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Sustained virologic control of human immunodeficiency virus type 1 (HIV-1) infection after discontinuation of antiretroviral therapy (ART) is a major goal of the HIV-1 cure field. A recent study reported that administration of an antibody against α 4 β 7 induced durable virologic control after ART discontinuation in 100% of rhesus macaques infected with an attenuated strain of simian immunodeficiency virus (SIV) containing a stop codon in nef We performed similar studies in 50 rhesus macaques infected with wild-type, pathogenic SIVmac251. In animals that initiated ART during either acute or chronic infection, anti-α 4 β 7 antibody infusion had no detectable effect on the viral reservoir or viral rebound after ART discontinuation. These data demonstrate that anti-α 4 β 7 antibody administration did not provide therapeutic efficacy in the model of pathogenic SIVmac251 infection of rhesus macaques., (Copyright © 2019 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.)

Zika virus (ZIKV) is responsible for a major ongoing epidemic in the Americas and has been causally associated with fetal microcephaly. The development of a safe and effective ZIKV vaccine is therefore an urgent global health priority. Here we demonstrate that three different vaccine platforms protect against ZIKV challenge in rhesus monkeys. A purified inactivated virus vaccine induced ZIKV-specific neutralizing antibodies and completely protected monkeys against ZIKV strains from both Brazil and Puerto Rico. Purified immunoglobulin from vaccinated monkeys also conferred passive protection in adoptive transfer studies. A plasmid DNA vaccine and a single-shot recombinant rhesus adenovirus serotype 52 vector vaccine, both expressing ZIKV premembrane and envelope, also elicited neutralizing antibodies and completely protected monkeys against ZIKV challenge. These data support the rapid clinical development of ZIKV vaccines for humans., (Copyright © 2016, American Association for the Advancement of Science.)

Preclinical studies of viral vector-based HIV-1 vaccine candidates have previously shown partial protection against neutralization-resistant virus challenges in rhesus monkeys. In this study, we evaluated the protective efficacy of adenovirus serotype 26 (Ad26) vector priming followed by purified envelope (Env) glycoprotein boosting. Rhesus monkeys primed with Ad26 vectors expressing SIVsmE543 Env, Gag, and Pol and boosted with AS01B-adjuvanted SIVmac32H Env gp140 demonstrated complete protection in 50% of vaccinated animals against a series of repeated, heterologous, intrarectal SIVmac251 challenges that infected all controls. Protective efficacy correlated with the functionality of Env-specific antibody responses. Comparable protection was also observed with a similar Ad/Env vaccine against repeated, heterologous, intrarectal SHIV-SF162P3 challenges. These data demonstrate robust protection by Ad/Env vaccines against acquisition of neutralization-resistant virus challenges in rhesus monkeys., (Copyright © 2015, American Association for the Advancement of Science.)

CD4 T cells promote innate and adaptive immune responses, but how vaccine-elicited CD4 T cells contribute to immune protection remains unclear. We evaluated whether induction of virus-specific CD4 T cells by vaccination would protect mice against infection with chronic lymphocytic choriomeningitis virus (LCMV). Immunization with vaccines that selectively induced CD4 T cell responses resulted in catastrophic inflammation and mortality after challenge with a persistent strain of LCMV. Immunopathology required antigen-specific CD4 T cells and was associated with a cytokine storm, generalized inflammation, and multi-organ system failure. Virus-specific CD8 T cells or antibodies abrogated the pathology. These data demonstrate that vaccine-elicited CD4 T cells in the absence of effective antiviral immune responses can trigger lethal immunopathology., (Copyright © 2015, American Association for the Advancement of Science.)