Two new Covid variants, XFG (known as Stratus) and NB.1.8.1 (known as Nimbus), are now the most common strains in the UK, health officials say. According to experts, the variants do not appear to cause more severe illness than earlier types, though recent genetic changes may make infections easier to contract. People who suspect they have Covid are advised to avoid close contact with vulnerable individuals and, where possible, stay at home. The Royal College of GPs reports that Covid cases are climbing across the UK, especially among the very young and the elderly. People aged 75 and above remain eligible for free NHS vaccinations, which the UK Health Security Agency (UKHSA) says provide good protection against the new variants.