• Measuring the burden of the disease which was caused by the yellow fever is challenging because of the wide range of the clinical severity and non-specific symptoms reported in majority of the infection. This has made diagnosis for yellow fever very difficult for investigators. It was found that the investigators failed to report the yellow fever. The estimate of yellow fever depends on the data from the serological surveys as shown in the study which was conducted on the Nigerian children in question 3. But however there are no evidences that yellow …show more content…
The occurrence of the age related reporting bias is also another issue in the study. Apart from this, the estimated age distribution of travelers from the Geo Sentinel clinics who received the yellow fever vaccine in 1998 was applied for the entire study and it was generalizable to the entire United States. But however in the recent days, the proportion of elderly travelers has increased and this projection has caused the overestimation of the number of older travelers and it will have the chances of underestimating the reporting rate ratio of adverse events in the elderly. The study also did not include the data on the children less than 15 years of age which has resulted in the underestimation of the adverse events reporting rates in other age groups. Another issue is that the analysis and reports of the vaccine adverse event reporting system reports identifies only systemic adverse events caused by hepatitis A vaccination and did not explain that the age specific adverse event caused by yellow fever vaccine, which will reflect the age related response of the individuals to the vaccines in general. Another issue is the lack of the clinical evidence that identified yellow fever vaccine as the cause of