Prof. Dr. Yong Phuworawan or “M.YongThe head of the center specializes in clinical virology. Department of Pediatrics Faculty of Medicine Chulalongkorn University Facebook post the issue “hand, foot and mouth disease vaccinerevealRisk groupare more young children than older children The younger the age, the more likely it is to be born than the older age.
HFMD hand, foot and mouth disease vaccine
after school There is an outbreak ofHFMDmore clearly grouphand-foot-mouth symptoms Caused by many viruses, including Coxsackie A, such as CA6, CA16 Coxsackie B, Enterovirus-A. and many more
The most severe case with encephalitis is EV-A 71. are more young children than older children The younger the age, the more likely it is to be born. getting older
In this year’s outbreak, most of the CA6 strains show considerable skin symptoms. There are blisters on the roof of the mouth, hands, feet, elbows, knees, around the buttocks, and when healed, some will have marks on the nails.
in the outbreak some years Will be caused by the EV71 strain, as shown in the figure, that had an epidemic in 2017 or 5 years ago, our center has been monitoring hand-foot-mouth disease outbreaks for more than 10 years until now, as shown in the graph. to see each year what is the species for the benefit of care and protection
hand, foot and mouth disease vaccine That being said, in fact, it’s not right to call it. It must be called a vaccine against EV71. Only because cross-species cannot be prevented to prevent CA or CB. Giving this year Won’t prevent hand, foot and mouth this year. Most of them are CA6.
EV71 virus also distinguishes more than 10 substituents, for example strains AB and C B will be B 1 to B 5 C will be C1 -C5.
Vaccine against EV71 is made from strain EV71 substrain C4, but our Thailand outbreak in 2017 was strain EV-71 B5 and before the covid outbreak we found that the EV71 that was found was starting to be C1 strain. And this year, most of the outbreaks detected so far are not EV71, but CA6.
No clinical studies have been conducted. to confirm how effective crossbreeding is. Only in vitro studies have been performed. The mainland China vaccine is made from the C4 strain, the Taiwanese vaccine studied. Made from the B4 strain.
What must be understood is The hand-foot-mouth vaccine EV71 does not protect against Hand-foot-mouth that occurs mostly in Thailand. with strains CA6, CA16, etc. will be specific protection against EV71 and what will need to be studied cross-species protection between EV71 C4 to protect against EV71 B5 or C1 strains found in our home how much It is something that should be planned for further studies. to consider the future use of the vaccine
Vaccine against EV-A-71
It has been mentioned that the vaccine is used only against enterovirus A 71, which is one of the causes of HFMD. And may cause severe encephalitis, myocarditis.
Infection with EV 71 does not affect everyone with encephalitis or myocarditis. It is in young children under 5 years of age, and about 60% of these are found between the ages of 6 months to 2 years, or say that in young children, the chances of the disease are severe. Complications are more common in older children.
Looking back 10 years ago, we would have lost a child. especially young children every year as a unit per year Most of them are young children with complications, encephalitis, myocardial infarction, pulmonary edema. improved by giving IVIg
from the study of immunity Against the EV 71 strain B5 found in Thailand. by our team at the center And published in the international journal “Vaccination” In the long-term follow-up of Thai children up to 4 years, it is clear that newborn babies will have immunity to about 80% of EV71 B5 strains. from mothers who are mostly immune and the immunity will decrease rapidly And almost unmeasurable at the age of 6-7 months and after that Thai children will naturally start to be infected. The immunity to EV71 strain B5 increases with increasing age, as shown in the figure, thus making children from 6 months of age more susceptible to infection and the severity of the disease.
And we conducted an immunogenicity study against EV71 strain B5 in young and old populations in Khon Kaen Province as shown in Fig. This report is published in the international journal “J Biomed Sci” and shows the detection of HFMD. during that period
Therefore, if you want to create a landscape Prevention of infection with EV 71. Needed to be given to young children and to be immune to 6 months of age.
Inactivated Vaccine Studies EV71 C4 China strain is given at 6 months of age and given twice 1 month apart and has been used in China for many years.
part of taiwan The B4 strain was conducted in a phase 3 study in Vietnam with good results from 2 months of age and older.
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