New Covid-19 variant known as XFG, ‘Stratus’ spreading overseas: What Australians must know

A new, highly contagious Covid-19 strain has emerged globally as thousands of Australians prepare to travel overseas. This is what we know.

A new, highly contagious Covid-19 strain has emerged globally as thousands of Australians prepare to travel overseas. Understanding what it is, is crucial for both public health and individual safety. This is what we know about the latest variant, its impact, and how Australians can keep themselves safe.

What is the new Covid-19 variant?

The latest Covid-19 variant is known as XFG (“Stratus”), which is often called a “Frankenstein variant” because it’s a mix-and-match of different virus types, or has many changes. This basically means it’s a new version built from parts of others. Like a puzzle, these changes make XFG unique. These unique features often help it spread more easily, which is why health experts worldwide are keeping a close eye on it. It’s another example of how the virus keeps evolving.

What is a “Frankenstein” Covid variant?

The unsettling term “Frankenstein variant” has entered the public scope again, referring to highly mutated or recombined versions of the Covid-19 virus. It typically describes strains like Omicron and its descendants, including NB.1.8.1 (nicknamed “Nimbus”) and XFG (“Stratus”),or even hybrids such as “Deltacron”. These variants are gaining significant attention due to their rapid global spread, with variants like BA.2.86 (Omicron subvariant).

Where is the new Covid-19 ‘Stratus’ variant spreading?

The ‘Stratus’ variant (XFG) is spreading rapidly across Europe and has a significant presence in Southeast Asia, with India noting a considerable increase and becoming dominant. It was first detected in Canada and also accounts for a notable percentage of samples in the United States. While it continues to transmit sporadically within the UK and has been detected in samples across 38 countries globally by GISAID, current data does not specifically confirm its widespread presence in Australia.

How are these “Frankenstein” variants different from other strains?

“Frankenstein” variants, encompassing Omicron and its sub-lineages like ‘Nimbus’ and ‘Stratus’, are characterised by a substantial number of mutations, particularly within the spike protein vital for cellular entry. Some, like the “Deltacron” variants, are literal hybrids, formed through the recombination of different existing strains - Delta and Omicron - within a single infected individual.

These extensive genetic alterations can enhance transmissibility and potentially enable immune evasion. Early data from the UK indicates that some of these highly mutated variants, such as BA.2.86, demonstrate similar levels of antibody escape compared to other circulating variants, with no evidence suggesting they cause more severe illness.

A nurse loads a syringe with a COVID-19 booster vaccine. Picture: AP

Should I get a Covid-19 jab before travelling?

Remaining up-to-date with your COVID-19 vaccinations, including any recommended booster doses, is widely advised to maintain robust protection against severe disease and hospitalisation, irrespective of travel plans.

While the specific efficacy of vaccines against novel variants is continuously assessed, current formulations are still expected to significantly reduce severe outcomes.

Public health bodies, including the World Health Organisation and the Australian Immunisation Handbook, advocate for vaccination based on individual age, risk factors, and the evolving variant landscape to ensure protection against circulating strains.

For precise travel advisories, always consult official health and travel guidelines pertinent to your destination and origin.

According to the Australian Government’s Health Department data from June 11, 2025, Australia’s COVID-19 vaccine program has administered a total of 74.2 million vaccine doses. Over the past six months, 1.7 million doses were given to adults aged 18 and over. Vaccination uptake as of the latest data, includes 2.2 million Australians aged 75 years and over, 2.5 million aged 65-74, and 15.2 million aged 18-64.

What are the common symptoms associated with these variants?

The symptoms observed with newer COVID-19 variants, including those informally dubbed “Frankenstein” variants, largely mirror those of previous Omicron subvariants. These commonly include upper respiratory symptoms such as fever, cough, sore throat, runny nose, and sneezing. Other frequently reported symptoms involve fatigue, headache, muscle aches, and loss of appetite. While the loss of smell or taste was a more indicative symptom in earlier strains, it appears to be less prevalent in Omicron infections. It is important to remember that symptom presentation can vary widely among individuals.

How transmissible are these “Frankenstein” variants?

Variants labelled as “Frankenstein” are frequently distinguished by their heightened transmissibility. For instance, the Omicron variant demonstrated significantly greater contagiousness compared to Delta. More recent strains like Nimbus and Stratus have also exhibited rapid global dissemination. Their extensive mutations, particularly within the spike protein, can enhance their ability to infect human cells efficiently, thus facilitating their swift spread.

Are current vaccines effective against these new variants?

Existing Covid-19 vaccines have consistently proven effective in preventing severe illness, hospitalisation, and death across a range of variants, including Omicron and its sub-lineages. While breakthrough infections (infections in vaccinated individuals) can occur, maintaining an up-to-date vaccination status offers the best available protection against severe health outcomes. Vaccine manufacturers and public health authorities continuously assess the efficacy of current vaccines against emerging variants and are prepared to develop updated formulations specifically targeting new strains when necessary.

Advice for Australians travelling as variants spread

For Australians planning to travel internationally, comprehensive predation is key to minimising health risks. According to Health Direct, it is crucial to:

- Consult the Smartraveller website for specific destination advice

- Visit a doctor for pre-travel medical advice and to confirm necessary vaccinations.

- Be aware of how to avoid infection, including practicing good personal hygiene and food safety

- Pack well-fitting masks, alcohol-based hand sanitiser, rapid antigen tests, and at least four weeks’ extra supply of regular medications.

- Adhere strictly to local public health regulations, including mask mandates, social distancing protocols, testing requirements, and isolation rules.

- Ensure you are up-to-date with your Covid-19 vaccinations before departure.

Originally published as New Covid-19 variant known as XFG, ‘Stratus’ spreading overseas: What Australians must know