How bad is the new COVID strain hitting London right now?

Back in early 2025, London saw a sharp uptick in respiratory illnesses that didn’t quite match the old COVID patterns. By mid-October, the UK Health Security Agency confirmed a new variant-XBB.1.16, nicknamed "Arcturus"-was spreading fast. It wasn’t the deadly monster some feared, but it wasn’t harmless either. For most people, it felt like a bad cold that wouldn’t quit. For others, especially the elderly and those with chronic conditions, it was a serious wake-up call.

What makes this new strain different?

XBB.1.16 is a descendant of the Omicron family, but it’s got a few key mutations that let it slip past immunity better than its predecessors. It doesn’t cause more severe disease on average, but it spreads faster. Data from Public Health England shows it’s about 30% more transmissible than the BA.2.86 variant that dominated earlier in 2024. That means more people get infected, even if fewer end up in the hospital.

The symptoms? They’re familiar but more stubborn. People are reporting sore throats that last two weeks, intense fatigue that lingers for days, and a dry cough that won’t go away even after the fever drops. Unlike earlier strains, loss of taste and smell is rare now. Instead, many describe a deep chest tightness-like wearing a too-tight sweater-and mild brain fog that makes focusing at work impossible.

Who’s most at risk?

It’s not the healthy 20-somethings. They’re getting sick, sure, but most bounce back in five to seven days. The real concern is older adults, especially those over 70, and people with diabetes, heart disease, or weakened immune systems. In London’s hospitals, the number of patients over 65 admitted with respiratory complications jumped 42% between September and October. That’s not a spike from zero-it’s a big climb from a baseline that was already high.

Children under five are also seeing more cases than before. While most recover at home, emergency rooms in South London and East London have reported a 25% increase in pediatric visits for croup and bronchiolitis linked to this variant. Parents are being told to watch for rapid breathing, wheezing, or refusal to drink fluids.

Are vaccines still working?

Yes-but not perfectly. The 2024-2025 booster, which targets XBB.1.5 and its close cousins, still cuts the risk of hospitalization by about 60% in people over 65. For younger adults, it reduces severe illness by 45%. That’s not 100%, but it’s enough to make a difference. The UK’s NHS has already rolled out the new booster to priority groups: care home residents, pregnant women, and anyone with a compromised immune system. Walk-in clinics are open across London, and appointments are still easy to book.

Here’s the catch: immunity from past infections fades faster now. If you had COVID in 2022 or even early 2024, your protection against XBB.1.16 is weak. A recent Imperial College study found that people who got infected two years ago had only 18% protection against reinfection with this variant. That’s why health officials are pushing boosters again-even if you’ve had it before.

What’s the hospital situation?

Hospitals aren’t overwhelmed like in 2020 or 2021. But they’re stretched. ICU beds are at 83% capacity in London’s biggest trusts-King’s College, St Thomas’, and UCLH. That’s not crisis level, but it’s enough to delay non-emergency surgeries and stretch staff thin. Emergency departments are seeing more respiratory cases than in any October since 2019.

What’s changed is the response. Hospitals now have rapid PCR tests that give results in under 20 minutes. They’re using antiviral drugs like Paxlovid more aggressively, especially for high-risk patients within the first 48 hours of symptoms. That’s cut hospital stays by nearly a third compared to last year.

Should you still wear a mask?

If you’re healthy and young, it’s your call. But if you’re over 60, live with someone who is, or work in a care home or hospital, wearing a high-quality FFP2 mask in crowded indoor spaces is still smart. The data shows masks reduce transmission by up to 70% in enclosed spaces like buses, trains, and supermarkets.

London Underground has seen a 35% increase in mask usage since early October, mostly among older commuters. The city hasn’t mandated masks, but many workplaces have quietly reinstated mask policies. If you’re unsure, ask your employer. Most are being reasonable.

What should you do if you feel sick?

Don’t rush to the ER. Start with a home test. If it’s positive, stay home for at least five days. Use paracetamol for fever, drink fluids, and rest. If you’re in a high-risk group, call your GP or NHS 111 within 24 hours. You might qualify for antiviral treatment.

Watch for warning signs: trouble breathing, chest pain, confusion, or lips turning blue. Those mean go to A&E immediately. Most people don’t need them-but if you do, don’t wait.

How long will this last?

Experts think this wave will peak in late November and fade by mid-December. The variant doesn’t seem to be mutating rapidly right now, which is good news. If no new variant emerges, cases should drop sharply after the holiday season, as people spend more time outdoors and schools return from break.

But the lesson isn’t about panic. It’s about preparedness. COVID isn’t gone. It’s just quieter now. And it still finds the vulnerable.

What’s the bottom line?

This new strain isn’t the end of the world. But it’s not nothing either. For most, it’s a week of feeling lousy. For some, it’s a hospital stay. The tools to protect yourself are still there: vaccines, masks, testing, and knowing when to call for help. Don’t ignore it. Don’t overreact. Just act smart.