HPV Vaccine: only about 30% of young women who start the series complete it

Two articles, each reporting on a different study, found that uptake of subsequent doses of HPV vaccine, after the first, was poor.  Neither entertained the possibility that side effects might have something to do with this.  Maybe side effects had nothing to do with it.  But since vaccine effectiveness depends on 3 repeated doses, it makes little sense to start the 3-inoculation course and stop midstream.  Here and here the studies are discussed.