration
- Worsening of existing chronic conditions such as heart failure, asthma, diabetes, which can lead to death
Prevention
- Vaccination is the best prevention
- Avoid contact with sick people and their mucus
- Wash hands frequently
- Avoid touching your own mouth, eyes, and nose after contacting sick people
- If you suspect influenza symptoms, stay away from others and cover your mouth and nose when coughing or sneezing
Who should get vaccinated
- Elderly people
- People with chronic conditions such as chronic lung diseases, asthma, diabetes, kidney diseases, heart diseases, liver diseases, AIDS
- Family members of individuals with such chronic conditions
- Pregnant women after the first 3 months
- People who want to reduce the risk of infection
Normally, the vaccine should be administered before the outbreak season. In Thailand, it’s recommended to get vaccinated between January and June every year. Immunity develops about 2 weeks after vaccination. It’s necessary to vaccinate annually because the influenza virus changes strains that are prevalent and the vaccine provides immunity to specific strains for only about 1 year. The prevalence of influenza can change quickly, and the vaccine produced each year targets the strain that is currently prevalent. Thus, vaccination is needed every year.
Effectiveness of the Vaccine
The vaccine is about 70 – 90 % effective in preventing the disease, but in elderly people, the response to the vaccine may be less due to lower normal immunity. However, it still benefits in reducing complications, the likelihood of hospitalization, and death.
