An interventional study of EV71 vaccine in Hand, Foot, and Mouth Disease (HFMD) and Enterovirus 71 Infection, sponsored by Sinovac Biotech Co., Ltd. Not yet recruiting at 1 site in Vietnam. Open to participants aged 6 Months to 71 Months, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-09-01.
Sponsored by Sinovac Biotech Co., Ltd · Not applicable, Interventional, and Prevention
The purpose of this study is to evaluate the immunogenicity and safety of an inactivated Enterovirus Type 71 (EV71) vaccine, manufactured by Sinovac, in healthy Vietnamese children aged 6 to 71 months.
Hand, Foot, and Mouth Disease (HFMD) is a common infectious disease in children, and EV71 is a major cause of severe complications and outbreaks in the Asia-Pacific region, including Vietnam. While this vaccine has demonstrated high efficacy and a favorable safety profile in previous clinical trials conducted in China, this study aims to generate specific bridging data for the Vietnamese pediatric population.
This is a single-armed bridging clinical trial that plans to enroll approximately 320 healthy participants. Each participant will receive two doses of the EV71 vaccine administered intramuscularly on a 0 and 30-day schedule. The primary objective is to assess the seroconversion rate of neutralizing antibodies 30 days after the second dose. Safety will be assessed by monitoring the incidence of adverse reactions and serious adverse events (SAEs) throughout the study duration (approximately 2 months).
59 studies on the registry are indexed under Hand, Foot and Mouth Disease; 10 are open to participants now.
This study's planned enrollment of 320 is below the median of 467 across 50 interventional studies indexed under Hand, Foot and Mouth Disease.
Browse Hand, Foot and Mouth Disease studies →Sinovac Biotech Co., Ltd is the lead sponsor of 93 studies on the registry; 19 are open to participants now.
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Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
A condition in which the immune system attacks the body’s own tissues, such as rheumatoid arthritis, lupus, psoriasis, type 1 diabetes or inflammatory bowel disease.
Immunotherapy studies often leave out active autoimmune disease, and some name exceptions, such as thyroid disease on replacement hormone. Check the exceptions this study lists.
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
Investigational drug or device
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Autoimmune disease
A condition in which the immune system attacks the body’s own tissues, such as rheumatoid arthritis, lupus, psoriasis, type 1 diabetes or inflammatory bowel disease.
Immunotherapy studies often leave out active autoimmune disease, and some name exceptions, such as thyroid disease on replacement hormone. Check the exceptions this study lists.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Immunosuppression
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
HIV
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
All participants will receive two intramuscular doses of the inactivated Enterovirus Type 71 (EV71) vaccine (0.5 mL per dose) on a 0 and 30-day schedule.
Biological: EV71 vaccine
Inactivated Enterovirus Type 71 Vaccine (Vero Cell), 0.5 mL per dose. Each dose contains no less than 3.0 EU of inactivated EV71 antigen adsorbed onto aluminum hydroxide. The vaccine is supplied as a milky white suspension in a pre-filled syringe. Participants will receive two intramuscular (IM) injections into the deltoid region of the upper arm, administered on a 0 and 30-day schedule.
Seroconversion rate of Enterovirus Type 71 (EV71) neutralizing antibodies
Seroconversion is defined as: (1) a post-vaccination neutralizing antibody titer of ≥ 1:8 in participants with a pre-vaccination titer of \< 1:8; or (2) at least a four-fold increase in neutralizing antibody titer in participants with a pre-vaccination titer of ≥ 1:8.
Time frame: 30 days after the second dose of vaccination
Seropositive rate of Enterovirus Type 71 (EV71) neutralizing antibodies
The percentage of participants with a neutralizing antibody titer ≥ 1:8 against EV71.
Time frame: 30 days after the second dose of vaccination
GMT of Enterovirus Type 71 (EV71) neutralizing antibodies
The geometric mean of neutralizing antibody titers against EV71.
Time frame: 30 days after the second dose of vaccination
GMFR of Enterovirus Type 71 (EV71) neutralizing antibodies
The geometric mean of the ratio of post-vaccination neutralizing antibody titer to pre-vaccination titer.
Time frame: 30 days after the second dose of vaccination
Incidence of adverse reactions within 30 days
Incidence of adverse reactions within 30 days after each dose vaccination.
Time frame: 30 days after each dose vaccination
Incidence of adverse reactions within 7 days
Incidence of adverse reactions within 7 days after each dose vaccination.
Time frame: 7 days after each dose vaccination
Incidence of SAE
Incidence of serious adverse events (SAE) from the first dose vaccination until 30 days after the second dose vaccination.
Time frame: From the first dose vaccination until 30 days after the second dose vaccination
Plan to share: No
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This study is not yet recruiting, as verified in Aug 2026. You cannot join it, but the record below documents what was studied.
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Studies of the drug tested here: Enterovirus 71 vaccine
Hand, Foot and Mouth Disease →