Guide
After the recent high incidence of whooping cough, many parents are asking about the pertussis vaccine, especially the 6-year-old injection, why are there more and more whooping coughs in older children now?
Is it bad to be protective? Do you want to beat your child? Why hasn't there been an outbreak abroad, is it someone else's vaccine?
You may be a little surprised after reading it, for example, after the older children are fully vaccinated, they can't prevent whooping cough.
Let's talk about the specific content today.
Simple and rough version
In mainland China, after being vaccinated with the vaccine containing whooping cough at the age of 1.5, there will be no more, and Hong Kong in the United States is 6 years old, 11 years old, and there are 2 more shots than us.
Because pertussis is currently increasing among adolescents, it is necessary to vaccinate older children against whooping cough.
Older children are protected from pertussis-containing vaccines for 2-3 years after vaccination, and then they are basically not protective. In addition, the acellular pertussis vaccine has lower immunity than the whole cell vaccine in addition to the protection period.
If you want to prevent it, you have to avoid contact with sick people, which is a little more difficult, because both asymptomatic and early stage are contagious, and the most contagious.
If you have the conditions, such as friends in Shenzhen, it is very convenient, then you can go to Hong Kong to get vaccinated, and it is good to evaluate the cost performance yourself.
Table of Contents
- The current pertussis vaccination process in China
- What are the various vaccines in English?
- How to get pertussis vaccine in Laomei and other places?
- Is it useful for older children to get a vaccine that contains whooping cough?
- So how can it be prevented?
- Going to Hong Kong to get a 6-year-old whooping cough vaccine?
- Should we follow the plan of Hong Kong or the United States?
1. The current pertussis vaccination process in China
At present, in our country[1], the requirement is to receive 4 doses of diphtheria, tetanus, tetanus, tetanus, tetanus, tetanus, Then at the age of 6, the diphtheria, tetanus, and tetanus vaccine was given in it, and there was no whooping cough.
If you have not been vaccinated on time, you will need to catch up on vaccination, as follows:
If the child is between 3 months and 5 years old (i.e. before the age of 6) and has not completed the prescribed dose of diphtheria, tetanus, tetanus
If the child is 6 years of age or older, the diphtheria-pertussis vaccine cannot be used, and diphtheria-tetanus-pertussis (DT) vaccine is required for supplementation.
According to national regulations, 3 doses are required, and at least one dose is the diphtheria-pertussis vaccine.
But this region will be different, for example, Beijing is required to be before the age of 18, these needles are not complete, that is, 3, 4, 5 months old, 1.5 years old, 6 years old, all have to be completed, and there is one more shot in the third year of junior high school.
Whatever region you are in, you just listen to that region.
And then no matter where in the country, after the age of 6, there is no vaccination containing whooping cough.
Second, what are the English languages of the various vaccines?
For example, you can see DTaP, DT, Tdap, Td and so many other vaccines, what does this mean?
先看字母的意思，D 是白喉（Diphtheria）的英文首字母，T 是破伤风（Tetanus）的英文首字母，P 是百日咳（Pertussis）的英文首字母。
In this, D is sometimes a big D, sometimes a small D; P is sometimes a large P, sometimes a small P, and P, no matter how big or small, has an A in front of it; T's are all big T's.
"a" stands for "acellular" and refers to the fact that the component of pertussis is not the whole cell, but a part of the pertussis bacillus, such as the toxoid as an antigen that stimulates the body to produce antibodies.
Because the adverse reactions of this cell-free vaccine are smaller, the current pertussis vaccine is basically cellular, that is, ap (like the figure below), if it is intact cellular, the abbreviation is wP.
Then the case of the letter is determined by the amount of the ingredient in the vaccine, if the content is large, it is uppercase, and if the content is low, it is lowercase. Because of the severity of tetanus, it is all sufficient, and it is all with a capital T.
Therefore, DTaP contains more of the three vaccines, which are used by children aged 6 years and younger (under 7 years old), and Tdap has a low level of diphtheria/tetanus, which is used by children over 7 years old or adults.
If pertussis vaccination is contraindicated, DT or Td is used.
How to get the whooping cough vaccine in Sanlao Mei and other places?
Lao Meina, the first 4 doses were the same as ours, and they were vaccinated with DTaP at 2, 4, 6 months of age, and 15-18 months of age[2].
After that, at 4 to 6 years of age, DTaP is also administered.
By age 11 to 12 years, receive Tdap.
Women receive one dose of Tdap at each pregnancy.
The difference here is that the vaccine received at the age of 6 contains whooping cough, and the vaccine containing whooping cough will be given again at the age of 11-12.
Then the vaccination schedule in the UK is 2, 3, 4 months of age, 3 years of age, 4 months of age, and around 14 years of age, a total of 5 doses of pertussis-containing vaccine [3].
In Hong Kong, 2, 4, 6 and 18 months old, 6 years old (Primary 1) and 11 years old (Primary 6) were vaccinated against pertussis[4] and received diphtheria-pertussis-polio vaccine.
The 11-year-old was given diphtheria (reduced dose), tetanus, non-cell pertussis (reduced dose) and polio vaccine (Tdap-IPV).
Is it useful for the four big kids to get the pertussis-containing vaccine?
Pertussis vaccination did significantly reduce the incidence of whooping cough, as shown in the figure below, from 1922 to 2019 [5], the incidence of pertussis in the United States decreased significantly, but it was not eliminated.
Image from Ref. [5]
The DTP in the picture above is a whole-cell pertussis vaccine, which has a good protective effect, but the side effects are slightly greater, such as febrile convulsions/encephalitis, etc., and there are fatal cases.
Therefore, the acellular pertussis vaccine was invented later, which is DTaP and Tdap, which will be less protective, but also have a protective effect, that is, the protection time is too short.
As can be seen from the figure above, after the use of acellular pertussis vaccine, pertussis has recurred and the number of cases has increased, mainly in children under 1 year of age, but there is also a large increase in elementary school students (7-10 years old), as shown in the figure below:
Image from Ref. [5]
Based on the issue of short protection period, so at the current age of 11-12 years, will I get another dose of pertussis vaccine, will it work? Let's move on.
In 2016, there was a study in the United States[6] that evaluated the effect of the vaccine on children over 10 years old who were vaccinated with Tdap, and finally found that in the first year of vaccination, the protective effect of the vaccine was 68.8%, that is, compared with the unvaccinated, the number of cases decreased by 68.8%, which is a good effect.
However, over time, the protection becomes less and less, and after the third year, only 8.9% of cases can be reduced, which is basically no protection, as shown in the figure below:
Image from Ref. [6]
Therefore, after 2-3 years of vaccination, there is basically no protection, and the results of other studies are similar, and the authors conclude that this routine pertussis vaccination cannot prevent whooping cough outbreaks.
5. How to prevent that?
The vaccine will be more or less effective, so it is better to get vaccinated according to the current regulations.
Then, do a good job of prevention, don't go to crowded places, go to indoor playgrounds less, you can have a good prevention, and this is basically the only way.
After infection, the infection is strongest when there are no symptoms or in the early stage, that is, during the catarrhal phase, and it is quite difficult to distinguish and not touch it.
6. Do you want to go to Hong Kong to get a 6-year-old whooping cough vaccine?
In Hong Kong, at the age of 6, the DTaP-IPV (4-pack) vaccine was administered, and at the age of 11, the Tdap-IPV vaccine was given.
Of course, we have to know that after vaccination, the protective effect will be very low after 2-3 years, calculate the cost performance by yourself, and the most important thing is not to contact the patient.
In addition, the vaccine containing pertussis should not be vaccinated too much, more than 6 doses before the age of 7 [7] may cause adverse reactions, but we should be vaccinated at the age of 2, 3, 4 months, 1.5 years old, and then go to Hong Kong to receive the 6-year-old shot, which is not much.
Finally, contact the clinic before you go to determine the interval from the previous pertussis-containing vaccine.
7. Should we follow the plan of Hong Kong or the United States in China?
Although the above evidence says that the vaccine cannot be prevented, it is more or less a means of prevention, and it is more secure to follow the plan of Hong Kong or the United States.
I look forward to taking advantage of this whooping cough outbreak to change the process as soon as possible, and if you can protect it for 2 years, you will be protected for 2 years, after all, after infection, the cough is too uncomfortable.
-Bibliography-
[1].国家免疫规划疫苗儿童免疫程序表.
[2].CDC.Child and Adolescent Immunization Schedule by Age.2024.
[3].NHS.https://www.nhsinform.scot/healthy-living/immunisation/when-to-immunise/.
[4].香港兒童免疫接種計劃.2024.https://www.fhs.gov.hk/tc_chi/main_ser/child_health/child_health_recommend.html
[5].Peter Gilligan.Evaluating Efficacy of Pertussis Vaccines in Children.https://asm.org/articles/2022/october/evaluating-efficacy-of-pertussis-vaccines-in-child
[6].Klein N P, Bartlett J, Fireman B, et al. Waning Tdap Effectiveness in Adolescents[J]. Pediatrics, American Academy of Pediatrics (AAP), 2016, 137(3).
[7].Jan E Drutz.6 周至 6 岁儿童百白破疫苗免疫接种.uptodate.2024.