Getty ImagesAs winter takes hold and more people spend time indoors, respiratory illnesses are expected to begin spreading more widely through communities.But while the seasonal return of viruses is familiar, New Zealand’s respiratory landscape is still not quite back to normal. Six years after the country closed its borders to keep COVID out, patterns of infection remain different from those seen before the pandemic.Influenza, COVID and respiratory syncytial virus (RSV) were all heavily suppressed by border restrictions, social distancing and other pandemic measures before rebounding as those controls were lifted.Since then, rates of all three viruses have fluctuated from year to year as immunity from both infection and vaccination has evolved. Influenza activity is yet to ramp up after an out-of-season surge in late 2025, driven by a fast-spreading variant. RSV has largely returned to its traditional pattern of winter peaks, while coronavirus continues to evolve into new Omicron subvariants. The result is that respiratory risks remain more complicated than they were before the pandemic. So what does this mean for people weighing up which vaccinations to get this season?Who is most at risk?The risk of COVID has also changed much from four or five years ago, when more severe coronavirus variants and major waves were sweeping through communities.Due to widespread vaccination and previous infections, most younger and otherwise healthy people now face a relatively low risk of severe illness.While some remain concerned about the continuing impact of long COVID, current evidence suggests that, with widespread population immunity from infection and vaccination, otherwise healthy adults under 65 years gain little additional protection from boosters. For older adults, however, COVID is still a serious threat. Hospitalisation rates remain highest among those aged over 65, particularly people over 80 and those with underlying health conditions. This graph shows hospital admissions for COVID-19 in New Zealand, per 100,000 cases, across age groups in people aged over 65, since 2022. While rates have declined over time, elderly patients remain at risk from coronavirus. Provided by authors, CC BY-NC-ND Influenza presents a different challenge. Unlike COVID, it changes unpredictably and can become both more severe and less well matched to existing immunity.It is also much more likely than COVID to cause serious illness in young children, with those under five years old continuing to face a significant risk of hospitalisation. This graph shows weekly recorded rates of severe acute respiratory infection from any cause, including influenza and COVID-19, in New Zealand as measured by hospital admissions per 100,000 of population. Blue denotes the current year, grey 2025 and black the 2015–19 average. Provided by authors, CC BY-NC-ND RSV shares some similarities with COVID in that it can be particularly dangerous for older and frail adults. But it also differs in one important respect: it is a major cause of hospitalisation among infants in the first year of life.In other words, while all three viruses can cause serious illness, the groups most at risk are not the same. Understanding those differences is key to deciding who stands to benefit most from vaccination and other protective measures.Who should seek vaccination?The answer depends on a person’s age and underlying health.For COVID, the strongest case for vaccination is now among older adults and people with significant medical conditions.Current New Zealand recommendations are consistent with international guidance in advising regular booster doses for people aged over 65, particularly those over 75 and those living with frailty or chronic illness.For these groups, a COVID infection that causes only mild symptoms in other people can still result in hospitalisation. Combining a COVID booster with an annual flu vaccination is a simple way to maintain protection, yet current coverage rates among older people for both are not nearly high enough.For younger and otherwise healthy adults, meanwhile, the need for COVID vaccination has changed. Updated boosters remain safe and provide additional protection, but the benefits are smaller than they were because most people now have substantial immunity from previous vaccination, infection or both.For influenza, however, the case is different. Like COVID, older adults are at highest risk of death. But, unlike COVID, children under five are also at increased risk of hospitalisation, due to the way influenza viruses have been evolving.Important changes are also coming. From 2027, all New Zealand children under five will again be eligible for funded flu vaccination, reflecting their elevated risk of hospitalisation. At the other end of the age spectrum, adults over 65 will gain access to Fluad, an enhanced vaccine designed to provide stronger protection for ageing immune systems.NZ’s RSV vaccine gapWhile COVID and influenza vaccines remain widely available in New Zealand, the country is yet to fund vaccines or protective antibody programmes targeting RSV. This is particularly significant for infants. In Australia, a funded programme providing RSV vaccination during pregnancy and/or protective antibodies to newborns dramatically reduced infant hospitalisations in its first year. RSV can also cause serious illness in older adults. While an RSV vaccine is available in New Zealand for people aged over 60, it remains unfunded and relatively expensive.By comparison, the United Kingdom began funding RSV vaccination for adults over 75 in 2024, with impressive results, and Australia is extending funded access to the same age group this year. This winter, much higher uptake of COVID and influenza vaccines among adults over 65 is needed to reduce severe disease and hospitalisation.Looking ahead, the introduction of free flu vaccination for children under five and enhanced flu vaccines for older adults is welcome.But RSV remains a major cause of hospitalisation among New Zealand infants, leaving the country increasingly out of step with other nations that have introduced funded protection programmes.Peter McIntyre has received research funding from the Ministry of Health and from United States-based philanthropy organisation FluLab.Joan Ingram is affiliated with the Immunisation Advisory Centre.Nikki Turner is principal medical advisor at Immunisation Advisory Centre, leads a research study funded by United States-based philanthropy organisation FluLab and sits on several advisory groups for Pharmac, Health NZ and the Ministry of Health.