ERVW-1 and infection: Animals were allocated into three experimental groups based on sex and age1: a sham control group (Sham, n = 12)2, a vaccine group comprised of two Ad26 vector primes and MVA vector boosts at weeks 24 and 36 and weeks 48 and 60 post-infection, respectively, each expressing SIVsmE543gag–pol–env immunogens (Ad26/MVA, n = 12), and3 an Ad26/MVA vaccine group with an SIVsmE543 gp140 protein subunit boost with alum adjuvant with each MVA inoculation (Ad26/MVA + Env, n = 12) (Fig. 1A).