Open Source Apothecary At Home / Infection and immunity

Influenza and when it is serious

Vaccination and, for high-risk people, antivirals. Elderberry is a modest adjunct and not a treatment for pneumonia.

remedy

Influenza is not a bad cold. It kills people, mainly the very young, the very old, pregnant women, and those with chronic disease, and the two interventions that change outcomes are vaccination and, in high-risk groups, antiviral treatment.

Vaccination reduces infection and, importantly, reduces severe disease and death. It needs to be given before the season and repeated annually because the virus drifts. This is the intervention with the largest effect on outcomes and it is not a supplement.

Antivirals (oseltamivir, baloxavir) reduce illness duration modestly and reduce complications in high-risk groups, and they must be started early — within about 48 hours. They are a clinical decision and the window matters. A person in a high-risk group with influenza symptoms should contact a clinician promptly rather than starting a herbal protocol.

Elderberry has small trials showing reduced duration of influenza-like illness. It is a modest adjunct, generally safe, and it is not a treatment for influenza pneumonia.

Zinc has trials showing reduced cold duration; the evidence for influenza specifically is thin.

Vitamin D — correcting a deficiency reduces respiratory infection; it is not a treatment for influenza.

The red flags are the substance of this page. Influenza becomes dangerous through pneumonia — viral or secondary bacterial — and through decompensation of underlying disease. Breathlessness, chest pain, confusion, a fever that returns after improving, or a person who is deteriorating rather than slowly improving needs urgent assessment. So does influenza in a high-risk person, and in a child who is drowsy, breathing fast, or not drinking.

What helps the illness itself, honestly. Rest, fluids, antipyretics for comfort, and time. Honey for the cough above one year. Not spreading it — stay home while febrile. And do not give aspirin to a child or teenager with influenza, because of Reye's syndrome.

What the studies found

Preparation

The interventions that change outcomes

• Vaccination, annually, before the season
• Antivirals for high-risk groups, started within 48 hours — a clinician's decision
• Stay home while febrile; this is a public health intervention

Symptom management

• Rest and fluids; oral rehydration solution if not eating
• Paracetamol or ibuprofen at the proper dose for fever and aches
• Honey for cough, 1-2 teaspoons, only above 12 months of age
• Saline nasal irrigation for congestion
• Steam for a congested chest

Adjuncts with modest evidence

• Elderberry — standardised syrup or extract; small trials in influenza-like illness
• Zinc lozenges — reduced cold duration; do not use zinc nasal products
• Vitamin D — correct a deficiency

What not to do

• No aspirin in a child or teenager with influenza — Reye's syndrome
• Do not use antibiotics; influenza is viral, and antibiotics are indicated only for a confirmed secondary bacterial infection
• Do not use a herbal protocol in place of an antiviral in a high-risk person

Who is high risk

• Over 65; under 2; pregnant; and anyone with chronic heart, lung, kidney, liver, neurological or metabolic disease, or immunosuppression

Cautions and interactions

• No aspirin in children or teenagers with influenza. Reye's syndrome is rare and often fatal.
• Antivirals must be started early in high-risk groups. A herbal protocol is a delay.
• Elderberry is a modest adjunct and not a treatment for pneumonia.
• Antibiotics do not treat influenza.

When this is not a self-care problem — get help

• Breathlessness, chest pain, confusion, or bluish lips — emergency care.
• A fever that returns after improving, or that persists beyond 5 days — possible secondary bacterial pneumonia; assessment.
• Influenza in a high-risk person (over 65, pregnant, chronic disease, immunosuppressed) — contact a clinician promptly.
• A child who is drowsy, breathing fast or noisily, not drinking, or has few wet nappies — urgent assessment.

Related

• Coughs and colds: honey, zinc, and the honest list
• "Immune support": what the trials actually show
• Fever: what it is for, and when it means something else
• Children: smaller, and different

Sources

1. Vitamin D supplementation to prevent acute respiratory infections: systematic review and meta-analysis of stratified aggregate data. The lancet. Diabetes & endocrinology 2025; doi:10.1002/9781119536604 PubMed 39993397
2. Short-term Dual Therapy or Mono Therapy With Acetaminophen and Ibuprofen for Fever: A Network Meta-Analysis. Pediatrics 2024; doi:10.1542/peds.2023-065390 PubMed 39318339
3. Contribution of Chinese herbal medicine in the treatment of coronavirus disease 2019 (COVID-19): A systematic review and meta-analysis of randomized controlled trials. Phytotherapy research : PTR 2023; doi:10.1002/ptr.7669 PubMed 36382689
4. Vitamin D supplementation to prevent acute respiratory infections: a systematic review and meta-analysis of aggregate data from randomised controlled trials. The lancet. Diabetes & endocrinology 2021; doi:10.1016/S2213-8587(21)00051-6 PubMed 33798465
5. Effect of micronutrient supplements on influenza and other respiratory tract infections among adults: a systematic review and meta-analysis. BMJ global health 2021; doi:10.1101/2020.04.08.20058578 PubMed 33472840