Chickenpox Vaccine Still Useful for School Children?
Chickenpox Vaccine Still Useful for School Children?. In the past two years, around November each year, the number of school children suffering from chickenpox has increased significantly, and every occurrence has cost a lot of manpower and material resources to deal with, which has seriously affected the normal teaching order of the school.
The sick students are from kindergarten to high school, and most of them have no history of varicella vaccination. For the class where the epidemic has occurred, we recommend that other students get the chickenpox vaccine as soon as possible, but every time teachers and parents have questions: someone in the class already has chickenpox, is it still useful to get chickenpox vaccine now? This question needs to be explained in detail.
1. The epidemic characteristics and harm of chickenpox
Let’s first understand the “primordial culprit” of chickenpox-varicella-zoster virus. This product can not only cause chickenpox, but it can also be latent in the human body. When the immune system is reduced, it will come out again and cause herpes zoster.
In addition to skin herpes, chickenpox can also cause hemorrhagic chickenpox or secondary bacterial infections, pneumonia, encephalitis and other serious complications. The population is generally susceptible, and patients are the only source of infection. 90% of susceptible children become ill after contact. It is easy to cause outbreaks in kindergartens, primary and secondary schools and other collective units. It is an important cause of public health emergencies in schools and kindergartens. one of the reasons.
The disease is highly contagious, mainly spread through respiratory droplets and direct contact, and can also be spread through contact with contaminated equipment. The epidemic is more difficult to control. The onset can occur throughout the year, with winter and spring being the highest. School doctors start to get nervous every October. The rash is contagious from 1-2 days before the onset of the disease until the rash is completely crusted. After the illness, it needs to be isolated at home. This time can be as little as a few days to about half a month, which is a great psychological shock to students and parents. According to the requirement, if there are 5 cases of chickenpox in a class within a week, classes need to be suspended, and that affects not one or two students.
2. The protective effect of varicella vaccine
Varicella vaccine is the most effective way to prevent chickenpox, which can effectively reduce the incidence of chickenpox inoculated children. Domestic studies have shown that the efficacy of a dose of domestic varicella vaccine is 81%-93%. The Mete analysis of epidemiological protection effect shows that the overall protection rate is 73%.
The WHO study shows that the average effectiveness of a dose of varicella vaccine to prevent moderate or severe varicella is 95%, and the effectiveness of preventing severe varicella is 100%. Breakthrough cases may occur in people who receive one dose of the vaccine, and two doses can basically avoid the occurrence of breakthrough cases.
Although varicella vaccine has a good immune effect, it is a self-funded vaccine in most areas of some countries, and the vaccination rate is not high, so that there is no protective antibody after the child enters nursery school and school, and there is a risk of illness.
3. Do you need emergency immunity after chickenpox occurs?
After the outbreak of chickenpox in school, because children have been studying together for a long time, the risk of infection is high. Some children may have been exposed to the chickenpox virus or have been in the incubation period, and it will take some time for the vaccine to produce protective antibodies. We understand the parents’ questions very well, and we can’t let the child get a shot without the protection effect.
When an outbreak of chickenpox occurs, vaccination of susceptible persons within 3 days after exposure can prevent more than 90% of rashes, and vaccination within 5 days after exposure can prevent 70% of rashes and reduce the severity of the disease by 100%. It can not only protect the unimmunized population, but also shorten the duration of the outbreak.
The United States once vaccinated 26 contacts in 21 families within 3 days after contact. As a result, none of the children became ill. Suzhou City requires schools, kindergartens and other collective units that have a chickenpox outbreak or a public health emergency to carry out emergency immunization for close contacts as soon as possible based on risk assessment. Therefore, after an outbreak of chickenpox in schools, it is not only necessary to vaccinate chickenpox, but it is also recommended as soon as possible.
Of course, emergency immunization also has certain conditions. Suzhou City stipulates that the cumulative vaccination of the previous varicella vaccine is less than 2 doses and the history of undiagnosed varicella disease. Although some people may be in the incubation period of chickenpox, vaccination can reduce the severity of the disease and still has positive significance. In December 2019, on the premise of parents’ knowledge and willingness, we once vaccinated a class with chickenpox epidemic, which produced a very good protective effect.
Regardless of whether there is a chickenpox epidemic in the school, it is recommended that all students who are not contraindicated get 1-2 doses of chickenpox vaccine as soon as possible.