Related Experiment Videos
Prevalence of neutralizing antibodies against a candidate rotavirus vaccine in adults
Insights
An urgent need for a rotavirus vaccine exists due to child mortality. Preliminary studies in adults found women had higher antibody levels than men, suggesting male volunteers may be better for vaccine trials.
Area of Science:
- * Virology and Vaccinology
- * Pediatric Infectious Diseases
Background:
- * Rotavirus infections cause significant morbidity and mortality in children globally, particularly in developing countries.
- * A bovine-derived rotavirus vaccine candidate (RIT 4237) shows promise for cross-protection against human rotavirus strains.
- * Pre-licensure studies in adult volunteers are crucial to assess vaccine attenuation and immunogenicity.
Purpose of the Study:
- * To evaluate the antibody profile of healthy adults against the RIT 4237 rotavirus vaccine candidate.
- * To determine if sex influences pre-existing antibody levels relevant to vaccine immunogenicity.
- * To compare the efficacy of neutralization and ELISA assays in measuring antibody responses.
Main Methods:
- * Serum samples from 87 healthy adults (ages 25-40) collected between January and June 1982 were analyzed.
- * Antibodies against RIT 4237 were quantified using both neutralization assays and enzyme-linked immunosorbent assays (ELISA).
- * Statistical analysis compared antibody titers between sexes and assessed correlations between assay methods.
Main Results:
- * Women exhibited significantly higher neutralizing antibody titers against RIT 4237 compared to men (approximately 7 times more frequent).
- * No seasonal variation in antibody levels was observed in male volunteers during winter and spring.
- * A good correlation (75%) was found between neutralization and ELISA antibody measurements, though discrepancies occurred in 22% of sera.
Conclusions:
- * Screening adult volunteers using neutralization assays is recommended before rotavirus vaccine administration.
- * Male volunteers may be preferable for initial vaccine trials due to a higher likelihood of lower pre-existing antibody levels.
- * Discrepancies between neutralization and ELISA suggest careful consideration of assay choice for immunogenicity assessment.
Abstract:
Because of the morbidity and mortality from infection with rotaviruses in children under 2 years, in many parts of the world but especially in developing countries, an urgent need for a vaccine has been recognized. At present, a vaccine candidate of bovine origin, the RIT 4237 strain vaccine developed from a strain received from Mebus et al., is available. This strain has been shown to induce cross protection by challenge of colostrum deprived piglets with human rotavirus strains. Before testing its protective effect in children, preliminary studies in adult volunteers are required to evaluate its degree attenuation and immunogenicity. With regard to the latter we have studied the antibody profile of 87 healthy adults, ages 25 to 40 years, from whom blood samples were taken between January and June 1982. Antibodies versus RIT 4237 were measured both by neutralization and ELISA techniques. Analysis of the results revealed a significant difference in antibody levels according to sex, since high neutralizing antibody titers (greater than 1:320) were observed about 7 times more frequently in women than in men. Furthermore, no seasonal variation in the level and the distribution of serum antibody titers was found when comparing blood specimens taken from male volunteers in winter and spring. As far as antibody levels obtained by neutralization and ELISA assays is concerned, a good correlations was noted in 75% of cases. However, in 22 out of 87 sera high levels of neutralizing antibodies were found in association with low ELISA antibody titers or vice versa. These results suggest that screening of adult volunteers should be performed by means of a neutralization assay prior to administration of a candidate vaccine. However, in the absence of such preliminary testing, male volunteers should be chosen since there is a higher probability of low pre-existing antibody levels among such subjects.