The weather is getting colder and the flu is coming. Don’t miss the flu vaccine

Recently, many parents have consulted about their children in kindergarten who have developed high fevers. When the children are sick, the parents can't sleep all night. After instructing the parents on medication, the editor also recommends that the parents get the flu vaccine, otherwise the flu may come one after another. Pay attention, the annual influenza season is coming soon, and the severe global epidemic situation of the new crown epidemic will continue this year. From this winter to next spring, there may be a superposition of respiratory infectious diseases such as influenza and new crown pneumonia. And getting the flu vaccine is the most effective way to prevent influenza. However, parents have many doubts about getting the flu vaccine. Here are the answers to these questions about the flu vaccine.

Question 1. I heard that getting the flu vaccine will reduce immunity, and I need to get the flu vaccine every year. Is that true?

A: Flu vaccination will not reduce immunity. Flu vaccination is safe and effective. Vaccination is to allow the body to produce antibodies in advance, enhance immunity, and fight against external viruses. Flu vaccination is required every year because usually 2 to 4 weeks after flu vaccination, antibodies with protective levels can be produced, and the protective effect of antibodies begins to decline after 6 to 8 months. In addition, the virus strains each year may be different from previous years, and the vaccine ingredients will be adjusted each year. Therefore, flu vaccination needs to be taken every year.

Question 2. Can I completely avoid the flu by getting the flu vaccine?

A: It is not necessarily possible to completely avoid influenza. First of all, the effectiveness of the vaccine is not 100%, but studies have shown that the vaccine can significantly reduce the incidence of influenza. Secondly, it takes 2 to 4 weeks after vaccination to produce enough antibodies, and you may still be infected before the antibodies are produced. Finally, influenza vaccination is the most effective means of preventing influenza, which not only reduces the probability of contracting influenza, but also reduces the risk of severe influenza-related complications. Influenza can cause 290,000 to 650,000 respiratory disease-related deaths worldwide each year. In the 2014-2015 season, a study based on concentrated fever outbreaks of influenza in primary and secondary schools in Beijing showed that among students diagnosed with influenza, students who received influenza vaccinations had a significantly lower risk of fever above 38°C than those who did not. In the 2016-2017 epidemic season, the overall protective effect of influenza vaccination for primary and secondary school students in Beijing was 69%. So the benefits of getting a flu vaccine are huge.

Question 3. At what age can one get the flu vaccine?

A: Anyone over 6 months old who has no contraindications to influenza vaccination can get the flu vaccine. It is especially recommended that children aged 6 months to 5 years, family members and caregivers of children under 6 months old, pregnant women, people aged 60 and over, patients with chronic diseases and medical staff should be given priority to get the flu vaccine every year. The United States also recommends that all babies aged 6 months and over get the flu vaccine every year.

During the flu season every year, the influenza prevalence rate among children is about 20-30%. In some high-prevalence seasons, the annual influenza infection rate among children can be as high as about 50%. In addition, children under 5 years old are at a higher risk of developing severe illness after being infected with influenza. Therefore, it is best for all children who can be vaccinated to receive the influenza vaccine.

Question 4. What types of influenza vaccines are there?

Answer: There are three types of influenza vaccines on the market in my country: trivalent inactivated influenza vaccine (IIV3), quadrivalent inactivated influenza vaccine (IIV4) and trivalent live attenuated vaccine (LAIV3). Among them, the trivalent inactivated vaccine can be used for people aged ≥6 months; the quadrivalent inactivated vaccine can prevent one more strain of influenza B virus than the trivalent vaccine, and can be used for people aged ≥36 months; the trivalent live attenuated vaccine is a freeze-dried nasal spray influenza live attenuated vaccine, which is administered by nasal spray without injection and is used for people aged 3 to 17 years. Eligible people can voluntarily receive any influenza vaccine, and there is no priority recommendation. If there is a quadrivalent vaccine in the vaccination area, you can choose the quadrivalent vaccine. If there is only a trivalent vaccine, then get the trivalent vaccine. Don't miss the best vaccination season while waiting.

Question 5. How many times do I need to get the flu vaccine?

Answer: (1) Children aged 6 months to 8 years: Those who are receiving influenza vaccine for the first time or have received less than 2 doses of influenza vaccine in the past should receive 2 doses with an interval of ≥ 4 weeks. For children who have received 2 or more doses of influenza vaccine in previous years, it is recommended to receive 1 dose.

(2) Children 9 years and above and adults: Only one dose is required.

Question 6. When is the best time to get the flu vaccine?

A: Flu vaccines are administered from September to December every year, and it is best to complete the vaccination before the end of October. If only one shot is needed, it is best to do so before the end of October. If two shots are needed, the first shot should be completed by the end of September, and the second shot should be completed by the end of October. If vaccines are in short supply in your area, you can get vaccinated as soon as possible to ensure that the vaccine recipients are immune before the peak influenza season. Those who have not been vaccinated by the end of October can be vaccinated throughout the epidemic season.

Question 7. This time, we are using antiviral drugs for the flu. How long do we have to wait before getting the flu vaccine?

A: You can also get the inactivated influenza vaccine while taking influenza antiviral drugs for prevention and treatment. People who have taken influenza antiviral drugs 48 hours before vaccination are not recommended to get the trivalent influenza live attenuated vaccine. If you are currently using or have recently used any other vaccine or medication, you need to inform the vaccinating doctor before vaccination.

Flu vaccination is the most effective way to prevent influenza and can effectively reduce the incidence of influenza infection in school-age children. Schools are closed places with dense crowds, which are prone to the spread of influenza viruses. Among the influenza outbreaks reported in my country each year, more than 90% occur in schools and childcare institutions. Parents, hurry up and make arrangements for your children.

In daily life, we should also pay attention to the following preventive measures:

(1) Wear a mask because influenza viruses are mainly transmitted through droplets such as sneezing and coughing.

(2) Wash your hands frequently, especially after coughing or sneezing.

(3) Exercise to improve your physical fitness.

(4) Try to avoid crowded and poorly ventilated places.

(5) Ventilate frequently and keep the environment clean

References

[1] Chinese Center for Disease Control and Prevention. Technical Guidelines for Influenza Vaccination in China (2020-2021).

[2] UpToDate: Vaccines for prevention of seasonal influenza in children.

[3] National Health Commission of the People's Republic of China, State Administration of Traditional Chinese Medicine. Diagnosis and treatment plan for influenza (2019 edition)[J]. Chinese Journal of Clinical Infectious Diseases, 2019, 12(6): 451-455.