Tag: Announcements

Onsite Health’s Announcements Hub

We Are Finished Taking Bookings for Workplace Flu Vaccinations

Written by Onsite Health Team on June 25, 2026. Posted in News. No Comments on We Are Finished Taking Bookings for Workplace Flu Vaccinations

We have now finished taking bookings for our 2026 workplace flu vaccination season. Each year, there comes a point when onsite clinic availability closes and we shift our full focus to completing the remaining booked visits.

Why workplace flu vaccination timing matters

Workplace flu vaccination works best when it is planned early. In New Zealand, the flu vaccine is available from 1 April each year, before winter starts. Health New Zealand recommends annual flu vaccination for everyone over 6 months of age. Healthify also notes that it takes about two weeks for the flu vaccine to become most effective. That is why many employers aim to organise vaccination before winter pressure builds across their teams.

Flu season in Aotearoa New Zealand usually runs from May to October. During this period, workplaces often see more staff illness, more disruption, and more pressure on rosters and day to day operations. Influenza spreads quickly through shared environments, including offices, warehouses, customer facing workplaces, staff rooms, and meeting spaces.

Why we stop taking bookings before the season ends

The wider influenza immunisation programme continues well beyond early winter. Healthify states that the influenza immunisation programme runs from 1 April to 31 December. Even so, an onsite workplace vaccination service has its own operational limits. There comes a point in the season when remaining clinic time needs closing as winter influenza viruses are circulating in the community and vaccination is of less benefit.

Closing bookings before the very end of the winter vaccination period helps us deliver the remaining clinics properly and safely.

Why employers still prioritise flu vaccination

Many employers offer flu vaccination to their staff because it is a simple way to support worker health through winter. The Immunisation Advisory Centre says annual influenza immunisation is recommended for everyone who can be vaccinated, and it notes that many employers offer the vaccine to staff. This fits with what we see each year. Businesses want to reduce barriers, make vaccination easier to access, and help their people prepare before flu spreads more widely.

The flu vaccine is updated each year to match the strains most likely to circulate in New Zealand. Healthify explains that you need a flu vaccine every year because the vaccine is made to match the strains likely to be in Aotearoa New Zealand, and because protection becomes less over time.

What this means for businesses now

For businesses that already have a booking with us, your clinic will continue as planned. We will keep working through our remaining workplace visits as we finish the season.

For businesses that missed out this year, the best next step is to plan earlier for 2027. The most useful workplace flu vaccination programmes are usually the ones organised well before winter demand becomes compressed. Early planning gives more choice around timing, better internal communication with staff, and a better chance of vaccinating people before winter flu exposure rises. Email Onsite Health at mail@onsitehealth.co.nz and we will add you to our database to contact early next year.

This matters because winter is when people are most likely to come into contact with influenza, and the vaccine needs time to work. Booking early helps line up workplace access with the period when vaccination is most useful.

Looking ahead to next season

Flu vaccination remains one of the most practical seasonal health steps a workplace can support. It helps protect staff, supports business continuity, and reduces some of the pressure that winter illness can place on teams. While we are no longer taking new bookings for our 2026 workplace flu vaccinations, the value of planning ahead remains clear.

If your business missed the booking window this year, now is a good time to note it for next season. Early action gives the best chance of securing a workplace flu vaccination clinic during the most useful part of the winter vaccination period and after flu vaccines become available at the start of April each year.

References

Health New Zealand. (2025, August 7). Flu (influenza).

Health New Zealand. (2025, November 19). Flu (influenza) vaccine.

Healthify. (n.d.). Influenza vaccine, adults.

Healthify. (n.d.). Influenza vaccine, common questions.

Immunisation Advisory Centre. (n.d.). Influenza.

Immunisation Advisory Centre. (2025, March 6). Influenza vaccine.

Subclade K and Why the Flu Vaccine Still Helps Protect You

Written by Onsite Health Team on May 21, 2026. Posted in Education. No Comments on Subclade K and Why the Flu Vaccine Still Helps Protect You

You may have seen reports about subclade K, a newer influenza A(H3N2) variant that drove a strong Northern Hemisphere flu season. It has also been referred to in media reports as “super K”. That kind of headline can make people wonder if the flu vaccine is still worth having. The short answer is yes. Current New Zealand guidance still recommends annual flu vaccination, and Health New Zealand says the 2026 Southern Hemisphere vaccine available in New Zealand includes coverage for circulating A(H3N2) variants, including strains related to subclade K.

What subclade K is

Subclade K is a branch of the influenza A(H3N2) virus. Influenza viruses change often, which is why vaccine strains are reviewed and updated every year. The Eurosurveillance study deleted looked at the early 2025 to 2026 flu season in England, where influenza A(H3N2) subclade K became the dominant strain early in the season. The paper also noted that this variant showed antigenic differences from the vaccine strain used in that Northern Hemisphere season.

That sounds worrying, but it does not mean the vaccine stopped working. It means scientists needed to measure how much real world protection remained, especially against more serious illness.

What the research found

A 2025 study published in Eurosurveillance examined the early flu season in England during autumn 2025, when influenza A(H3N2) subclade K was the dominant circulating strain, to assess how well the seasonal flu vaccine was still protecting people against more serious illness.

The main value of this study is that it looked at real world vaccine effectiveness, not just laboratory matching. Even though subclade K differed from the vaccine strain in antigenic testing, the researchers still found meaningful protection against influenza linked emergency department attendance and hospital admission.

That is an important clinical point. Flu vaccines do not need to stop every infection to be useful. Reducing severity, lowering the chance of hospital care, and helping protect people at higher risk are all worthwhile outcomes. This is especially relevant for H3N2 seasons, because H3N2 strains are often linked with more severe illness in older adults.

What this means for New Zealand

New Zealand is not using the exact same seasonal flu vaccine that England used in autumn 2025. Our 2026 Southern Hemisphere vaccine was selected later, using updated international surveillance and regional expert review. Medsafe says the Australian Influenza Vaccine Committee, with a New Zealand representative, consulted on the 2026 vaccine composition for New Zealand, Australia and South Africa in October 2025. For 2026, the recommended H3N2 components are A/Singapore/GP20238/2024 like virus for egg based vaccines and A/Sydney/1359/2024 like virus for cell based, recombinant based, or nucleic acid based vaccines.

Health New Zealand has also made the local message very clear. Its flu vaccine guidance states that the 2026 Southern Hemisphere influenza vaccine available in New Zealand includes coverage for circulating A(H3N2) variants, including strains related to subclade K. That does not mean perfect protection against every infection. It does mean the vaccine has been updated with current strain information in mind, and it remains the best available tool for reducing flu risk this winter.

Why vaccination still matters

The flu vaccine helps in more than one way. It can reduce the chance of infection, but even when infection happens, it may lower the severity of illness. That is one reason public health advice still backs vaccination during seasons where the virus has changed. Health New Zealand says the flu virus changes often, which is why the vaccine is adjusted each year. The Immunisation Advisory Centre also notes that there are four influenza vaccines available in New Zealand for 2026, including egg based, cell based, and adjuvanted options.

This matters most for people who are more likely to become seriously unwell, including older adults, pregnant women, young children, and people with long term health conditions. Healthify notes that the flu can cause serious illness, especially in young children, older adults, and people with long term health problems.

The practical takeaway

The research on subclade K gives a useful message for New Zealand. Even when an H3N2 strain has drifted away from the vaccine strain in laboratory testing, the vaccine can still provide meaningful real world protection, especially against more serious illness. For New Zealanders, that sits alongside current local guidance that the 2026 vaccine includes coverage for circulating H3N2 variants related to subclade K.

So if you have seen headlines about subclade K and wondered whether the flu vaccine still helps, the evidence points in a practical direction. Yes, it does. It may not stop every case, but it remains one of the best ways to lower your risk of severe flu this winter.

References

Health New Zealand. (2025, November 19). Flu (influenza) vaccine.

Healthify. (n.d.). Influenza vaccine, adults.

Immunisation Advisory Centre. (2026). Influenza immunisation programme.

Immunisation Advisory Centre. (2026). Influenza vaccine.

Kirsebom, F. C. M., Andrews, N., Tessier, E., et al. (2025). Early influenza virus characterisation and vaccine effectiveness in England in autumn 2025, a period dominated by influenza A(H3N2) subclade K. Eurosurveillance, 30(46), Article 2500854.

Medsafe. (2025, November 10). Influenza vaccine composition.

young woman making booking taking notes at outdoor office space.

Don’t Miss Out on Workplace Flu Vaccinations

Written by Onsite Health Team on May 14, 2026. Posted in News. No Comments on Don’t Miss Out on Workplace Flu Vaccinations

If your business has not booked its 2026 workplace flu vaccinations yet, now is the time to act. We are finishing our workplace flu vaccination season in June, so the booking window is narrowing. For many businesses, this is the last chance to organise an onsite clinic.

Why workplace vaccination is still worth booking

In New Zealand, flu season usually runs from May to October. That means winter exposure is already underway, and workplaces that delay much longer risk missing the best practical window to vaccinate staff through a workplace clinic.

Flu spreads quickly through shared work environments. Offices, warehouses, retail teams, hospitality venues, healthcare settings, and transport based roles all bring people into close contact. Health New Zealand says influenza spreads from person to person through touch and droplets in the air, including coughing, sneezing, and talking. Once one staff member brings flu into the workplace, it can move through a team quickly.

Workplace vaccination remains one of the most practical ways to reduce that risk. The Immunisation Advisory Centre states that annual flu immunisation is recommended for everyone who can be vaccinated, and also notes that many employers offer the vaccine to their staff. From a business point of view, onsite delivery makes access easier, reduces the need for staff to book separate appointments, and helps improve uptake across the team.

Our 2026 workplace vaccination season is nearly finished

We are now in the final part of our workplace vaccination season, and we will be finishing our onsite flu vaccinations in June. We are not closing on one fixed public date, because clinic availability depends on remaining capacity and scheduling, but the season is coming to a close.

That means businesses that still want an onsite workplace clinic should not leave it too long. Once our June appointments are full, the remaining options become more limited. For some employers, that may mean relying on individual staff to arrange vaccination elsewhere, rather than having the convenience of an organised workplace clinic.

Why acting now helps your team

Booking now gives your staff the best chance to receive vaccination while winter is still in front of us. Even though the national influenza immunisation programme runs beyond mid year, the best time for a workplace clinic is generally before winter demand and staffing pressures make planning harder. Healthify says it is best to get the flu vaccine as soon as you can, because winter is when people are most likely to come into contact with influenza.

This is especially important for teams that include staff at higher risk of complications, including older adults, pregnant women, and people with certain long term health conditions. Health New Zealand continues to recommend annual flu vaccination for everyone over six months of age, with funded access for eligible groups.

A practical step before the season moves on

Flu vaccination is one of the simplest seasonal health steps a business can take. It supports staff wellbeing, reduces barriers to vaccination, and helps workplaces respond early rather than waiting for illness to disrupt operations. We are still vaccinating, but only for a limited time as we move through June.

If your business has been meaning to organise workplace flu vaccinations for 2026, this is the time to do it. Do not miss out on the last part of the season while clinic space is still available.

References

Health New Zealand. (2025, August 7). Flu (influenza).

Health New Zealand. (2025, November 19). Flu (influenza) vaccine.

Health NZ. (2026, April 2). Health NZ urges people to get vaccinated ahead of winter.

Healthify. (n.d.). Influenza vaccine, adults.

Immunisation Advisory Centre. (2025, March 6). Influenza vaccine.

Immunisation Advisory Centre. (2026). Influenza immunisation programme.

Immunisation Advisory Centre. (n.d.). Influenza.

handing over voucher or prescription at a pharmacy to a pharmacist

Onsite Health Begins Sending 2026 Flu Vouchers to Clients

Written by Onsite Health Team on April 23, 2026. Posted in News. No Comments on Onsite Health Begins Sending 2026 Flu Vouchers to Clients

Our 2026 flu vouchers started going out to clients at the beginning of April. In New Zealand, flu vaccines become available from 1 April each year, and annual vaccination is recommended before or during the winter flu season. Protection is not instant, it usually takes about two weeks for the body to build a good immune response after vaccination. Sending vouchers early helps employers give staff enough time to get protected before flu activity builds through winter.

Why we send 2026 flu vouchers in April

Health New Zealand advises that the flu vaccine is available from 1 April, and recommends yearly flu vaccination for everyone aged over 6 months. The Immunisation Advisory Centre also advises annual vaccination because influenza strains change, and the vaccine is updated to match the strains most likely to circulate.

From a clinical point of view, early vaccination is practical. The aim is to have protection in place before flu spreads widely through workplaces, households, schools, and public spaces. For businesses, that matters because influenza can move quickly through teams and lead to several staff being away at the same time.

Who 2026 flu vouchers are for

Flu vouchers are useful for staff who cannot attend an onsite workplace vaccination clinic. That includes people working from home, staff who travel, employees based in other regions, and anyone who is away on the day of the workplace visit. They also suit organisations with smaller teams, or those spread across more than one site.

This is one of the practical strengths of a voucher programme. A business may run an onsite clinic for head office staff, while also giving vouchers to people in regional offices or remote roles. That helps employers extend coverage across the wider team, rather than limiting access to one location or one day. Onsite Health’s flu voucher offering is designed for this kind of nationwide staff coverage.

How Onsite Health distributes flu vouchers

We send flu vouchers to the client, not directly to individual staff members. This gives employers more control and flexibility over how vouchers are shared across their team. A business can decide who needs a voucher, when it should be sent, and how it should be distributed internally. This works well for organisations with a mix of office based staff, remote workers, travelling employees, or teams spread across different locations. It also makes it easier to manage last minute changes, staff absences, and new starters. By sending vouchers to the client for internal distribution, we help keep the process simple, practical, and easy to manage.

Where staff can redeem flu vouchers

Our 2026 flu vouchers can be redeemed at selected GP surgeries and vaccinating Unichem and Life Pharmacies throughout New Zealand. This gives staff a simple option close to home or work, rather than needing to travel to a main office for vaccination. For employers with teams in more than one city, this makes planning easier and more inclusive.

Vouchers are emailed directly to the client for internal distribution to staff. This keeps the process simple and allows employers to send them to the right people quickly. There is also no minimum number required to purchase flu vouchers, which makes them a practical option for both small and large teams.

How flu vouchers support nationwide staff coverage

Many New Zealand businesses no longer work from one central office. Some teams are hybrid, some are fully remote, and some are spread across regional branches. A flu voucher programme helps employers respond to that change in a practical way.

From a health point of view, wider vaccine access improves the chance that more staff will be vaccinated before winter peaks. Many employers already support flu vaccination because it helps reduce the risk of severe illness and can lower disruption during winter. Easier access usually supports better uptake. When people can get vaccinated in their own area, at a pharmacy or clinic that suits them, there are fewer barriers around time, travel, and logistics.

This approach also gives staff flexibility. Some people may miss an onsite clinic because of leave, meetings, travel, or shift patterns. A voucher gives them another way to be included, increasing workforce coverage.

A practical step before winter

Sending 2026 flu vouchers in April is a simple but important part of winter planning. It matches the start of the New Zealand flu vaccination season, supports timely protection, and helps employers reach staff across different locations. For many organisations, vouchers are not a replacement for onsite clinics, but an added layer of access.

Sources

Health New Zealand, Te Whatu Ora. (2025, November 19). Flu (influenza) vaccine.

Health New Zealand, Te Whatu Ora. (2026, April 2). Health NZ urges people to get vaccinated ahead of winter.

Immunisation Advisory Centre. (2025, March 6). Influenza vaccine.

Immunisation Advisory Centre. (n.d.). Influenza.

pleased-nurse-with-her-suitcase-looking-away

Onsite Health is Now Vaccinating Across Auckland

Written by Onsite Health Team on April 16, 2026. Posted in News. No Comments on Onsite Health is Now Vaccinating Across Auckland

Workplace flu vaccinations have started for 2026

We have now started providing 2026 flu vaccinations across Auckland. Our workplace clinics began at the start of April, which gives Auckland businesses the chance to protect staff before flu activity builds through winter. We are taking bookings for the rest of the season, which lasts until June.

Flu protection is not immediate. The flu vaccine usually takes up to two weeks to build good protection, which is why vaccination is recommended before or during the early part of the New Zealand flu season. Health New Zealand and the Immunisation Advisory Centre both advise annual flu vaccination because influenza viruses change regularly and the vaccine is updated each year to match the strains expected to circulate.

Why timing matters for Auckland workplaces

In New Zealand, flu is most common during winter. It spreads easily through coughing, sneezing, and close contact. In busy offices, warehouses, customer facing workplaces, and shared staff areas, one case can quickly become several. That can mean disruption, sick leave, and pressure on teams during an already busy part of the year.

That is why we start workplace flu vaccinations in April. Vaccinating early helps staff build protection before influenza spreads more widely in the community. It also gives employers more choice around booking dates and helps avoid the rush that often comes later in autumn and early winter.

How our workplace vaccination service works

We keep the process simple and practical. After a workplace books with us, we confirm the date, time, site details, and expected staff numbers. We then attend the workplace and provide vaccinations onsite through an authorised vaccinator. Staff complete consent before vaccination, and we advise a 15 minute post vaccination wait period afterwards.

This approach helps remove common barriers. Staff do not need to arrange separate appointments, drive to a clinic, or take extra time out of the day. Making flu vaccination easy usually improves uptake, which is important in workplaces where higher participation can help reduce the spread of infection between colleagues. The Immunisation Advisory Centre notes that many employers offer flu vaccination to staff as part of good winter health planning.

Vaccine options for 2026

For 2026, we are offering two flu vaccine options, a traditional egg based vaccine and Flucelvax®, which is a cell based vaccine. Both are designed to protect against the influenza strains expected to circulate during the coming winter.

The 2026 vaccine strains reflect the World Health Organization recommendation for the Southern Hemisphere season. As with every year, the strain mix has been updated because influenza viruses change over time. This annual update is one reason a flu vaccination is recommended each year, even for people who had one last winter.

Workplace flu vaccinations across Auckland

We provide workplace flu vaccinations across Auckland, including key business areas and larger employment hubs such as Auckland CBD, Newmarket, Parnell, Grafton, Penrose, Mount Wellington, Ellerslie, Greenlane, Onehunga, East Tamaki, Highbrook, Mount Eden, Albany, Takapuna, Rosedale, Wairau Valley, Henderson, Westgate, Airport Oaks, Māngere, and Manukau.

If you are looking to book workplace flu vaccinations across Auckland, we can arrange an onsite clinic at your workplace and help make the process simple for your team. Feel free to reach out to us if you are not sure if we cover your Greater Auckland location.

Support for remote and flexible teams

Not every employee is in the office on vaccination day. Some work remotely, are travelling, or are based outside Auckland. To support these staff, we also offer flu vouchers that can be redeemed at selected clinics and pharmacies across New Zealand. This gives employers a practical way to include more of their team in the vaccination programme, even when staff are spread across different locations.

Don’t miss out on protecting your staff this winter

Annual flu vaccination remains one of the most effective ways to reduce the risk of influenza and its complications. It also supports staff wellbeing and helps workplaces prepare for the winter months with less disruption.

We have already started our 2026 workplace flu vaccinations across Auckland. If your business is planning ahead for winter, now is a good time to book. Reach out to our friendly team to organise a date and time that is right for your staff.

Sources

Health New Zealand. (2025, November 19). Flu (influenza) vaccine.

Health New Zealand. (2025, August 7). Flu (influenza).

Immunisation Advisory Centre. (2025, March 6). Influenza vaccine.

Immunisation Advisory Centre. (2025). Influenza.

Immunisation Advisory Centre. (2026, February 16). Guidelines for post-vaccination wait times.

People scheduling flu vaccination appointments

Onsite Health Now Taking 2026 Flu Vaccination Bookings

Written by Onsite Health Team on February 19, 2026. Posted in News. No Comments on Onsite Health Now Taking 2026 Flu Vaccination Bookings

We are now taking bookings for 2026 workplace flu vaccinations across Auckland. If you are planning ahead for the New Zealand Flu Season, now is the time to act. Employers who book early secure their preferred dates and ensure staff receive protection before winter peaks.

The Ministry of Health advises that influenza vaccination is the best way to reduce the risk of severe illness and hospitalisation. Vaccination also reduces disruption in workplaces during winter.

If you are looking to book workplace flu vaccinations in Auckland, we have opened our 2026 schedule.

NZ flu season timeline for 2026

Planning around the New Zealand Flu Season is important. Influenza activity usually increases from May and continues through winter, often peaking between June and August according to Health New Zealand.

We began taking bookings shortly after Waitangi Weekend. This allows employers to secure dates well before the winter rush.

We begin providing workplace flu vaccinations from early April. We also start issuing flu vouchers to clients in early April for remote staff or those who cannot attend onsite clinics.

The optimal time to receive a flu vaccination is April and May (Immunisation Advisory Centre). Protection develops around two weeks after vaccination. Early vaccination ensures immunity is in place before influenza spreads widely in the community.

Demand increases rapidly through May. Many workplaces aim to complete vaccinations before June. We usually finish taking bookings for onsite workplace visits at some point in June. Booking early reduces the risk of missing out on preferred dates and optimal immunity coverage for your staff.

How the workplace flu vaccination process works

Our process is simple and designed to minimise disruption to your workplace.

1. Contact us

After you contact us, we will organise a suitable time for one of our Vaccinator to visit your workplace. We confirm the number of staff and discuss any site specific requirements.

2. Preparation

Before the visit, you will receive confirmation of the date and time. We provide posters and pamphlets to promote the clinic internally. We also send reminder emails to the organiser. Clear communication improves attendance and reduces last minute questions.

3. On the day

Our Vaccinator arrives prior to the agreed time with all required clinical equipment. Staff complete a consent form before vaccination.

We require a first aid certified staff member to be present onsite during the clinic. This ensures workplace health and safety requirements are met. Vaccination is administered by an authorised vaccinator in line with Ministry of Health guidelines. The process is efficient and usually takes only a few minutes per person.

4. After vaccination

Staff are advised to remain onsite for at least 15 minutes after receiving the vaccine. This allows monitoring for any immediate reactions, which are uncommon. Our Vaccinator remains onsite for 15 minutes after the last vaccination has been given.

For staff who are absent on the day, flu vouchers can be ordered. These vouchers allow employees to receive their vaccination at selected GP clinics or pharmacies across New Zealand.

Why book early for 2026

Early vaccination means better protection. The Ministry of Health recommends annual influenza vaccination because influenza strains change each year and immunity from previous seasons declines over time. Protection takes around two weeks to develop after vaccination, so receiving the vaccine in April or May allows immunity to build before winter transmission increases. When staff are vaccinated before influenza begins circulating widely, workplaces are better protected during peak months.

Demand for workplace flu vaccinations increases quickly once flu cases begin appearing in the media and in local communities. Each year we see a sharp rise in booking requests during May. Organisations that delay often find their preferred dates are no longer available. Booking early for 2026 reduces pressure later in the season and ensures vaccination can be completed at the most effective time.

Early planning also supports staff awareness. When employers communicate vaccination dates well in advance, uptake improves. Higher participation reduces the likelihood of workplace outbreaks and staff sick leave.

Taking action before winter protects productivity, reduces unexpected absence, and supports staff wellbeing throughout the 2026 New Zealand Flu Season.

To book workplace flu vaccinations across Auckland, contact Onsite Health today and secure your 2026 vaccination date before our schedule fills.

Close up of a gloved hand holding a vaccine vial in a clinical setting, representing immunisation, healthcare, and flu prevention.

2026 Southern Hemisphere Influenza Vaccine Composition

Written by Onsite Health Team on October 25, 2025. Posted in News. No Comments on 2026 Southern Hemisphere Influenza Vaccine Composition

The World Health Organisation confirmed on 26 September 2025 the recommended influenza vaccine strains for the 2026 Southern Hemisphere season. These recommendations directly shape the vaccines used during the New Zealand Flu Season.

Influenza viruses change every year. Small genetic changes can make the virus harder for our immune system to recognise. Because of this, the flu vaccine is reviewed and updated annually. This is why we recommend vaccination each year, even if you received one last winter.

For the 2026 New Zealand Flu Season, WHO recommends the following strains:

Cell based vaccines for 2026 include:

an A/Missouri/11/2025 (H1N1)pdm09-like virus;
an A/Sydney/1359/2024 (H3N2)-like virus; and
a B/Austria/1359417/2021 (B/Victoria lineage)-like virus

Cell based vaccines are produced using cultured mammalian cells rather than fertilised chicken eggs. This method avoids egg adaptation changes and may improve how closely the vaccine matches the circulating virus, particularly for H3N2 strains.

Egg based vaccines for 2026 include:

an A/Missouri/11/2025 (H1N1)pdm09-like virus;
an A/Singapore/GP20238/2024 (H3N2)-like virus; and
a B/Austria/1359417/2021 (B/Victoria lineage)-like virus.

Egg based vaccines have been safely used for more than 70 years. They remain an effective and well established option for protecting people during the New Zealand Flu Season.

The key difference between the two vaccine types this year is the H3N2 component. This reflects how each virus strain grows in the manufacturing process. Both vaccine types protect against three main influenza strains expected to circulate.

Why B Yamagata Is No Longer Included

WHO continues to advise that a B Yamagata lineage strain is no longer required in routine influenza vaccines. Surveillance data shows this strain has not circulated globally for several seasons. Some quadrivalent vaccines may still include a fourth B Yamagata strain while countries transition to trivalent vaccines.

Why Vaccine Strains Change Each Year

The 2026 vaccine strains differ from those used in 2025, and they also differ from the strains recommended for the 2025 to 2026 Northern Hemisphere season. This change is deliberate. Influenza viruses are unstable by nature. They undergo frequent genetic changes through processes known as antigenic drift. These small mutations can alter surface proteins on the virus, particularly haemagglutinin and neuraminidase, which are the main targets of our immune response. Even minor changes can reduce how well immunity from a previous infection or vaccination recognises the virus the following year.

Because of this constant viral evolution, the World Health Organisation carries out global influenza surveillance throughout the year. More than 150 national influenza centres across over 100 countries collect respiratory samples. Laboratories sequence viruses, identify emerging variants, and share findings through the Global Influenza Surveillance and Response System. Hospital data is reviewed to assess severity, age distribution, and complication rates. Public health agencies also analyse vaccine effectiveness from the most recent season to understand how well protection held up against circulating strains.

Twice a year, technical advisory groups meet to review this data. In late September, WHO issues its formal recommendation for the Southern Hemisphere influenza vaccine composition. This timing is critical. Most influenza vaccines require six to eight months for regulatory approval, large scale manufacturing, quality control testing, packaging, and global distribution. Manufacturers must grow and process vaccine viruses, confirm stability and safety, and prepare hundreds of millions of doses for countries including New Zealand.

This structured timeline ensures vaccines are available before the New Zealand Flu Season begins, which typically runs from May through September, with peak transmission in winter. Without annual updates to vaccine composition, protection would gradually weaken as circulating strains drift further from older vaccine strains. Regular reformulation remains essential to maintain vaccine effectiveness, reduce hospitalisation, and protect public health both in New Zealand and worldwide.

What This Means for You

The annual update process is designed to give New Zealanders the best possible protection against influenza each winter. Flu vaccination reduces the risk of severe illness, hospitalisation, and complications such as pneumonia. It also reduces the likelihood of spreading influenza to vulnerable people, including older adults, pregnant women, young children, and those with chronic medical conditions.

Even in seasons where circulating strains vary slightly from predictions, vaccination remains the most effective tool we have to reduce serious outcomes.

WHO recommendations form the basis for national regulatory approvals and vaccine supply planning worldwide. Regular strain updates are essential for maintaining vaccine effectiveness and protecting public health during every New Zealand Flu Season.

For full technical details, read the WHO report (dated 26 September 2025) linked here.