Also called: Swine flu
Important: This page is general information, not medical advice. It does not recommend or prescribe any treatment. Always consult your doctor or pharmacist before starting, stopping or changing any medicine.
About H1N1 Flu (Swine Flu)
Swine flu is an infection caused by a virus. It's named for a virus that pigs can get. People do not normally get swine flu, but human infections can and do happen. In 2009 a strain of swine flu called H1N1 infected many people around the world.
The virus is contagious and can spread from human to human. Symptoms of swine flu in people are similar to the symptoms of regular human flu and include fever, cough, sore throat, body aches, headache, chills and fatigue.
There are antiviral medicines you can take to prevent or treat swine flu. There is a vaccine available to protect against swine flu. You can help prevent the spread of germs that cause respiratory illnesses like influenza by:
- Covering your nose and mouth with a tissue when you cough or sneeze. Throw the tissue in the trash after you use it.
- Washing your hands often with soap and water, especially after you cough or sneeze. You can also use alcohol-based hand cleaners.
- Avoiding touching your eyes, nose or mouth. Germs spread this way.
- Trying to avoid close contact with sick people.
- Staying home from work or school if you are sick.
Centers for Disease Control and Prevention
It sits within Infections and Lungs and Breathing.
When to speak to someone. Reading about a topic cannot tell you whether it applies to you. Speak to a doctor or pharmacist if symptoms are severe, sudden, getting worse, or simply not going away — and seek emergency care immediately for chest pain, breathing difficulty, sudden weakness or confusion, or a serious allergic reaction.
Research on H1N1 Flu (Swine Flu)
168 studies areregistered for this condition on ClinicalTrials.gov, the U.S. National Library of Medicine's public registry. A selection is below — the links go straight to the registry entry, not to a summary of ours.
What a registered study does and does not mean. Registration means a study exists and has been declared publicly. It says nothing about whether the treatment being tested works, is safe, or is available to you. Many studies find no benefit — that is what research is for. Never seek out an experimental treatment on the strength of a registry entry alone.
Research currently under way
- BPL-1357 Against H1N1 Influenza Virus ChallengeNational Institute of Allergy and Infectious Diseases (NIAID)
Research already completed
- Cellular and Molecular Characterization of the Immune Response in Healthy NIH Employees atBaseline, and After Immunization With the H1N1 or Seasonal Influenza VaccinesNational Heart, Lung, and Blood Institute (NHLBI)
- Serum and Bronchoalveolar Inflammatory Parameters in Patients With Severe Adult Respiratory Distress SyndromeCentre Hospitalier Universitaire, Amiens
- "COhort Study on A/H1N1 FLU During PREGnancy"Institut National de la Santé Et de la Recherche Médicale, France
- Cohort Study Evaluating the Clinical Effectiveness, Safety and Immunogenicity to the Pandemic Influenza VaccinationAssistance Publique - Hôpitaux de Paris
- Long-term Outcome and Lung Capacity in Survivors of ARDS Due to Influenza A (H1N1) v2009 The RESPIFLU StudyInstitut National de la Santé Et de la Recherche Médicale, France
- Study of SAB-176 in Healthy Adult ParticipantsSAb Biotherapeutics, Inc.
Study data from ClinicalTrials.gov, a service of the U.S. National Library of Medicine. Retrieved 2026-07-30. Registry entries are supplied by study sponsors and investigators; ClinicalTrials.gov does not verify their scientific validity. PocketsInfo is not affiliated with, and not endorsed by, the NLM or the NIH.
Where to read more
Rather than paraphrase, we point you to the primary sources. Every link below is to a government health agency, a national institute or a recognised medical body — grouped by what you are trying to find out.
Start Here
- About Swine/Variant FluCenters for Disease Control and Prevention
Prevention and Risk Factors
- Influenza (Flu) Vaccine (Inactivated or Recombinant): What You Need to KnowCenters for Disease Control and Prevention
Related Issues
- Vaccinations and Flu Shots for People with CancerAmerican Cancer Society
Statistics and Research
- Weekly U.S. Influenza Surveillance ReportCenters for Disease Control and Prevention
Clinical Trials
- ClinicalTrials.gov: Influenza, HumanNational Institutes of Health
Medical subject headings
Clinicians and researchers index this subject under Influenza A Virus, H1N1 Subtype, Influenza, Human. These are the terms to use when searching medical literature.
This page is built from the MedlinePlus health topic record for H1N1 Flu (Swine Flu), a service of the U.S. National Library of Medicine (NLM), National Institutes of Health. Information is from MedlinePlus.gov. PocketsInfo is not affiliated with, and is not endorsed by, the NLM or the NIH. Retrieved 30 July 2026.