Early US Flu Season Is Türkiye HR's Cue to Plan Winter Absences

What the early-season signals say, and where they come from

If you run HR or a shift-based operation in Türkiye, the first question is whether this autumn's early-flu headlines apply to you. They come from the United States. In California, Monterey County officials reported 9% flu test positivity in October, against about 1% at the same point in the previous two seasons, a level the county usually reaches only after Thanksgiving. They urged everyone aged six months and older to get vaccinated as soon as possible, and officials in Los Angeles said the season started months early and in an unexpected part of the country.

Even in the US the picture is mixed. National activity was still generally low but had been rising since early September, with Western states leading. The European signal is from last season, not this one: an ECDC risk assessment cited by Biruni Laboratory found that 2025/26 cases in Europe started unusually early, driven mainly by the H3N2 subclade K strain.

For Türkiye, nothing published so far points to an early start this season. The normal pattern is the baseline: Klimik, citing national sentinel surveillance, says flu starts each October and peaks in December, and is also common in April and May. So treat the US reports as an early warning, not a forecast. Planning October and November as if the wave could come sooner is a cheap precaution; expecting it is not something the data supports.

Forecasting sick-leave peaks from your own data

Public surveillance tells you the direction. Your own attendance history tells you the size. Pull at least two previous winters of absence data by week, team and shift, and look for where illness absences rose first and where they clustered. Whether customer-facing teams rose before others, or thinly staffed night shifts felt single absences harder, is specific to your company and only your records can answer it.

Use the clinical timeline to set the shape of the forecast. According to the WHO fact sheet), symptoms begin one to four days after infection and usually last about a week, so linked cases on one team tend to surface over several days rather than all at once. Plan for absences arriving unevenly by team, not as a smooth line across the company.

A forecast does not need to be sophisticated to be useful. Here is a hypothetical example, not drawn from any source: a night shift has 6 people and needs at least 5 to run. Your last two Decembers show about 0.5 illness absences per week on that shift in the first two weeks and about 1.5 in the third, and one person already has annual leave approved for week three. Weeks one and two leave roughly 5.5 people on shift, which holds, but week three leaves 6 minus 1 minus 1.5, or about 3.5, well under the minimum of 5.

That single week is the point of the exercise. A simple sheet that sets expected weekly absence per team against the minimum headcount each shift needs will show which weeks and shifts break first. That short list is where your contingency effort should go.

• Weekly illness absences per team for the last two winters
• Minimum safe headcount per shift and per role
• Roles held by only one or two qualified people
• Annual leave already approved for October to January
• Busy business periods that overlap with the usual December peak

Does a workplace flu shot programme pay off?

The evidence is reasonably supportive, with caveats worth stating. A CDC employer toolkit puts the direct cost of flu to US businesses at about $10.4 billion for adult hospitalisations and outpatient visits, and recommends a workplace vaccination clinic offered at no or low cost to employees. An economic analysis from the employer's perspective found workplace vaccination saved about €10 per vaccinated employee per year on average between 2011 and 2018, noting that up to 10% of unvaccinated adults catch seasonal flu each year. The return varied from year to year, so do not promise your finance team a fixed figure.

Much of the absenteeism evidence comes from hospitals. A multi-institutional study found mandatory vaccination for healthcare workers raised vaccination rates by up to 30% and cut absenteeism in critical periods by about 6%, with vaccinated staff showing 30% less absenteeism. In an Italian healthcare trust, unvaccinated workers lost 2.47 work days per 100 person-days versus 1.92 for vaccinated workers. A hospital ward is not a call centre or a factory floor, so read these as directional.

Türkiye's Health Ministry says protection starts two weeks after the shot, names October and November as the preferred months, and says protection lasts about six to eight months. Klimik recommends that people in risk groups start by mid-October at the latest. Put together, an October clinic is the sensible target: it covers the usual December peak and gives some margin if the season turns out earlier. Make it easy to attend during working hours and keep it voluntary unless your sector's rules say otherwise.

What last season's strain mismatch does and does not tell you

The start of the 2025/26 season in England was dominated by H3N2 subclade K, which reacted less well to the vaccine strains in lab tests. Even so, early vaccine effectiveness against flu-related emergency visits and hospital admissions was 72 to 75% in under-18s and 32 to 39% in adults, within typical ranges despite the lab mismatch.

Those figures belong to last season. This season's dominant strain and how well the vaccine matches it are not yet known, so do not quote the 2025/26 adult figure to staff as if it applies now. The ECDC point about possibly low population immunity to H3N2, reported by Biruni Laboratory, was also about 2025/26.

The practical lesson holds either way. Vaccination reduces serious illness, but vaccinated adults can still fall sick. A shot programme lowers the peak; it does not remove the need for a coverage plan.

Presenteeism and the limits of remote work

Absence shows up in your reports. People working while infectious do not, and a systematic review found that infectious illness presenteeism is common and spreads disease. The review cites a Canada Life survey in which 82% of UK workers said they had become ill because a colleague came to work unwell.

Why people come in sick at your company is worth checking rather than assuming. Plausible reasons include worry about lost pay for short illnesses, not wanting to leave a thin team short, or a culture where pushing through gets quiet praise. A short anonymous question in your next pulse survey will tell you more than guesswork. Whatever the reasons, supervisors should say before the season that someone with flu symptoms goes home, then act consistently.

Remote work helps only some roles. A finance analyst with mild symptoms can work from home without infecting anyone; a forklift operator or a nurse cannot. Be honest in the policy about which roles have a remote option, and do not let working from home become the expectation for someone who is too ill to work. A remote day is a working day. A sick day is not.

• List which roles can work remotely when mildly unwell and which cannot
• Tell supervisors that sending symptomatic staff home is expected
• Record remote days and sick days as separate categories
• Ask staff anonymously what makes them come in when unwell

Keeping shifts covered when absences cluster

The hard days are not the average days. They are the mornings when several people from the same small team are out at once. Build coverage around those clusters, which is why the list of single-person roles from your forecast matters more than the headline absence rate.

Cross-training is the slowest lever and the most valuable. If only one person on the night shift can run a specific machine or approve a specific transaction, fix that in October rather than December. A few paired shifts now can let a second person handle the basics when the first is out.

Some decisions are uncomfortable but better made early. In operations that cannot run understaffed, it can be reasonable to limit annual leave approvals around the usual December peak and to agree a short list of people willing to take extra shifts on clear overtime terms. Announce this before the season, not on the morning you need cover.

• Set a minimum staffing level per shift and an escalation rule when it is breached
• Agree an on-call or flexible pool and its terms before the peak
• Cross-train every role held by one or two people
• Decide in advance which non-essential tasks pause when coverage drops
• Give managers one view of who is in, who is out and who is available

Sick leave reports (rapor) and payroll in Türkiye

Under Article 18 of Law No. 5510, SGK pays the temporary incapacity benefit (geçici iş göremezlik ödeneği) from the third day of a report onward, and employers have no legal obligation to pay the first two days. For illness, no benefit is paid on reports of two days or less; occupational disease and work accidents are treated differently.

The process depends on paperwork moving on time. The employee must hand the report to the employer, who then notifies SGK. According to the same source, no benefit is paid if fewer than 90 days of contributions were paid before the report date. When several reports land in the same week, a late hand-over or notification delays the employee's benefit and creates reconciliation work for payroll.

Whether to pay the first two days anyway is a policy choice. My judgement, not a sourced finding, is that it may influence whether people come in sick rather than lose two days of pay; check this in your own data before deciding. Whatever you choose, write it down, apply it consistently and make sure payroll and line managers read it the same way. This is general information, not legal advice; check edge cases with your payroll adviser.

Clean leave records make next winter easier

Bad records cost you twice: once in payroll errors during the season, and again next year when you try to forecast from data you cannot trust. Mixed categories do the most damage. A report day logged as annual leave, a remote day logged as sick, or someone sent home mid-shift with no record at all distorts both pay and your absence history.

Keep categories distinct and capture dates exactly as they appear on the report. Record mid-shift departures, because those partial days can be an early sign of a cluster forming on a team. A time and attendance system that links clock-ins, leave types and payroll cuts down manual reconciliation, but HR has to define the categories and rules first.

After the peak, run a short review. Which teams were hit first, which shifts nearly failed, how many people used the vaccination clinic, and were pay rules applied as written? Then keep the plan ready for spring, since Klimik notes flu is also common in April and May.

• Separate categories: illness report, unreported sick day, annual leave, remote day, sent home mid-shift
• Log report start and end dates exactly as issued
• Track when each report was received and when SGK was notified
• Review the season's data by team and shift once the peak passes