Flu Isn’t “Just a Virus”, It Can Lead to Serious Complications

Apr, 2026

Many people still think of flu as something you can push through. That view misses the real risk. Influenza is a serious viral infection that can lead to complications, hospital admission, and in some cases death. Health New Zealand says some people get very sick with flu, and around 500 people die from it each year in New Zealand.

Why flu can become serious

Flu affects more than the nose and throat. It can spread through the respiratory tract and place real stress on the body. The Immunisation Advisory Centre notes that influenza can lead to serious complications including bronchitis, pneumonia, heart failure, worsening asthma, miscarriage, and death in some groups. That is a key reason everyone should take influenza seriously every winter.

One of the most important, and common, complications is pneumonia. Flu can inflame the airways, weaken normal defences in the lungs, and make it easier for other infections to take hold. Lower respiratory tract infections such as pneumonia are more serious than upper respiratory infections, and pneumonia can lead to severe illness and hospital care.

Recap: Influenza can:

Directly infect the lungs
Damage airway defences
Make it easier for bacteria to cause secondary infections

This significantly increases the risk of:

Hospitalisation
Severe illness
Death in vulnerable groups

Who is more likely to have complications

Flu does not affect everyone in the same way. People at higher risk of complications include pregnant women, older adults, and people with long term conditions such as heart disease, diabetes, and asthma. Having influenza during pregnancy carries a higher risk of serious complications, including premature birth, low birthweight, miscarriage, or stillbirth if flu occurs during pregnancy.

The Immunisation Advisory Centre also highlights people who are immunocompromised as being at higher risk of severe influenza and complications. This matters in everyday settings because someone may look well at work, on public transport, or at a family event, but still be more vulnerable to serious illness than others around them.

Recap: Higher-risk groups are more likely to experience:

Severe infection
Complications like pneumonia
Hospital admission

When more than one virus is circulating

Winter illness is not only about influenza. COVID 19, and RSV all circulate through winter and place pressure on emergency departments, hospitals, GPs, and community services. These viruses can all cause more severe illness in babies and young children, pregnant people, older adults, and people with weakened immune systems.

That matters because people are often exposed to more than one respiratory virus in the same season. Even when we are not talking about confirmed co infection in every case, the overall burden rises when several viruses are circulating at once. RSV can itself cause serious complications, including pneumonia, and COVID 19 can also make some people very unwell. When flu is added into that mix, recovery can be harder and the risk picture becomes more serious, especially for higher risk groups.

Recap: When co-infection occurs:

Illness severity increases
Recovery becomes more difficult
Risk of complications rises

Why prevention matters

Prevention matters because flu spreads quickly through households, workplaces, schools, and the wider community. Flu vaccines are available from 1 April 2026 ahead of the winter season. Vaccinating before winter helps reduce the chance of infection and lowers the risk of severe illness and complications if infection does happen. It also helps protect whānau and reduces pressure on health services during the busiest respiratory months of the year.

The flu vaccination is more than a personal choice

Flu prevention is not only about the person getting vaccinated. It also helps protect the people around them. Immunisation supports both individual and community protection. That matters in workplaces, aged care settings, health services, and homes where vulnerable people may be exposed to infection brought in by others.

Flu is easy to underestimate because it often starts with familiar symptoms. The complication risk is what changes the picture. Pneumonia, worsening long term conditions, pregnancy related complications, and severe winter illness are all real outcomes seen in New Zealand.

Contact us to book your yearly flu vaccine, which remains one of the simplest and most effective ways to lower that risk for you, your staff, and those in your life.