Efter influenzavaccination er der observeret falsk- positive resultater m. h. t. antistoffer mod HIV- 1, Hepatitis C og specielt HTLV- 1, når ELISA- metoden er anvendt.
Following influenza vaccination, false positive results in serology tests using the ELISA method to detect antibodies against HIV-1, Hepatitis C and especially HTLV-1 have been observed.