Clinical Trial: Long-term Follow-up of Measles Antibodies

Study Status: Completed
Recruit Status: Completed
Study Type: Interventional

Official Title: Long-term Follow-up of Protective Measles Antibodies in the Two-dose Study of Standard-titre Measles Vaccine in Guinea-Bissau

Brief Summary: Few data exist on long-term persistence of measles antibodies after vaccination of West African infants. The data that do exist indicate that the antibody titres decline very rapidly. Our data would be the first to describe the persistence of measles antibodies after two doses of measles vaccine, and the study would allow us to identify unprotected children and offer them revaccination. Since persistence of measles antibodies is of crucial importance to measles control, the study will contribute significantly to the existing knowledge and might have important implications for future eradication programmes.

Detailed Summary:

Objective To determine persistence of measles antibodies among children who received either one or two doses of Edmonston-Zagreb (EZ) or Schwarz (SW) measles vaccine.

Background The World Health Organization has targeted measles for eradication by the year 2010, and although measles incidence has fallen drastically in many parts of the world, several factors could hinder the eradication goal.

First, there is no indication of improved measles immunisation coverage world wide, vaccination coverage fell in all regions of the world from 1997 to 1998, except in the Western Pacific, so the general measles immunisation coverage came down to 72%. Very high vaccination coverage of ≥ 95% is needed to interrupt transmission of the highly contagious measles virus.

Primary and secondary vaccine failure constitute another significant problem to measles control, and the HIV pandemic contributes to increased vaccine failure, and permits transmission of measles virus despite high rates of immunisation coverage.

Sub-clinical measles has been found to contribute to measles immunity by boosting of the antibody level, and with less circulation of wild measles virus secondary vaccine failure may represent a special problem in terms of waning immunity, a problem which is probably more pronounced among those vaccinated early, but there are still few data relevant to this problem.

Thus, although effective measles vaccines are available, there is still a need to find the optimal way of immunising in different epidemiological settings. In areas with high measles transmission early two-dose measles vaccination schedules have been recommended for prevention of measles in the age group below the nor
Sponsor: Bandim Health Project

Current Primary Outcome: Measles antibody level

Original Primary Outcome: Same as current

Current Secondary Outcome:

Original Secondary Outcome:

Information By: Bandim Health Project

Dates:
Date Received: September 9, 2005
Date Started: March 2002
Date Completion:
Last Updated: September 21, 2011
Last Verified: September 2006