Who and when to vaccinate against influenza

Expert opinion on the way forward for improving maternal influenza vaccination in India

“…Clinical experiences of influenza in pregnancy shared by the expert panel highlighted the seriousness of infection, as manifested by severe morbidity, requiring prolonged stays in intensive care and advanced medical interventions. This is in line with global reports that include the considerable clinical data collected during the 2009 influenza A/H1N1pdm09 pandemic [18][19][20].…”

“…The expert panel confirmed having regularly encountered cases of suspected viral illness in infants younger than 6 months of age and, with advances in diagnostics, confirmed cases of influenza in this age group. These early infancy cases tended to have severe influenza, as reported in this age group in other countries [19], likely due to immaturity of the immune system [3]. Since they are too young to be vaccinated, protection in this age group relies on transplacental transfer of antibodies from the mother [24] and various studies have demonstrated the effectiveness of maternal vaccination in preventing influenza infection in young infants [19].…”

“…Optimal timing for maternal influenza vaccination may also be influenced by the expected seasonal peak of disease [19]. The peak influenza season is not uniform across India: an assessment of the timing of seasonal influenza epidemics in 2010-2017 found India had two large peaks separated by several months [44].…”

The Association between Influenza Vaccination and COVID-19 and Its Outcomes: A Systematic Review and Meta-Analysis of Observational Studies

“…In the context of the COVID-19 pandemic, the dual infection of influenza and COVID-19 could bring extra burden to health care services by utilizing limited medical resources, increasing the difficulty of treatment and the uncertainty of prognosis. Annual influenza vaccination has long been recommended by WHO to prevent influenza, especially to the high-risk populations with disproportionate infection and severe complications, such as older adults (aged > 65 years) and pregnant women [6]. To date, no highly effective pharmaceutical treatment is available against COVID-19 [7].…”

Characteristics of Children With Reactivation of SARS-CoV-2 Infection After Hospital Discharge

“…They were also more likely to have negative chest CT findings and had a higher neutrophil count, neutrophil percentage, and NLR, although these differences were not significant because of the small sample size. These findings could be attributable to the fact that younger children are exposed to a high number of viral infections and vaccination 7,8 ; for example, in one study, the hospitalization rate for confirmed influenza in children aged 0 to 5 months was 4.5 per 1000 children compared with that of 0.3 per 1000 in children aged 2 to 5 years. 8 Higher exposure to viruses could significantly enhance their immunological function and result in high clearance of the virus.…”