What are the differences between the flu and the common cold?
Influenza is an acute respiratory infectious disease caused by the influenza virus. Influenza viruses are classified into four types: A, B, C and D. Currently, the predominant strain of influenza in China is subtype H3N2 of type A. The prevalent strains each year are one or more subtypes of influenza A (H3N2), Influenza A (H1N1), or type B. It is a normal rule for influenza to have different dominant strains each year.
01 How does the flu spread?
Droplet transmission: When sneezing, coughing or speaking, virus-carrying droplets are produced. After others inhale these droplets, the virus may enter their bodies and spread through indirect contact.
Contact transmission: After touching the mouth, nose, eyes and other parts, the virus may spread to objects through hands, such as placing hands on keyboards, door handles, switches and other places. When others come into contact with these virus-contaminated objects, they are very likely to be infected.
02 How to distinguish influenza from the common cold?
The common cold mainly affects the nose and throat
Pathogen: It can be caused by infections of different types of viruses and is a self-limiting disease.
Symptoms: Concentrated in the nasopharynx, such as nasal congestion, runny nose, sneezing and sore throat. The general symptoms are mild. Generally, there is no fever or only a low fever, and it usually resolves on its own within a week.
It has weak infectivity and rarely causes serious complications.
Influenza is a fierce attack on the “entire body system”
Pathogen: Caused by a specific influenza virus, it is a self-limiting disease.
Symptoms: Acute onset, severe systemic symptoms. The main manifestations are sudden high fever (often reaching 39℃ to 40℃), chills, severe headache, general muscle aches and extreme fatigue.
It is highly contagious and prone to widespread transmission. For high-risk groups such as infants and young children, the elderly, pregnant women and those with chronic underlying diseases, it may cause serious complications such as pneumonia, myocarditis and encephalitis, and even threaten life.
03 How to deal with flu symptoms?
During the illness, pay attention to staying at home and resting, avoid going to public places or having close contact with others until the symptoms basically disappear.
If signs such as persistent high fever, breathing difficulties, and listlessness occur, medical attention should be sought promptly. High-risk groups are advised to seek medical attention as soon as possible after infection.
Patients should keep an appropriate distance from their families. It is recommended that they have separate meals, enhance ventilation, and wash their hands promptly after contact.
The following groups are at high risk of severe influenza and require special protection: infants and young children, pregnant women, the elderly, and people with chronic underlying diseases (such as heart and lung diseases, diabetes, immunosuppression, etc.).
04 How to carry out daily protection?
Wash your hands frequently: Use soap and running water, or use alcohol-based hand sanitizer.
Wearing masks: Wear masks scientifically and properly to prevent respiratory infectious diseases.
Enhance physical fitness: Ensure adequate sleep, maintain a balanced diet, and engage in moderate exercise.
Open Windows for ventilation: Keep the indoor air circulating.
Avoid gatherings: During the high flu season, try to avoid crowded places as much as possible.
Respiratory etiquette: Cover your mouth and nose with a tissue or your elbow when coughing or sneezing.
Institutional prevention and control: Schools, kindergartens and other institutions should strengthen morning and afternoon health checks, disinfection and epidemic monitoring.
It is very important not to wait until you are infected. It is crucial to get the flu vaccine in time
When it comes to the flu vaccine, this “protective weapon”, many people are confused:
The flu has already broken out. Is it still in time to get vaccinated now? “Even after getting vaccinated, one may still get infected. Is the vaccine really effective?” ” “I just got vaccinated last year. Do I need to get vaccinated again this year?” ”
01 Is it still in time to get vaccinated now?
Influenza activity continues to rise. Many people believe that the best vaccination period has passed and it is too late to get vaccinated at this time. However, this is not the case.
Experts say that it takes 2 to 4 weeks for antibodies to develop after getting the flu vaccine. Antibodies can be produced throughout the entire flu season, which can provide a certain level of protection.
02 Can one still get infected after vaccination? Is the flu vaccine effective?
According to the World Health Organization’s estimation, the seasonal prevalence of the influenza virus can lead to an average of about 3 to 5 million severe cases and 290,000 to 650,000 respiratory disease-related deaths worldwide each year.
The influenza vaccine is currently the most economical and effective “weapon” in medicine for preventing influenza. Its core function does not lie in completely avoiding infection, but in significantly reducing the rate of severe cases and mortality.
Experts say that after vaccination, the risk of severe illness and death caused by influenza A (H3N2) will be significantly reduced. For the general population, the risk can be reduced by more than 40%, and the risk reduction ratio is even higher for the elderly and children.
03 If I got the flu vaccine last year, do I need to get it again this year?
The immune protection of the influenza vaccine has a time limit. Antibodies produced after vaccination usually last for 6 to 9 months, and the protective efficacy basically disappears after more than one year.
The World Health Organization predicts the prevalent strains of the New Year based on global surveillance data every year and recommends that the latest vaccines be administered annually to achieve the best protective effect.
On November 3rd, the Chinese Center for Disease Control and Prevention released the “Technical Guidelines for Influenza Vaccination in China (2025-2026)”. The guideline clearly states that compared with the previous year, the components of the H3N2 influenza A virus subtype vaccine have been replaced this year. This means that protection will be more precise.
04 Which groups of people are not eligible for the flu vaccine?
The following two types of people are absolutely forbidden:
People who are allergic to the components of the flu vaccine.
People who have experienced severe allergic reactions after getting the flu vaccine in the past.
Influenza vaccines are divided into two major categories: one is inactivated vaccines, which can completely kill the virus; The second type is attenuated live vaccines, which only reduce the virulence of the virus while retaining its activity. People with weakened immune systems, such as children aged 2 to 4 with asthma, patients with underlying diseases, pregnant women, and users of immunosuppressants, are not recommended to receive live attenuated vaccines, but they can receive inactivated vaccines normally.
05 When should one not get the flu vaccine?
It is not recommended to get the flu vaccine during the acute infection period. You should wait until the symptoms disappear and your body has basically recovered before getting vaccinated.
Some patients with underlying diseases may be physically weak after infection. They need to consult a doctor first, comprehensively assess their own physical condition, and then choose an appropriate vaccination time.
Post time: Dec-12-2025