HCFI Dr KK Aggarwal Research Fund

With inputs from Dr Monica Vasudev

Delta variant spreads by cell-to-cell fusion

Compared to the spike protein on earlier versions of the coronavirus, the spike on the Delta variant is better able to break into lung cells and fuse them together, according to a preprint posted on BioRxiv.

Spread by cell-to-cell fusion allows the virus to spread faster in infected people and partially hide from the immune system. And by spreading via cell-to-cell fusion, the virus reduces its risk of encountering immune system cells that might attack and inactivate it, said Markus Hoffman of Georg-August-University Göttingen in Germany, co-author of the study. These "skills" might make the Delta variant more transmissible, and the resulting illness more severe. It was also found that although the Delta variant can evade antibodies, it is not completely resistant (Source: Medscape).

Germany strongly recommends mixing of Covid-19 vaccines

Germany has become one of the first countries to make a strong recommendation for the mixing of Covid-19 vaccines on the basis of efficacy. On Thursday, the German Standing Committee on Vaccination (STIKO) said that people who receive a first dose of the Oxford-AstraZeneca vaccine “should get an mRNA vaccine as their second dose, regardless of their age.” STIKO said that "current study results" show that the immune response generated after a mixed dose vaccination "is clearly superior." (Source: CNN)

Sickle cell disease patients with history of pain are at risk of severe Covid-19

Patients with sickle cell disease (SCD) who have a history of disease-related comorbidities were found to be at greater risk for worse COVID-19 outcomes. A new study published in the journal Blood Advances has shown that children were more likely to require hospital admission for Covid19, if they had frequent prior acute care visits for pain (relative risk [RR] 2.15, P<0.0001), as well as sickle cell disease-related heart and lung comorbidities (RR 1.61, P=0.0001).

• Prior acute care visits for pain were the most common sickle cell disease-related comorbidity among both children (55.5%) and adults (78.5%).
• History of pain was also found to be a risk factor for hospitalization in adults (RR 1.78, P=0.002).
• Children with a history of pain (RR 3.09, P=0.009), SCD-related heart and lung comorbidities (RR 1.76, P=0.03), and SCD-related renal comorbidities (RR 3.67, P<0.0001) were at a higher risk of developing serious Covid illness.

The researchers said, “SCD is a chronic inflammatory disease. An infection like COVID-19 that targets the lungs can lead to decreased oxygenation and blood hypoxia, which promotes sickling, vaso-occlusive episodes and pain.” Patients at high risk should consider vaccination (Source: Medpage Today, July 1, 2021)

Repurposing hepatitis C antiviral drugs as possible treatment of Covid-19

An antiviral combination Sofosbuvir/ledipasvir used to treat hepatitis C infection and an antiprotozoal drug nitazoxanide may eliminate SARS-CoV-2, according to preliminary results presented at the International Liver Congress 2021. Sofosbuvir/ledipasvir was particularly efficacious. Molecular docking studies, which use computation to find ligands that bind to proteins, suggested that both sofosbuvir/ledipasvir and nitazoxanide might block key proteins in SARS-CoV-2.

The study grouped 190 patients with mild and moderate COVID-19 infections into three groups. One group was given sofosbuvir/ledipasvir, another group also received nitazoxanide. All the three groups received also standard care. The effect of sofosbuvir/ledipasvir appeared within 5 days and viral clearance was achieved in most patients within 2 weeks. Nitazoxanide had a weaker effect but still appeared to achieve a benefit. No serious adverse events or mortality was recorded (Source: Medscape)