Seasonal influenza viruses typically cause annual epidemics worldwide infecting 5-15% of the human population. However, during the first two years of the COVID-19 pandemic, seasonal influenza virus circulation was unprecedentedly low with very few reported infections. The lack of immune stimulation to influenza viruses during this time, combined with waning antibody titres to previous influenza virus infections, could lead to increased susceptibility to influenza in the coming seasons and to larger and more severe epidemics when infection prevention measures against COVID-19 are relaxed. Here, based on serum samples from 165 adults collected longitudinally before and during the pandemic, we show that the waning of antibody titres against seasonal influenza viruses during the first two years of the pandemic is likely to be negligible. Using historical influenza virus epidemiological data from 2003-2019, we also show that low country-level prevalence of each influenza subtype over one or more years has only small impacts on subsequent epidemic size. These results suggest that the risks posed by seasonal influenza viruses remained largely unchanged during the first two years of the COVID-19 pandemic and that the sizes of future seasonal influenza virus epidemics will likely be similar to those observed before the pandemic.

The COVID-19 outbreak has thrown the world into an unprecedented crisis. It has posed a challenge to scientists around the globe who are working tirelessly to combat this pandemic. We herein report a set of molecules that may serve as possible inhibitors of the SARS-CoV-2 main protease. To identify these molecules, we followed a combinatorial structure-based strategy, which includes high-throughput virtual screening, molecular docking and WaterMap calculations. The study was carried out using Protein Data Bank structures 5R82 and 6Y2G. DrugBank, Enamine, Natural product and Specs databases, along with a few known antiviral drugs, were used for the screening. WaterMap analysis aided in the recognition of high-potential molecules that can efficiently displace binding-site waters. This study may help the discovery and development of antiviral drugs against SARS-CoV-2.

“India fights Corona”, proclaims the media. ‘Stay home’, ‘social distancing’, ‘lock down’ are the phrases ringing in every home. The Corona pandemic has drawn the attention of many scientists to fight against the virus. We report herein, a set of newly identified molecules which can presumably act as potential inhibitors of Covid-19 main protease. A fast mode approach using a combinatorial structure based strategy which includes high throughput virtual screening, molecular docking, water map calculations and data base search was applied to identify these molecules. The PDB structures, 5R82, 6Y2G were used as the basis for this study. Data bases viz., Enamine, Drug Bank, Natural product, Specs and few antiviral drugs were used for screening. Water map analysis yielded insights into the design of more potential molecules. Considering the need of the hour, this study may help in the discovery and development of anti-viral drugs against Covid-19.