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Recently, the domestic flu has been high, and many people have been infected, including many children. For those who have been infected, we must pay attention to the reasonable and standardized use of oseltamivir, a topic that we discussed in detail in our article yesterday. For those who are not infected, the most important thing is vaccination, questions about vaccination, such as one shot or two? How long is the vaccine protective? There is also how to choose the vaccine specifically, and whether it needs to be vaccinated now, we will discuss it specifically today.
Text | Friends Health
Audit | Wang Xi
This article mainly includes:
1. What are the types of influenza vaccines on the market in China?
2. How long is the vaccine protection period and when is the best injection protection?
3. How to choose between triple and quadrivalent?
4. It was already fought at the end of last year, do you still need to fight this year, and how?
5. Can I get a flu vaccine for egg allergies?
6. Can I get it at the same time as other vaccines?
7. Do I still need to get the Hib vaccine if I get the flu vaccine?
What are the types of influenza vaccines on the market in China?
The influenza vaccines approved for marketing in mainland China include trivalent inactivated vaccines, quadrivalent inactivated vaccines and trivalent live attenuated vaccines.
Quadrivalent inactivated vaccines are all split vaccines, and most brands of trivalent inactivated vaccines are split vaccines, including a subunit vaccine. The subunit vaccine is a high-purity influenza vaccine prepared on the basis of influenza split vaccine using new lysis process and purification technology, with fewer side effects.
How long is the vaccine protection period and when is the best injection protection?
Many people ask this question, and the concern behind it is that they are afraid that if they fight early, the protective effect is gone, they are late, and they are worried that they will not be able to prevent it.
Usually 2-4 weeks after the flu vaccine, protective levels of antibodies are produced. The immunity obtained after influenza vaccination will decay over time, and the degree of attenuation is related to factors such as human age and physical condition, vaccine antigen, etc., and evidence from clinical trials suggests that the protective effect of inactivated influenza vaccine against antigen-like strains can be maintained for 6-8 months.
Serum antibody levels are significantly reduced one year after vaccination, but the duration of protection can be longer in some strains. It is recommended that as long as the current year's influenza vaccine is available, it can be vaccinated as soon as possible, and try to complete the vaccination before the local influenza epidemic season, especially for high-risk groups such as pregnant women
In addition, because young children (under 9 years of age) should receive 2 doses of influenza vaccine for the first time (≥ 4 weeks apart) to obtain maximum protection. Remind everyone to keep an eye on the time.
At present, the flu is circulating, if you are a high-risk group (less than 2 years old, more than 65 years old, have underlying medical conditions, pregnant women, etc.), it is recommended to go to the vaccination early.
How to choose between triple and quad prices?
Due to the large number of vaccines on the market, many people face difficulties in choosing. Which one is better and more convenient.
The so-called trivalent and quadrivalent refers to the number of flu strains that can be covered, and theoretically the quadrivalent is one more virus strain than the trivalent, that is, it can cover one more.
But the success of the flu vaccine selection ultimately depends on two things, one is the local vaccine supply, and the other is the type of influenza strain circulating in the region.
First of all, let me see the types of influenza vaccines recommended for different age groups.
Here is also a detailed introduction to the specific strains covered by this year's quadrivalent and trivalent vaccines.
It can be seen that the quadrivalent vaccine covers one more subtype of influenza B than the trivalent vaccine, and of course, the price of the quadrivalent vaccine is also more expensive.
Trivalent nasal spray vaccine, also trivalent live attenuated vaccine, is a freeze-dried nasal spray vaccine approved by mainland China in 2020, and has a better immune response than adults in infants and school-age children, and has good immunogenicity.
The trivalent nasal spray vaccine covers the same strains of the virus as the trivalent vaccine, but it is contraindicated in the following people:
Those who are immunocompromised due to any reason such as drug use, HIV infection, etc.;
Children and adolescents treated with long-term drugs containing aspirin or salicylic acid;
Children aged 2-4 years with asthma;
Pregnant woman;
People with a history of Guillain-Barre syndrome (GBS);
Those who have used antiviral drugs such as oseltamivir and zanamivir 48 hours before vaccination, or those who have used peramivir 5 days before vaccination, or those who have used baloxavir 17 days before vaccination.
Trivalent nasal spray vaccine (Source: Internet)
By the way, due to the new quadrivalent vaccine for infants under 3 years old this year, these parents may also face the same entanglement of choosing trivalent or quadrivalent, and you can also refer to the above information.
Quadrivalent vaccine for infants and young children aged 6-35 months (Source: Internet)
According to the guideline recommendations: for people who can receive different types or manufacturers of vaccine products, recipients can voluntarily choose to receive any influenza vaccine, and there is no priority recommendation.
It was already fought at the end of last year, do you still need to fight this year, how?
There are indeed many people who care about this issue, so it is worth talking to you. We mainly refer to the 2022-2023 influenza vaccination guidelines published in China at the end of 2022.
First of all, we need to clarify two questions:
age
I got a few injections last year
The situation is different, and the answer is not the same.
First of all, let's look at the 2021 guide recommendations, of course, if you are afraid of trouble, the 2021 guide does not need to be read, directly look at the 2022 update section below.
Source: Technical Guidelines for Influenza Vaccination in China (2021-2022)
Guidelines for 2022 recommend:
Domestic guidelines have changed. According to different ages and selected vaccine varieties, the following protocols are proposed:
Children aged 6 months to 8 years, influenza vaccination:
Have not received a flu vaccine before: it is recommended to get 2 shots (≥ 4 weeks apart);
1 dose or more of influenza vaccine received in the previous year or before: 1 dose is recommended.
Children aged 36 months to 8 years, nasal spray influenza vaccine:
Regardless of whether you have received the flu vaccine or not, only 1 dose is given.
Children 9 years and older and adults:
Only 1 dose is required.
Source: Technical Guidelines for Influenza Vaccination in China (2022-2023)
Separately, it is worth mentioning that this year's updated recommendations are consistent with the May 2022 World Health Organization (WHO) position paper on influenza and influenza vaccines.
The WHO position paper states:
Children aged 6 months to 8 years who have never received the influenza vaccine before should receive 2 doses at least 4 weeks apart.
People who have previously received at least 1 dose should subsequently receive 1 dose per year, and children and adolescents aged 9 years and older, as well as healthy adults, should also receive one dose per year.
The 2021 China guidelines are closer to the latest recommendations of the American Academy of Pediatrics (AAP), that is, children aged 6 months to 8 years are recommended to receive 2 doses if they have received 1 dose of influenza vaccine in the previous year or before; If you have received 2 or more doses of influenza vaccine before, 1 dose is recommended.
Source: AAP Recommendations for Prevention and Control of Childhood Influenza (2021-2022) (Note: The 2022-2023 version of the AAP recommendations is expected to be released in September-October this year)
You can refer to the above international and domestic recommendations, and combine local policies to choose the appropriate plan.
Can you get a flu shot with egg allergies?
The Centers for Disease Control and Prevention's Advisory Committee on Immunization Practices (ACIP) has been recommending flu vaccination for people allergic to eggs since 2016. Therefore, egg allergy is not recommended as a contraindication to influenza vaccination.
Those who are allergic to any of the ingredients contained in the vaccine (including excipients, formaldehyde, lysates and antibiotics) or have a history of severe allergies to any kind of influenza vaccination are prohibited from vaccination.
Can influenza vaccination be given at the same time as chickenpox, mumps, Japanese encephalitis, ACYW flow brain vaccine, and HPV vaccine? Or do you have to take a break apart?
OK. The guidelines mention that trivalent inactivated influenza vaccine can be given at the same time as other inactivated vaccines and live attenuated vaccines, but attention needs to be paid to vaccination at different sites. Chickenpox and mumps vaccines are live attenuated vaccines, Japanese encephalitis vaccine includes live attenuated vaccine and inactivated vaccine, HPV vaccine and ACYW brain vaccine also do not contain live pathogens.
The WHO and CDC also recommend in their technical guidelines for influenza vaccine vaccination that inactivated influenza vaccines can be given at the same time or sequentially as other inactivated vaccines and live attenuated vaccines, while attenuated influenza vaccines require a certain interval before other attenuated vaccines can be administered.
Do I still need to get the Hib vaccine if I get the flu vaccine?
The reason why some people raise this question may be that they do not understand the difference between "influenzae" and "Haemophilus influenzae". Although the name has the word "flu" in it, it is actually a thousand miles away.
The flu virus is a virus, while Haemophilus influenzae (Hib) is a bacterium, although they can both cause fever, cough and other similar symptoms. The flu vaccine and the Hib vaccine target different pathogens. So, taking the quadrivalent flu vaccine and getting the Hib vaccine are two different things.
Of course, in the end, it is still necessary to remind that vaccines can reduce the chance of infection with influenza viruses and reduce the incidence of severe influenza, but no vaccine can provide 100% protection, do not feel that as long as you are vaccinated, everything will be fine, and it is still important to take daily protective measures.
In addition, if the family is unfortunately infected with the flu, remember to use oseltamivir reasonably, this is the article we posted yesterday, you can refer to: the flu is coming, do you want to prepare oseltamivir?
Article first published on 2022-08-27
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Friendly reminder: popular science knowledge is for reference only and cannot replace the doctor's diagnosis and treatment opinion. If you have medical needs, you can consult a doctor online.
Resources:
1) Technical Guidelines for Influenza Vaccination in China (2022-2023)
2) J-P Amorij, A Huckriede, J Wilschut, et al. Development of stable influenza vaccine powder formulations: challenges and possibilities. Pharm Res. 2008 Jun;25(6):1256-73. doi: 10.1007/s11095-008-9559-6.
3) Technical Guidelines for Influenza Vaccination in China (2021-2022)
4) Vaccines against influenza: WHO position paper – May 2022
5) Recommendations for Prevention and Control of Influenza in Children, 2021-2022. Pediatrics. 2021 Oct;148(4):e2021053745. doi: 10.1542/peds.2021-053745.
6) https://www.aap.org/en/pages/2019-novel-coronavirus-covid-19-infections/help-for-pediatricians/preparing-for-flu-season/