Effect of Meningococcal Conjugate Vaccine on Meningococcal Carriage
meningococcal conjugate vaccine (Menactra)
Meningitis
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Prevention Study
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Summary
The purpose of this study is to determine whether the new meningococcal conjugate vaccine (MCV4) can reduce asymptomatic carriage of meningococcal bacteria, and thus decrease the transmission of these bacteria in the population. The purpose of this study is to determine whether the new meningococcal conjugate vaccine (MCV4) can reduce asymptomatic carriage of meningococcal bacteria, and thus decrease the transmission of these bacteria in the population. Neisseria meningitidis is a leading cause of bacterial meningitis in the United States. A new tetravalent (A, C, Y, W-135) meningococcal conjugate vaccine (\[MCV4\], MenactraTM manufactured by Sanofi Pasteur Inc.) has been approved by Food and Drug Administration (FDA) in January 2005. This vaccine is recommended by ACIP for routine vaccination of young adolescents at the pre-adolescent visit (11-12 years old), adolescents at high school entry (15 years old), and college freshmen living in dormitories. Prevention of asymptomatic nasopharyngeal carriage of meningococci is important to interrupt person-to-person transmission and to induce herd immunity, when lower transmission results in lower disease rates among those people who are not vaccinated. No studies have yet been done to evaluate the impact of this new vaccine on carriage. This is a randomized study designed to evaluate the effect of MCV4 on meningococcal carriage. Several high schools will be randomized into the intervention and control groups. Students in intervention group will receive MCV4 at the beginning of the study, students in the control group will be offered MCV4 after the study completion. Three specimens of throat secretions (similar to swabs for Strep throat) will be collected from the students enrolled in the study: before vaccination of intervention group students (at the start of the school year), 8 weeks post-vaccination, and 9 months post-vaccination (at the end of the school year). Questionnaire administered at the time of swabbing will assess potential risk factors for meningococcal carriage. Meningococcal bacteria isolated from the throat specimens will be serogrouped and molecularly typed. Approximately 2,000 students in each group will be needed for the study. Anticipating 35% refusal rate and 25% loss to follow-up, approximately 4,200 high school students will need to be approached in each group. This study will answer an important question whether those who are vaccinated are protected not only from disease, but also from being asymptomatic carriers of meningococci. If so, those who are vaccinated will not be able to carry and transmit bacteria to unvaccinated individuals. Meningococcal conjugate vaccines may become available in the near future to other age groups, including infants and children. Determining the efficacy of MCV4 against meningococcal carriage will be important for policy decisions regarding vaccination with this and future conjugate vaccines in different age groups.
Protocol
This section provides details of the study plan, including how the study is designed and what the study is measuring.In this clinical study, participants are placed into groups randomly, like flipping a coin. This ensures that the study is fair and unbiased, making the results more reliable. By assigning participants by chance, researchers can better compare treatments without external influences.
Other Ways to Assign Participants
Non-randomized allocation: Participants are assigned based on specific factors, such as their medical condition or a doctor's decision.
None (Single-arm trial): If the study has only one group, all participants receive the same treatment, and no allocation is needed.
Participants are divided into different groups, each receiving a specific treatment at the same time. This helps researchers compare how well different treatments work against each other.
Other Ways to Assign Treatments
Single-group assignment: Everyone gets the same treatment.
Cross-over assignment: Participants switch between treatments during the study.
Factorial assignment: Participants receive different combinations of treatments.
Sequential assignment: Participants receive treatments one after another in a specific order, possibly based on individual responses.
Other assignment: Treatment assignment does not follow a standard or predefined design.
Everyone involved in the study knows which treatment is being given. This is typically used when it's not possible or necessary to hide the treatment details from participants or researchers.
Other Ways to Mask Information
Single-blind: Participants do not know which treatment they are receiving, but researchers do.
Double-blind: Neither participants nor researchers know which treatment is given.
Triple-blind: Participants, researchers, and outcome assessors do not know which treatment is given.
Quadruple-blind: Participants, researchers, outcome assessors, and care providers all do not know which treatment is given.
Eligibility
Researchers look for people who fit a certain description, called eligibility criteria: person's general health condition or prior treatments.Conditions
Criteria
