"With ardent anti-vaccine activist Robert F. Kennedy Jr. in the country's top health position, use of a long-approved vaccine against measles, mumps, rubella, and varicella/chickenpox (MMRV) as well as flu shots that include the preservative thimerosal will now be reevaluated, putting their future availability and use in question. The development seemingly continues to vindicate health experts' worst fears that, as health secretary, Kennedy would attack and dismantle the federal government's scientifically rigorous, evidence-based vaccine recommendations."