Summary
mRNA-1273 vaccine efficacy against SARS-CoV-2 Delta wanes over time; however, there are limited data on the impact of durability of immune responses on protection. Here, we immunized rhesus macaques and assessed immune responses over 1 year in blood and upper and lower airways. Serum neutralizing titers to Delta were 280 and 34 reciprocal ID50 at weeks 6 (peak) and 48 (challenge), respectively. Antibody-binding titers also decreased in bronchoalveolar lavage (BAL). Four days after Delta challenge, the virus was unculturable in BAL, and subgenomic RNA declined by ∼3-log10 compared with control animals. In nasal swabs, sgRNA was reduced by 1-log10, and the virus remained culturable. Anamnestic antibodies (590-fold increased titer) but not T cell responses were detected in BAL by day 4 post-challenge. mRNA-1273-mediated protection in the lungs is durable but delayed and potentially dependent on anamnestic antibody responses. Rapid and sustained protection in upper and lower airways may eventually require a boost.
【저자키워드】 COVID-19, SARS-CoV-2, antibody, mRNA vaccine, T cells, B cells, Delta, mucosal immunity, nonhuman primates, anamnestic, 【초록키워드】 Efficacy, immune response, lung, virus, RNA, BAL, Rapid, sgRNA, T cell response, Blood, boost, Neutralizing titer, rhesus macaque, Bronchoalveolar lavage, mRNA-1273 vaccine, lower airways, nasal swabs, responses, immunized, remained, dependent on, sustained, was reduced, declined, anamnestic antibody, lower airway, 【제목키워드】 vaccination, mRNA-1273, protection, lung, rhesus macaque, anamnestic antibody,