New health data has prompted the NHS to once again encourage certain groups to get their flu vaccination. Recent figures from NHS England show that cases of winter viruses are climbing again. For example, as per Mirror, hospital admissions due to flu have risen by 9% over the past two weeks, after the previous fortnight had suggested a decline in cases. At the same time, daily numbers of patients admitted with norovirus and Covid have increased compared with the previous week.Despite these rising cases, the NHS confirmed that it has administered over 18.6 million flu vaccines this winter, an increase of more than half a million compared with the same period last year. With the surge in winter viruses putting extra strain on hospitals and ambulance services, the NHS emphasised that thousands of flu vaccination appointments are still available.NHS Issues New Flu Jab AlertPosting on X, the NHS said: "Flu can be serious, especially for older people and those at higher risk. Millions have already been vaccinated this season, and there are still thousands of appointments available."If you're eligible, it’s not too late to get yours." Many people, particularly those in vulnerable groups, may qualify for a free flu vaccine.Who Is Eligible For The Free Flu Jab?According to NHS guidance, there are six main categories of people eligible for a free flu jab. You might qualify if you need additional protection or if someone in your household does.This includes people who:Are pregnantHave certain long-term health conditionsLive in a care homeAre aged 65 or over, or will turn 65 by March 31, 2026Are the main carer for an older or disabled person, or receive a carer's allowanceLive with someone with a weakened immune system (for example, someone undergoing chemotherapy)NHS national medical director Professor Meghana Pandit said: "It’s clear that the worst is far from over for the NHS this winter. Hospitals have seen another rise in admissions from flu and other respiratory viruses last week. The cold weather is also contributing to an increase in vulnerable patients visiting A&E with respiratory issues and more injuries from slips and falls due to icy conditions, so it remains an extremely busy period."How To Get The Flu Vaccine For Free?If you qualify for a free flu jab, there are several ways to access it. As per Mirror, you can call your GP surgery directly to book an appointment, or arrange one at a pharmacy either online or through the NHS app, as long as you are 18 or older.Some pharmacies also offer the NHS vaccine at no cost and accept walk-ins without prior booking. This service isn’t available at every pharmacy, but you can locate the nearest pharmacy offering the complimentary vaccine here.