Finland's flu season has reached the epidemic level, says Niina Ikonen, a senior researcher at the National Institute for Health and Welfare (THL).
Health centres around the country report a spike in patients with flu-like symptoms.
By the end of December, there were 834 diagnosed cases of influenza A viral infections and 1,729 cases of influenza B.
Most of those diagnosed have been aged 15 to 64, making up more than 1,200 of the total. Just under 800 patients have been over 65, while nearly 700 have been children under the age of 14.
The situation is now officially considered an epidemic in more than half of the country, but flu incidence remains lower in parts of Eastern Finland, for instance.
However official diagnoses represent only a small fraction of those who actually fall ill – as most wisely stay home. And few of those cases checked at health centres or hospitals are actually confirmed with laboratory tests.
Peak in early February?
Officials say that the peak weeks of the epidemic still lie ahead. Last winter's peak was unusually early, around the turn of the year. This year the epidemic has not spread as quickly yet.
"According to the long-term averages, the peak weeks are often in late January and early February – and surprisingly often during the main school holidays in mid-February," says Ikonen. She says this year's flu season seems to be on track to follow the same pattern.
More than a million vaccinated
According to the THL, flu vaccination coverage is good this season. The agency has distributed nearly 1.6 million vaccination doses. They are handed out to health centres based on national guidelines regarding risk groups, which include people over the age of 65, pregnant women and children aged 6-35 months.
Nearly a million doses have been used so far.
"It appears that the vaccinations have been taken as actively as last year," says Hanna Nohynek, head of Vaccine Programme Development at the National Institute for Health and Welfare (THL).
The THL figures do not include all vaccinations in the private sector, for which there is no reliable data.
"Pharmaceutical companies have delivered nearly 300,000 doses of flu vaccine to the private sector, including private medical centres and pharmacies," says Nohynek.
Unusual flu season
This winter's flu season has begun exceptionally, says Nohynek. Normally the influenza A virus appears first, followed by influenza B in the late winter and early spring.
"This has been a highly atypical epidemic. Now the season has started with the B virus. We don't know yet how it will develop and how the B virus will be around," she tells Yle, noting that viruses are unpredictable.
About one third of diagnosed cases so far have been influenza A type viruses.
At the moment, the Type B/Yamagata flu, which has emerged as the most common strain, is not included in the national seasonal vaccine, but some vaccines available from private clinics may also protect against this B virus.
So should those in risk groups get a second shot from the private sector for better protection during this flu season?
Nohynek says there is no official recommendation about this, but no obstacle to it, either. She says that such an epidemic usually lasts about four months, and that if one is considering an additional jab, it should be done soon.
"The epidemic has already started and the B virus is in circulation. It takes two weeks before the vaccination provides protection," says Nohynek. She adds that in any case, hand hygiene is crucial, especially while travelling.