Antibody dynamics in Japanese paediatric patients with influenza A infection treated with neuraminidase inhibitors in a randomised trial

Abstract

Neuraminidase inhibitors (NAIs) complement influenza virus infection management by helping to clear virus, alleviate symptoms, and reduce transmission. In a previous randomised study, we examined the effect of 4 NAIs on virus clearance and influenza symptoms in Japanese paediatric patients. In this second analysis, we examined the effects of NAI treatment on antibody responses and virus clearance, and the relationships between antibody responses and patients’ infection histories (previous infection; asymptomatic infection via household members of same virus type/subtype; vaccination), and between infection histories and viral kinetics. Haemagglutination inhibition (HI) antibody responses produced HI titres ≥40 by Day 14 of NAI treatment, in parallel with virus clearance (trend test P = 0.001). Comparing patients with and without influenza infection histories (directly or asymptomatic infection via household members) showed that infection history had a marked positive effect on HI antibody responses in patients vaccinated before the current influenza season (before enrolment). Current virus clearance was significantly faster in patients previously infected with the same virus type/subtype than in those not previously infected, and clearance pattern depended on the NAI. Assessment of anti-influenza effects of antiviral drugs and vaccines should consider virus and antibody dynamics in response to vaccination and natural infection histories.

Effect of peramivir on respiratory symptom improvement in patients with influenza virus infection and pre‐existing chronic respiratory disease: Findings of a randomized, open‐label study

“…Collectively, these findings suggest that peramivir 300 mg single dose is effective and well tolerated in high‐risk patients with chronic respiratory diseases and is able to reduce the duration of influenza symptoms compared with oseltamivir. These results also support previous evidence that, owing to the rapid increase in plasma concentration after administration, 15 peramivir reduces virus levels more quickly than oseltamivir 8 and independently of immune status 6 …”

“…3 Antiviral treatment with a neuraminidase inhibitor (NAI) can bring clinical benefits, including clearing virus, alleviating symptoms, reducing transmission, 5 and potentially improving survival. 1,6 NAI efficacy has been explored predominantly in patients with uncomplicated seasonal influenza. [7][8][9][10][11] Among these agents, intravenous peramivir, including a single-dose 300 mg regimen, showed more rapid symptom alleviation compared with placebo 11 and other NAIs.…”

“…Antiviral treatment with a neuraminidase inhibitor (NAI) can bring clinical benefits, including clearing virus, alleviating symptoms, reducing transmission, 5 and potentially improving survival 1,6 . NAI efficacy has been explored predominantly in patients with uncomplicated seasonal influenza 7‐11 .…”

Improvement of respiratory symptoms and health‐related quality of life with peramivir in influenza patients with chronic respiratory disease: Additional outcomes of a randomized, open‐label study

“…11 Peramivir is a neuraminidase inhibitor (NAI) that reduces virus titer more rapidly than oseltamivir and elicits more rapid alleviation of fever and influenza-related symptoms compared with other NAIs [12][13][14] or placebo. 15,16 Most studies have assessed the duration of fever, alleviation of influenza symptoms, or reduction of virus titer as measures of efficacy. [11][12][13][14]17,18 However, no studies have assessed cough as a separate symptom or used the COPD Assessment Test (CAT) as an evaluation of HRQoL in influenza patients with chronic respiratory disease.…”