Influenza is a serious infection with unexpected, severe consequences.
Flu or influenza is a highly contagious disease. Anyone can catch and spread it within their community.
Everyone is at risk of influenza, as the disease spreads easily through coughing, sneezing or talking.
There are four main types of flu viruses with multiple sub-types that can infect people. Each season it’s difficult to predict exactly which subtypes of the viruses will dominate, their severity, and the full impact on public health.
Influenza can affect anyone, young or old and seriously disrupt lives, economies and societies. It accounts for a significant part of the annual economic burden of vaccine-preventable diseases across Asia.
In healthy people of any age, the impact of influenza is unpredictable and can lead to serious consequences such as pneumonia, heart attacks, and stroke.
Each year, 3 to 5 million cases of severe flu are reported worldwide.
In vulnerable populations such as people living with diabetes, asthma, chronic heart or lung diseases, influenza causes higher rates of clinic visits, hospitalisations and deaths.
Immediately following a flu infection, the risk of heart attack is elevated six times[v] and that of pneumonia by up to 100-fold.,
Age increases susceptibility to infection, putting older adults most at risk for flu infection and serious complications.
People with diabetes are 3 to 6 times more likely to be hospitalised due to influenza,, because the flu can make it harder to control blood sugar.
Children have a high influenza transmission risk and the highest risks of severe complications are in children younger than 2 years old.
Public health guidelines recommend annual influenza vaccination for high-risk groups.
The World Health Organization urges member states to reach a minimum 75% influenza vaccine coverage among high-risk groups – including people aged 65 and more, pregnant women, people living with diabetes, asthma, chronic heart and lung diseases, children aged 6 months to 5 years, and healthcare workers.
The US Centers for Disease Control and Prevention (CDC) recommends that everyone 6 months old and older should get an influenza vaccine every season.
In the new 2019-2030 Global Influenza Strategy, the WHO recognises the value of flu prevention in the fight against other global health threats, including non-communicable diseases and antibiotic resistance.
Annual influenza vaccination is the most effective way to protect against flu infection and its complications.
Safe and effective vaccines are available and have been used for more than 80 years to help prevent the flu and reduce the risks of its severe consequences.
When healthy adults get vaccinated, it may provide herd immunity, helping to protect more at-risk populations.
At current levels in Asia, we are far from achieving the World Health Organisation’s target of annual flu vaccination for high-risk groups.
The World Health Organization recommends influenza vaccination for vulnerable populations such as health workers and older adults as a priority target group, to protect them against flu infection and related complications during the current COVID-19 pandemic.,
Find out more about Influenza and reducing its burden through vaccination.
 World Health Organization (WHO). (2018). Influenza (Seasonal). Retrieved from:
 Kwong, JC. et al. (2018). Acute myocardial infarction after laboratory-confirmed influenza infection. New England Journal of Medicine 378:345-53.
 Metersky M.L., Masterton R.G., Lode H., File T.M. Jr., Babinchak T. (2012). Epidemiology, microbiology, and treatment considerations for bacterial pneumonia complicating influenza. Int J Infect Dis. 2012;16:e321–331. Retrieved from:
Shrestha S., Foxman B., Berus J., Van Panhuis W.G., Steiner C., Viboud C. & Rohani P. (2015). The role of influenza in the epidemiology of pneumonia. Sci Rep. 2015;5:15324. Retrieved from:
 Gozalo P.L., Pop-Vicas A., Feng Z., Gravenstein S., Mor V. (2012). The effect of influenza on functional decline. J Amer Geriatr Soc. 2012 Jul;60(7):1260-7. Epub 2012 Jun 21. PMID: 22724499. Retrieved from:
 Bouter K. P., Diepersloot R. J., Romunde L. K., Uitslager R., Masurel N., Hoekstra J. B., & Erkelens D. W. (1991). Effect of epidemic influenza on ketoacidosis, pneumonia and death in diabetes mellitus: A hospital register survey of 1976–1979 in The Netherlands. Diabetes Research and Clinical Practice, 12(1), 61-68. Retrieved from: Last accessed November 2019.
 Centers for Disease Control and Prevention (CDC). Flu and people with diabetes. Available at Last accessed November 2019.
 Centers for Disease Control and Prevention (CDC). Protect against Flu: Caregivers of infants and young children. Available at www.cdc.gov/flu/highrisk/infantcare.htm. Last accessed February 2020.
 World Health Assembly (WHA). (2003). Prevention and control of influenza pandemics and annual pandemics. Resolution 56.19. Fifty-six WHA. Available at Last accessed November 2019.
 World Health Organization (2012). Weekly epidemiological record. Vaccines against influenza WHO position paper, 87, No. 47 p461-476. Available at Last accessed November 2019.
 Centers for Disease Control and Prevention (CDC). Who needs a flu vaccine and when. Available at Last accessed February 2020.
 World Health Organization. Global Influenza Strategy 2019-2030. Available at Last accessed August 2019.
 World Health Organization. Influenza (Seasonal) factsheet. Available at Last accessed November 2019.
 Fine PEM, Mulholland K, Scott JA, et al. 77 - Community Protection. In: Orenstein WA, Offit PA, Edwards KM, eds. Plotkin's Vaccines (7th Edition): Elsevier; 2018:1512-1531.e1515
 Gupta, Vinay et al. (2012) Influenza Vaccination Guidelines and Vaccine Sales in Southeast Asia: 2008–2011. PLOS One 2012; 7(12). Available at Last accessed October 2019.