Nevertheless, most H3N2 isolates cannot be antigenically typed for complementing to the QIV . In an exploratory analysis, we assessed QIV efficacy according to influenza A influenza and subtype B lineage. The QIV was most reliable against moderate-to-serious influenza A . Only two instances of influenza B caused by Yamagata lineage viruses were observed, both in the control group. Efficacy against influenza of any severity appeared to be lower among children 3 to 4 4 years than among children 5 to 8 years of age in the per-process cohort .Currently, there is no approved vaccine to safeguard people against Epstein-Barr virus. Lee said some cases of mononucleosis associated with Epstein-Barr are mild, about one in 10 instances are very significant, and also have prolonged symptoms sometimes. Typically, this infection occurs in adolescents and adults – – generally the most healthy segment of the population, said Lee, who works in the Infectious Diseases Program at Winthrop-University Hospital in Mineola, N.Y. Addititionally there is the fatigue which Epstein-Barr virus is notorious for – – that can be severe and prolonged, and may take a month or even more to resolve, he said.