Follow-Up Study for Measles Maternal Antibodies and Seroconversion after Measles Vaccination

Abstract

Seventy-two children were included in this study which examined measles maternal antibodies in children at the ages of six and nine months. The seroconversion after the first measles vaccination at nine months and revaccination at fifteen months was also evaluated. Results of testing were negative in 33% of the children at six months and in 36% at nine months, indicating continued susceptibility to measles. No significant difference was found in the measles IgG level between six and nine months of age. After the initial vaccination at nine months of age, the seroconversion rate was 85%. After revaccination at fifteen months of age, the children showed a significant increase in their measles IgG levels. The persistence of maternal antibodies is the important cause of the primary vaccine failure observed in infants younger than twelve months [1][2][3]. The optimal age of vaccination remains controversial, and varies in different areas. Seroconversion studies in different populations can be done to determine the earliest age for effective vaccination [4]. Alternatively, a seroprevalence study can be carried out in young infants to determine when maternal antibodies are waning.This study aims to evaluate measles maternal antibodies in children at six and nine months of age and their relationship to the mothers' measles antibody level in order to determine the earliest possible age of vaccination, the seroconversion rate after measles vaccination at the age of nine months, and the effect of revaccination at fifteen months of age. Material and MethodsSeventy-two healthy children, who were referred from primary health care centers and who had normal growth parameters and no history of chronic illness at the age of six months, were included in the study. They were followed through four visits, and at each, a special form was filled out. The first visit was made at six months, and blood samples for measles antibodies were taken from the mother and child. At the second visit, when the infant was nine months old, additional blood samples were taken and the child vaccinated (Schwartz vaccine; Rouvax Biomerieux). The third visit was scheduled when the child was fifteen months old. At that time a third blood sample was taken and an MMR vaccine given (Merck, Sharp, and Dohme). The fourth visit was scheduled two weeks following the MMR vaccination.Twenty-one children had four samples taken. The vaccines were tested for potency using TCID50 (tissue culture infective dose 50%). The end titer in Vero cells was determined using growth and maintenance media (Earl's

Childhood Immunization in the Kingdom of Saudi Arabia

“…On the basis of studies performed in Saudi Arabia on measles vaccine failure 3 and the increased susceptibility of infants less than nine months of age to this infection, 4 measles vaccine timing for the first dose was advanced to age six months provided the immunogenicity-superior Edmonston-Zagreb 5 strain was used. A second dose in the form of combination vaccine with mumps and rubella was recommended at age 12 months to optimize immunity.…”

Measles-specific Neutralizing Antibodies in Rural Mozambique: Seroprevalence and Presence in Breast Milk

“…However this 21% of non-protective is consistent with the generally accepted dogma that 15% of children have primary vaccine failure when vaccinated at nine months of age. 32 The low prevalence of measles PRN titers in infants documented in this study is of public health significance because it suggests that a large number of infants may be highly susceptible to measles infections. However, the role of cell-mediated immunity (CMI), which was not assessed in this study, should be taken into consideration because previous studies have shown early initiation of CMI in the absence of antibodies and in patients with agammaglobulinemia recover from infection and remain protected.…”

A Seroepidemiological Study of Measles: Some Practical Implications for Measles Immunization Program, Kingdom of Saudi Arabia

“…A variable incidence of measles infection among vaccinated population of several countries including the United Kingdom (57%), 19 the USA (25.3%), 20 Canada (66% and 61%), 13 Tunisia (16%), 21 and Hong Kong (23.6%) 10 has been reported. The sporadic outbreak of measles could be explained either by primary vaccination failure attributed to persistent maternal antibodies, impotent vaccine, improper vaccine storage and administration techniques 2,22 or secondary vaccination failure which might be due to other reasons; for example, lack of continuous antigenic stimulation, because of which lifelong immunity is not produced. 5,22,23 Alternatively, the outbreaks of measles could be due to accumulated unvaccinated cases.…”

“…The sporadic outbreak of measles could be explained either by primary vaccination failure attributed to persistent maternal antibodies, impotent vaccine, improper vaccine storage and administration techniques 2,22 or secondary vaccination failure which might be due to other reasons; for example, lack of continuous antigenic stimulation, because of which lifelong immunity is not produced. 5,22,23 Alternatively, the outbreaks of measles could be due to accumulated unvaccinated cases. The finding of IgG seronegativity of randomized vaccinated population under 10 years of age (n=282 out of 2692, 10.48%) further warns that future outbreaks of measles would appear.…”