ABSTRACT
Background. Novavax COVID-19 Vaccine, Adjuvanted (5 mug recombinant spike protein/50 mug Matrix-MTM adjuvant;NVX-CoV2373) has received regulatory authorizations for use in adults >= 18 years globally. Methods. Participants from PREVENT-19 (NCT04611802), a phase 3, randomized, observer-blinded, placebo-controlled trial that evaluated the efficacy, safety, and immunogenicity of a primary series of 2 doses of NVX-CoV2373 given 21 days apart, in adults >= 18 years in the United States and Mexico, were eligible to receive a booster dose at least 6 months after the initial vaccination series. Short-term safety and immunogenicity of the booster dose was assessed in an ad hoc analysis of 298 participants. Results. There was an incremental increase compared to the initial vaccination series in local and systemic reactogenicity, which was transient and mostly mild-to-moderate in intensity. Most unsolicited adverse events were also mild-to-moderate in severity;there were no deaths or treatment-related SAEs and 2/298 booster recipients in this analysis reported unrelated SAEs. Neutralizing, anti-S IgG, and hACE2 receptor binding inhibiting antibodies against the ancestral (Wuhan) strain 28 days after booster were higher than those 14 days after primary vaccination (Table). Overall, humoral responses were high regardless of interval between priming and booster vaccination, but a longer interval yielded stronger responses. Higher immune responses against the Omicron BA.1, BA.2, and BA.5 variants were also observed after the booster dose than after the primary series in a subset of 14-18 participants tested. Overall, humoral responses were high and broad regardless of age after any vaccination, but higher responses were observed in adults < 65 years after initial and booster vaccinations. A booster dose induced more robust antibody responses compared with the primary series in adults >= 65 years. Conclusion. A single booster dose of NVX-CoV2373 demonstrated a satisfactory safety profile, and high levels of neutralizing, anti-S IgG, and hACE2 inhibition antibody responses against the SARS-CoV-2 prototype Wuhan as well as against the Omicron variant including recently emerged sub-variants. (Table Presented).
ABSTRACT
Background. Long-acting injectable antiretroviral therapy (LAI) is an exciting alternative to daily oral ART. Less frequent dosing afforded by LAI may be especially pertinent for persons who inject drugs (PWID), who experience more HIV-related mortality largely driven by inadequate ART adherence. We used the Consolidated Framework on Implementation Research (CFIR) to characterize determinants of LAI implementation, focusing on use among PWID, in Hanoi, Vietnam. Methods. We conducted in-depth interviews with HIV-infected PWID, ART providers, and policymakers using purposive sampling, recruiting respondents with diverse ART experience from public HIV/ART clinics and national regulatory agencies. Participants were briefed regarding LAI ART, including administration, effectiveness, side effects, and dosing frequency.Datawere coded and analyzed using thematic analysis. Results. We interviewed 19 PWID, 14 providers, and five policymakers (February-November, 2021). We identified recurrent themes in CFIR domains. Intervention(s): All informants were excited about LAI, citing convenience and discrete dosing as major facilitators. Surprisingly, provider concerns, including more frequent clinic visits and injection reactions, were rarely voiced by PWID who described monthly injections as similar to current visit frequency and cited 'high pain tolerance.' Outer: Providers and policymakers were eager to offer patients ART choice but were divided as to if LAI distribution should proceed with sub-population prioritization. Inner: Providers described personnel and clinic logistic concerns but were confident these could be addressed. Individual: Providers were motivated and confident in their ability to deliver LAI. Process: Transitions to new ART and provision of COVID-19 vaccines were frequently invoked by providers and policymakers as interventions informing LAI implementation. Figure Determinants of LAI ART implementation in Vietnam using the domains of the Consolidated Framework on Implementation Research Conclusion. Using CFIR, we identified multiple determinants of LAI implementation in Vietnam. Stakeholders agreed that LAI was feasible and acceptable. Medication tolerance and efficacy concerns highlight the importance of patient and provider education. Areas where stakeholders diverge should be considered in designing LAI implementation strategies.