Most people recover from seasonal influenza infections within a week. However, influenza can cause serious complications in some high risk groups.
In 2015/16, the Scientific Committee on Vaccine Preventable Diseases recommends the following target groups for seasonal influenza vaccination in Hong Kong:
- Pregnant women;
- Elderly persons living in residential care homes;
- Long-stay residents of institutions for the disabled;
- Persons aged 50 years or above;
- Persons with chronic medical problems* ;
- Health care workers;
- Children between the age of 6 months and less than 6 years;
- Poultry workers; and
- Pig farmers and pig-slaughtering industry personnel.
*People with chronic medical problems mainly refer to those who have chronic cardiovascular (except hypertension without complication), lung, metabolic or kidney diseases, obesity# (BMI 30 or above), who are immunocompromised^, children and adolescents (aged 6 months to 18 years) on long-term aspirin therapy, and those with chronic neurological condition that can compromise respiratory function or the handling of respiratory secretions or that can increase the risk for aspiration or those who lack the ability to take care for themselves.
# Obesity is considered as an independent risk factor for influenza complication and thus people with BMI 30 or above are included for seasonal influenza vaccination.
^People who are immunocompromised refer to those with a weakened immune system due to disease (such as HIV/AIDS) or treatment (such as cancer treatment).
Given influenza vaccines are safe and effective and that serious influenza infection can occur even in healthy individuals, influenza vaccination is suitable for personal protection against clinical influenza for all persons except those with known contraindications. Members of the public can consult their family doctors to receive influenza vaccination for personal protection.
In Hong Kong, influenza is usually more common in periods from January to March and from July to August. It takes about two weeks after vaccination for antibodies to develop in the body. Get vaccinated early to ensure protection.