Phase II study on the safety and immunogenicity of single-dose intramuscular or intranasal administration of the AVX/COVID-12 "Patria" recombinant Newcastle disease virus vaccine as a heterologous booster against COVID-19 in Mexico.

Background: The global inequity in the distribution of COVID-19 vaccines underscores the urgent need for innovative and cost-effective vaccine technologies to address access disparities and implement local manufacturing capabilities. This is essential for achieving and sustaining widespread immunity, and for ensuring timely protection of vulnerable populations during future booster campaigns in lower- middle income countries (LMICs).

Methods: To address this need, we conducted a phase II clinical trial to evaluate the safety and immunogenicity of the locally manufactured AVX/COVID-12 "Patria" (AVX) vaccine as a booster dose.