In Greece, post-pandemic monitoring data from the Primary Health Care Morbidity Surveillance Network suggest that the seasonal wave typically starts between November 10 and December 10, with its peak around the beginning of the new year.

“Based on the epidemiological data recorded in the Southern Hemisphere, this year in Greece we expect a longer flu season accompanied by more severe illness,” Deputy Health Minister Eirini Agapidaki told the Athens–Macedonian News Agency (AMNA).

So far, due in part to the extended warm weather, cases have been recorded in the community, but the numbers remain relatively low. Agapidaki explains that the flu season usually lasts from October to the end of March.
“However, this year we estimate it may extend even until the end of April. This has already prompted heightened vigilance among relevant authorities and makes flu vaccination imperative — especially for people with vulnerable immune systems: those with chronic illnesses, the elderly, pregnant women, infants, and young children.”

Which flu strain appears likely to dominate

“Epidemiological data from the Southern Hemisphere, which precedes the Northern Hemisphere in seasonal flu activity, offer an indication of what Europe should expect this winter,” says Christos Chatzichristodoulou, president of the National Public Health Organization (EODY).

In Japan and Australia, the season began earlier than usual and was marked by high community transmission, again exceeding the five-year average. The wave was driven mainly by the A/H1N1pdm strain, with lower levels of B/Victoria. The A/H3N2 strain appeared at low levels throughout the season, except in South Africa where it circulated widely during the winter months.

Early data from the UK show dominance of the antigenically drifted “K” clade of the A(H3N2) subtype, potentially signaling increased transmissibility. Greece’s National Flu Reference Centers in the North and South are monitoring for the presence of this clade in the country.

Vaccination: the strongest shield of protection

The most effective way to prevent flu infection is timely vaccination. When administered correctly and early, the flu shot reduces transmission and protects against severe complications. Because the body requires about two weeks to build an immune response, vaccination should ideally occur before cases surge.

Last year, 2.4 million people in Greece were vaccinated against the flu. This year, by November 11, roughly 1 million have received the shot.

With vaccination progress at a critical point and winter approaching — bringing a rise in respiratory infections — Deputy Minister Agapidaki stresses the importance of getting vaccinated.

“It is vital not to neglect our annual flu vaccination,” she says. “The standard flu shot is easy, free of charge, and does not require a doctor’s prescription. It is available to all citizens, insured or uninsured, through public health facilities and pharmacies. Every vaccination is recorded in the National Vaccination Registry, ensuring proper monitoring and safeguarding public health.”

Agapidaki notes that the flu vaccine is updated every year to match the strain expected to dominate, calling vaccination “the most effective shield and prevention strategy — one that saves lives and reduces pressure on health services.”

She also emphasizes the role of doctors and health professionals in informing the public about the protection vaccines offer, significantly lowering the risk of hospitalization and death from complications.

“Prevention is always the best treatment, and flu vaccination is the simplest and most effective step. Let’s treat it not as a chore, but as an act of responsibility and social solidarity — a small but meaningful preventive action today that can avert serious consequences tomorrow,” Agapidaki concludes.

Who should get vaccinated

Mandatory high-priority groups:

• Adults 60+
• Infants and children 6 months to 5 years
• Children over 5 and adults with at least one of the following risk factors or chronic illnesses:
  • Chronic respiratory diseases (e.g., asthma, COPD)
  • Serious cardiac disease
  • Immunosuppression (genetic or acquired)
  • Organ or bone marrow transplantation
  • Sickle cell anemia and other hemoglobinopathies
  • Diabetes or other chronic metabolic diseases
  • Chronic kidney disease
  • Chronic liver disease
  • Neurological or neuromuscular disorders
  • Down syndrome
• Pregnant women (any stage of pregnancy), postpartum women, and breastfeeding mothers
• Individuals with morbid obesity (BMI >40) and children with BMI above the 95th percentile
• Children on long-term aspirin therapy
• People in close contact with infants under 6 months, or with individuals who have underlying conditions increasing flu-related risk
• Closed or institutional populations: boarding students, military/police academies, special schools, institutional care settings
• Workers in healthcare facilities and refugee/migrant accommodation centers
• Homeless individuals
• Veterinarians, poultry and swine farmers, animal handlers — including mink breeders — slaughterhouse workers, and anyone in systematic contact with birds or pigs

Flu and COVID-19 will circulate simultaneously

Health authorities note that this winter the flu virus will circulate alongside SARS-CoV-2, the virus that causes COVID-19.
Vaccination against both viruses remains the most important preventive measure, especially for high-risk groups.

Additional protective measures include frequent handwashing, avoiding crowded indoor spaces, proper ventilation, and seeking medical care promptly if symptoms appear.