It is the flu season.
Recently, the reporter found that topics related to flu vaccines.
It has attracted wide attention on various social platforms.
Many netizens have reported themselves.
I still get the flu after getting the flu vaccine", questioning whether the flu vaccine is good or not;
However, some netizens said that this year's vaccine was not "off target" and was still useful.
This year's flu vaccine.
What exactly is the match with the actual circulating strains?
Is it necessary to get a flu shot?
The reporter interviewed a number of experts and visited offline medical institutions to find answers.
How to "bet" on the flu vaccine
First of all, let's popularize science, how the flu vaccine is "bet on the topic".
First of all, influenza viruses are divided into four types: A, B, C, and D, and there are four main subtypes that can transmit from person to person and cause seasonal epidemic diseases, namely A(H1N1), A(H3N2), B(Victoria) lineage, and B(Yamagata lineage).
Every year, the WHO selects influenza viruses in the northern and southern hemispheres as a vane for vaccine companies to produce vaccines. Generally speaking, if the influenza vaccine strain is more accurate, the influenza vaccine strain and the epidemic strain are better matched, and the effect of preventing influenza after vaccination will be better.
So, how is the match this year?
According to the 780th China Influenza Surveillance Weekly Report in the 47th week of 2023, from November 20 to 26, the influenza viruses in southern and northern provinces of China were dominated by the A(H3N2) subtype, followed by the B(Victoria) lineage.
At present, the influenza vaccines used in China are trivalent inactivated influenza vaccine, trivalent live attenuated influenza vaccine and quadrivalent inactivated influenza vaccine. Among them, trivalent influenza vaccine is used to prevent influenza A H1N1, influenza A H3N2 and B Victoria lineage;In addition to the above three influenza viruses, the quadrivalent influenza vaccine also covers the B-Yamagata lineage.
From the monitoring report, it can be seen that the match between the epidemic strain of influenza and the vaccine strain this year is still relatively high. Professor Fu Chuanxi, chairman of the Vaccinology Education Committee of the China Vaccine Industry Association and deputy dean of the School of Public Health of Zhejiang University of Traditional Chinese Medicine, believes that compared with last winter, the main circulating influenza A (H3N2) subtype virus and influenza B virus have not changed, and they are also consistent with the main branches circulating in most parts of the world. "So this year's flu vaccine is not 'betting on the wrong question'. Regardless of whether you have received a trivalent vaccine or a quadrivalent vaccine, there is a certain degree of protection. Fu Chuanxi said.
Being vaccinated is not the same as insulating yourself from the flu.
Many people may have the misconception that as long as they are vaccinated, they can be "insulated" from the flu.
According to the Technical Guidelines for Influenza Vaccination in China (2023-2024), inactivated influenza vaccine can prevent 59% of laboratory-confirmed influenza in health**When the vaccine strain and the circulating strain are matched, inactivated influenza vaccine reduces influenza-like case visits by 42%. "So it's not that you don't have to get the flu if you get the flu shot, but that the risk of infection is reduced. Fu Chuanxi said.
In fact, the actual protective effect of the vaccine will also be affected by many factors such as the age of the vaccinated, the body's immune status, and the response to the vaccine, and there are obvious differences in the preventive effect of the influenza vaccine against different types and subtypes of influenza.
Since we may not be able to escape the attack of the influenza virus, why do we still need to get the flu vaccine?
The greater value of influenza vaccination over infection prevention is that it can greatly reduce the risk of complications, influenza-related hospitalizations and deaths. Fu Chuanxi told reporters that this is of great significance to children, the elderly and people with low immunity. Research shows that there are about 7There were 10,000 excess deaths from respiratory diseases related to senile illness, accounting for 80% of the deaths from respiratory diseases. "Therefore, for the elderly and immunocompromised people, getting a flu vaccine is 'life-saving'. Fu Chuanxi said. In addition, vaccination can effectively reduce the indirect economic burden caused by influenza.
However, the vaccination rate of influenza vaccine in our country is not high. "Even in more economically developed cities, such as Beijing, Shanghai, and Hangzhou, the vaccination rate is in the single digits. Fu Chuanxi said frankly, "On the one hand, the public's understanding of influenza vaccines and influenza viruses is not in place, and the degree of attention is not enough;On the other hand, the current influenza vaccine is a non-immunization programme vaccine (category 2 vaccine) that requires self-payment and is not a one-time dose, requiring annual vaccination. ”
Zhejiang has noticed such contradictions.
In order to increase the vaccination rate of the elderly, this year, Zhejiang Province will continue to implement the voluntary free influenza vaccination project for the elderly over 70 years old (born before December 31, 1953) with household registration in the province.
Since August, all counties (cities and districts) in Hangzhou have carried out this work one after another. Taking Shangcheng District of Hangzhou as an example, the voluntary free influenza vaccination for the elderly over 70 years old in the district was completed within two weeks, of which 1,716 people were vaccinated in Pengbu Street.
It's better to fight late than not to fight at all!
It's been a little late this year, and hopefully it's not too late. Recently, at the Pengbu Street Community Health Service Center, the reporter met Ms. Chen, who brought her mother to receive the flu vaccine. She said that the whole family has insisted on receiving the flu vaccine for five or six years, "This year there is a bit of a delay, and I was still hesitant to get vaccinated, but I read the news that the risk of infection for the elderly may be greater after December, so I think about it or come to get vaccinated." ”
Bao Haiyan, head of the preventive health department of the Pengbu Sub-district Community Health Service Center, said that after receiving the flu vaccine, it takes about 2 to 4 weeks to produce antibodies with a protective level, and the protective effect can last for about 6 to 8 months.
Although the best time for influenza vaccination is before the end of October, Bao Haiyan believes that "it is better to get vaccinated late than not to get vaccinated", and the current vaccination can still provide good protection. ”
*: Chao News.