https://www.cochranelibrary.com/cdsr/doi/10.1002/14651858.CD001321.pub6/full

Conclusions

Cranberry products may help to prevent UTIs which cause symptoms in women with frequent UTIs, in children with UTIs and in people who have undergone an intervention involving the bladder. However, further assessment is required in well‐designed and prospectively registered RCTs to clarify further who with UTIs would benefit from cranberry products.

Are There Other Ways to Avoid Urinary Tract Infections?

If you can’t count on getting a benefit from cranberry pills, you might want another way to avoid repeat UTIs. Sometimes doctors prescribe antibiotics to prevent as well as treat urinary tract infections. On thUrinarye other hand, if they prescribe antibiotics for people without infections, they are not exercising good stewardship of these crucial drugs.

Some readers report that a dietary supplement containing D-mannose helps protect against urinary tract infections. A pilot study published in the European Review of Medical and Pharmacological Sciences (July, 2016) found that D-mannose helped for both the prevention and treatment of urinary tract infections.

I have used these supplements for years. If one has a fever or is shivering and really feels bad then antibiotics may have to be added.