Five years ago, COVID was all we could think about. Today, we’d rather forget about lockdowns, testing queues and social distancing. But the virus that sparked the pandemic, SARS-CoV-2, is still circulating.

Most people who get COVID today will experience only a mild illness. But some people are still at risk of severe illness and are more likely to be hospitalised with COVID. This includes older people, those who are immunocompromised by conditions such as cancer, and people with other health conditions such as diabetes.

Outcomes also tend to be more severe in those who experience social inequities such as homelessness. In the United Kingdom, people living in the 20% most deprived areas have double chance of being hospitalised from infectious diseases than those in the least deprived areas.

How many cases and hospitalisations?

In Australia, 58,000 COVID cases have been reported so far in 2025. However, testing rates have declined and not all positive cases are reported to the government, so case numbers in the community are likely much higher.

Latest data from FluCan, a network of 14 hospitals, found 781 people were hospitalised for COVID complications in the first three months of the year. This “sentinel surveillance” data gives a snapshot from a handful of hospitals, so the actual number of hospitalisations across Australia is expected to be much higher.

While deaths are lower than previous years, 289 people died from COVID-related respiratory infections in the first two months of the year.

What can we expect as we head into winter?

We often see an increase in respiratory infections in winter.

However, COVID peaks aren’t just necessarily seasonal. Over the past few years, peaks have tended to appear around every six months.

What are the most common COVID symptoms?

Typical early symptoms of COVID included fever, cough, sore throat, runny nose and shortness of breath. These have remained the most common COVID symptoms across the multiple variant waves.

Early in the pandemic, we realised COVID caused a unique symptom called anosmia – the changed sense of taste or smell. Anosmia lasts about a week and in some cases can last longer. Anosmia was more frequently reported from infections due to the ancestral, Gamma, and Delta variants but not for the Omicron variant, which emerged in 2021.

However, loss of smell still seems to be associated with some newer variants. A recent French study found anosmia was more frequently reported in people with JN.1.

But the researchers didn’t find any differences for other COVID symptoms between older and newer variants.

Should you bother doing a test?

Yes. Testing is particularly important if you experience COVID-like symptoms or were recently exposed to someone with COVID and are at high-risk of severe COVID. You might require timely treatment.

If you are at risk of severe COVID, you can see a doctor or visit a clinic with point-of-care testing services to access confirmatory PCR (polymerase chain reaction) testing.

Rapid antigen tests (RATs) approved by Australia’s regulator are also still available for personal use.

But a negative RAT doesn’t mean that you don’t have COVID – especially if you are symptomatic.

If you do test positive, while you don’t have to isolate, it’s best to stay at home.

If you do leave the house while experiencing COVID symptoms, minimise the spread to others by wearing a well-fitted mask, avoiding public places such as hospitals and avoiding contact with those at higher risk of severe COVID.

How long does COVID last these days?

In most people with mild to moderate COVID, it can last 7–10 days.

Symptomatic people can spread the infection to others from about 48 hours before you develop symptoms to about ten days after developing symptoms. Few people are infectious beyond that.

But symptoms can persist in more severe cases for longer.

A UK study which tracked the persistence of symptoms in 5,000 health-care workers found symptoms were less likely to last for more than 12 weeks in subsequent infections.

General fatigue, for example, was reported in 17.3% of people after the first infection compared with 12.8% after the second infection and 10.8% following the third infection.

Unvaccinated people also had more persistent symptoms.

Vaccinated people who catch COVID tend to present with milder disease and recover faster. This may be because vaccination prevents over-activation of the innate immune response.

Vaccination remains the best way to prevent COVID

Vaccination against COVID continues to be one of the most effective ways to prevent COVID and protect against it. Data from Europe’s most recent winter, which is yet to be peer reviewed, reports COVID vaccines were 66% effective at preventing symptomatic, confirmed COVID cases.

Most people in Australia have had at least one dose of the COVID vaccine. But if you haven’t, people over 18 years of age are recommended to have a COVID vaccine.

Boosters are available for adults over 18 years of age. If you don’t have any underlying immune issues, you’re eligible to receive a funded dose every 12 months.

Boosters are recommended for adults 65–74 years every 12 months and for those over 75 years every six months.

Adults over 18 years who are at higher risk because of weaker immune systems are recommended to get a COVID vaccine every 12 months and are eligible every six months.

Check your status and eligibility using this booster eligibility tool and you can access your vaccine history here.

A new review of more than 4,300 studies found full vaccination before a SARS-CoV-2 infection could reduce the risk of long COVID by 27% relative to no vaccination for the general adult population.

With ongoing circulation of COVID, hybrid immunity from natural infection supplemented with booster vaccination can help prevent large-scale COVID waves.

Meru Sheel, Associate Professor and Epidemiologist, Infectious Diseases, Immunisation and Emergencies (IDIE) Group, Sydney School of Public Health, University of Sydney

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Obesity is linked to many common diseases, such as type 2 diabetes, heart disease, fatty liver disease and knee osteoarthritis.

Obesity is currently defined using a person’s body mass index, or BMI. This is calculated as weight (in kilograms) divided by the square of height (in metres). In people of European descent, the BMI for obesity is 30 kg/m² and over.

But the risk to health and wellbeing is not determined by weight – and therefore BMI – alone. We’ve been part of a global collaboration that has spent the past two years discussing how this should change. Today we publish how we think obesity should be defined and why.

As we outline in The Lancet, having a larger body shouldn’t mean you’re diagnosed with “clinical obesity”. Such a diagnosis should depend on the level and location of body fat – and whether there are associated health problems.

What’s wrong with BMI?

The risk of ill health depends on the relative percentage of fat, bone and muscle making up a person’s body weight, as well as where the fat is distributed.

Athletes with a relatively high muscle mass, for example, may have a higher BMI. Even when that athlete has a BMI over 30 kg/m², their higher weight is due to excess muscle rather than excess fatty tissue.

People who carry their excess fatty tissue around their waist are at greatest risk of the health problems associated with obesity.

Fat stored deep in the abdomen and around the internal organs can release damaging molecules into the blood. These can then cause problems in other parts of the body.

But BMI alone does not tell us whether a person has health problems related to excess body fat. People with excess body fat don’t always have a BMI over 30, meaning they are not investigated for health problems associated with excess body fat. This might occur in a very tall person or in someone who tends to store body fat in the abdomen but who is of a “healthy” weight.

On the other hand, others who aren’t athletes but have excess fat may have a high BMI but no associated health problems.

BMI is therefore an imperfect tool to help us diagnose obesity.

What is the new definition?

The goal of the Lancet Diabetes & Endocrinology Commission on the Definition and Diagnosis of Clinical Obesity was to develop an approach to this definition and diagnosis. The commission, established in 2022 and led from King’s College London, has brought together 56 experts on aspects of obesity, including people with lived experience.

The commission’s definition and new diagnostic criteria shifts the focus from BMI alone. It incorporates other measurements, such as waist circumference, to confirm an excess or unhealthy distribution of body fat.

We define two categories of obesity based on objective signs and symptoms of poor health due to excess body fat.

1. Clinical obesity

A person with clinical obesity has signs and symptoms of ongoing organ dysfunction and/or difficulty with day-to-day activities of daily living (such as bathing, going to the toilet or dressing).

There are 18 diagnostic criteria for clinical obesity in adults and 13 in children and adolescents. These include:

• breathlessness caused by the effect of obesity on the lungs
• obesity-induced heart failure
• raised blood pressure
• fatty liver disease
• abnormalities in bones and joints that limit movement in children.

2. Pre-clinical obesity

A person with pre-clinical obesity has high levels of body fat that are not causing any illness.

People with pre-clinical obesity do not have any evidence of reduced tissue or organ function due to obesity and can complete day-to-day activities unhindered.

However, people with pre-clinical obesity are generally at higher risk of developing diseases such as heart disease, some cancers and type 2 diabetes.

What does this mean for obesity treatment?

Clinical obesity is a disease requiring access to effective health care.

For those with clinical obesity, the focus of health care should be on improving the health problems caused by obesity. People should be offered evidence-based treatment options after discussion with their health-care practitioner.

Treatment will include management of obesity-associated complications and may include specific obesity treatment aiming at decreasing fat mass, such as:

• support for behaviour change around diet, physical activity, sleep and screen use
• obesity-management medications to reduce appetite, lower weight and improve health outcomes such as blood glucose (sugar) and blood pressure
• metabolic bariatric surgery to treat obesity or reduce weight-related health complications.

Should pre-clinical obesity be treated?

For those with pre-clinical obesity, health care should be about risk-reduction and prevention of health problems related to obesity.

This may require health counselling, including support for health behaviour change, and monitoring over time.

Depending on the person’s individual risk – such as a family history of disease, level of body fat and changes over time – they may opt for one of the obesity treatments above.

Distinguishing people who don’t have illness from those who already have ongoing illness will enable personalised approaches to obesity prevention, management and treatment with more appropriate and cost-effective allocation of resources.

What happens next?

These new criteria for the diagnosis of clinical obesity will need to be adopted into national and international clinical practice guidelines and a range of obesity strategies.

Once adopted, training health professionals and health service managers, and educating the general public, will be vital.

Reframing the narrative of obesity may help eradicate misconceptions that contribute to stigma, including making false assumptions about the health status of people in larger bodies. A better understanding of the biology and health effects of obesity should also mean people in larger bodies are not blamed for their condition.

People with obesity or who have larger bodies should expect personalised, evidence-based assessments and advice, free of stigma and blame.

Louise Baur, Professor, Discipline of Child and Adolescent Health, University of Sydney; John B. Dixon, Adjunct Professor, Iverson Health Innovation Research Institute, Swinburne University of Technology; Priya Sumithran, Head of the Obesity and Metabolic Medicine Group in the Department of Surgery, School of Translational Medicine, Monash University, and Wendy A. Brown, Professor and Chair, Monash University Department of Surgery, School of Translational Medicine, Alfred Health, Monash University

This article is republished from The Conversation under a Creative Commons license. Read the original article.