Understanding Influenza
Influenza, commonly known as the flu, is a contagious respiratory illness caused by influenza viruses. These viruses infect the nose, throat, and sometimes the lungs, and they spread easily from person to person through respiratory droplets released when an infected individual coughs, sneezes, or speaks.
Although many people recover within several days, influenza can still cause significant illness and complications, particularly among vulnerable populations.
Each year, seasonal influenza affects millions of people worldwide and contributes to increased healthcare visits, workplace absenteeism, and disruptions to daily activities.
Because influenza viruses evolve continuously, annual vaccination remains the most effective preventive measure against seasonal influenza infection.
How Influenza Spreads
Influenza viruses spread primarily through respiratory droplets. When an infected individual coughs, sneezes, or talks, virus-containing droplets can reach nearby people or contaminate surfaces.
Common ways influenza spreads include:
- Close contact with infected individuals
- Shared workspaces and crowded environments
- Touching contaminated surfaces and then touching the face
Because workplaces and shared environments bring people into close contact, influenza can spread rapidly once an outbreak begins.
Why Annual Flu Vaccination Is Recommended
Influenza viruses change frequently through natural mutations. Because of these changes, immunity from previous infections or vaccinations may gradually decline.
The World Health Organization monitors circulating influenza viruses through an international surveillance network and updates vaccine composition recommendations every year.
For the 2026 influenza vaccination season, the WHO recommends vaccines that include protection against:
- A(H1N1)pdm09-like virus
- A(H3N2)-like virus
- B/Victoria lineage virus
Receiving the flu vaccine annually helps ensure protection against the virus strains most likely to circulate during the upcoming season.
Who Should Get the Flu Vaccine
Influenza vaccination is recommended for most individuals, particularly those who may be at higher risk of complications from infection.
Priority groups include:
- Pregnant women
- Healthcare workers
- Adults aged 65 years and older
- Children aged 6 months to 5 years
- Individuals with chronic medical conditions, including:
- Diabetes
- Heart disease
- Chronic lung disease
- Kidney disease
- Immunocompromised conditions
Vaccination helps reduce both the risk of infection and the severity of illness.
Flu Vaccination in the Philippines
In tropical countries such as the Philippines, influenza may circulate throughout the year. However, increases in influenza activity may occur during periods when respiratory infections become more common.
Because influenza does not follow a strict winter pattern in tropical climates, vaccination can still be beneficial at different times of the year.
Healthcare providers often recommend vaccination before periods when influenza activity may increase, allowing the body time to develop immunity.
Types of Flu Vaccines
Seasonal influenza vaccines may come in different formulations depending on the number of virus strains included.
Trivalent Flu Vaccine
Trivalent influenza vaccines protect against three influenza virus strains:
- Influenza A(H1N1)
- Influenza A(H3N2)
- Influenza B (Victoria lineage)
Recent global health guidance has emphasized trivalent vaccines because the B/Yamagata lineage virus has not been detected worldwide for several years.
Quadrivalent Flu Vaccine
Quadrivalent influenza vaccines protect against four influenza virus strains:
- Influenza A(H1N1)
- Influenza A(H3N2)
- Influenza B (Victoria lineage)
- Influenza B (Yamagata lineage)
Although quadrivalent vaccines include an additional influenza B strain, both trivalent and quadrivalent vaccines remain safe and effective.
How the Flu Vaccine Works
Influenza vaccines stimulate the immune system to recognize specific influenza virus strains.
After vaccination, the body produces antibodies that help defend against infection if exposure occurs later.
It typically takes about two weeks after vaccination for protective immunity to develop.
Even if a vaccinated individual becomes infected, vaccination may still help reduce the severity of illness and lower the risk of complications.
Why Workplaces Offer Flu Vaccination
Influenza spreads easily in shared environments such as offices, factories, and workplaces. During flu season, employee illness can lead to:
- Increased absenteeism
- Reduced productivity
- Operational disruptions
For this reason, many organizations provide corporate flu vaccination programs as part of their workplace health initiatives.
Providing vaccination within the workplace helps protect employees while minimizing the impact of influenza outbreaks on business operations.
Corporate Flu Vaccination with Affinity Vaccines
At Affinity Vaccines, influenza vaccination services are designed specifically for on-site workplace vaccination programs.
Corporate vaccination programs may include:
- On-site flu vaccination for employees
- Organized workplace vaccination campaigns
- Professional vaccine administration by licensed healthcare providers
- Efficient scheduling for organizations of various sizes
Vaccination services follow internationally recognized medical guidance, including recommendations from the World Health Organization, and vaccines are sourced from reputable global manufacturers.
Plan Your Workplace Flu Vaccination Program Early
Organizations planning their 2026 corporate flu vaccination programs are encouraged to coordinate early to ensure vaccine availability and smooth implementation.
Early planning helps companies:
- Secure vaccine supply
- Schedule convenient vaccination dates
- Protect employees before influenza activity increases
Companies interested in organizing workplace vaccination programs may coordinate early with Affinity Vaccines to schedule their on-site corporate flu vaccination program for the upcoming influenza season.
Early preparation helps support a healthier workplace while minimizing disruptions caused by seasonal influenza.
Frequently Asked Questions
Is flu vaccination recommended every year?
Yes. Influenza viruses change over time, which is why the flu vaccine is updated annually to match circulating virus strains.
When should I get the flu vaccine in the Philippines?
Vaccination is recommended before influenza activity increases so that the body has time to develop immunity.
Is the flu vaccine safe?
Yes. Seasonal influenza vaccines undergo strict safety evaluation and are widely used around the world.
Can companies provide flu vaccination to employees?
Yes. Many organizations organize on-site workplace vaccination programs to make influenza vaccination more accessible for employees.
