This week's roundup of some of the latest scientific studies on the novel coronavirus and efforts to find treatments and vaccines for COVID-19 finds higher risk of complications and death in obese men, offers promising results for partially vaccinated households and introduces a new drug that could fight cytokine storms in patients.
Impact of obesity on COVID-19 risks may be greater in men
The known increased risk of severe COVID-19 and death linked to obesity may be even more pronounced for men than women, new data suggests.
Researchers studied 3,530 hospitalized COVID-19 patients with an average age of 65, including 1,469 who were obese. In men, moderate obesity was associated with a significantly higher risk of developing severe disease, needing mechanical breathing assistance and dying from COVID-19. The threshold for moderate obesity is a body mass index (BMI) of 35. In a five-foot, five-inch tall (1.65 m) adult, that would correspond to a weight of 210 pounds (95 kg). In women, however, only a BMI of 40 or higher, indicating severe obesity, was linked with the increased risks.
In a report published in the European Journal of Clinical Microbiology & Infectious Diseases, the researchers note that while obesity is known to be linked with body-wide inflammation, patients' levels of inflammatory proteins did not appear to explain the association between obesity and severe illness. For now, they conclude, "particular attention should be paid" to protecting patients with obesity from the coronavirus, "with priority to vaccination access, remote work, telemedicine, and other measures given the higher risk of adverse outcomes once they are diagnosed with COVID-19."
New drug helps COVID-19 patients breathe on their own
When a new monoclonal antibody drug was added to treatments being given to hospitalized COVID-19 patients who were still breathing on their own, the drug – lenzilumab from Humanigen Inc – significantly improved their odds of not needing invasive mechanical ventilation, researchers found.
The 540 patients in the randomized trial were already receiving a variety of standard treatments. Half of them also received lenzilumab via three intravenous infusions. In a paper posted on medRxiv ahead of peer review, the research team reported that patients in the lenzilumab group had a 54% better chance of surviving without needing mechanical ventilation. In patients receiving steroids and Gilead Sciences antiviral drug remdesivir, the addition of lenzilumab improved survival without the need for mechanical ventilation by 92%. In patients under age 85 whose immune system was in the early stages of triggering a life-threatening inflammatory response, lenzilumab improved the odds of ventilator-free survival by nearly three-fold.
Humanigen Chief Executive and study co-author Dr. Cameron Durrant said his team believes the results "indicate a substantial improvement in COVID-19 treatment."
Vaccines protect unvaccinated household members, too
Compared to an unvaccinated COVID-19 patient, a vaccinated person who nevertheless becomes infected with the coronavirus has a much lower risk of transmitting the virus to household members, a large U.K. study found.
Researchers at Public Health England studied more than 365,000 households with a first COVID-19 infection, including more than 24,000 households in which the so-called "index case" of COVID-19 was someone who had received at least one dose of either the Pfizer-BioNTech vaccine or the Oxford-AstraZeneca vaccine.
When the first dose had been given at least 21 days previously – as was the case in 4,107 of the households studied – the risk of virus transmission from vaccinated individuals to their household members was 40% to 50% lower than the risk of transmission from COVID-19 patients who had not been vaccinated, the researchers found. The effects were similar for both the Pfizer and AstraZeneca vaccines and started to become evident around 14 days after the first dose, according to a report posted ahead of peer review on Knowledge Hub.
Along with the vaccines' success at preventing infections and reducing the severity of infections that do occur, the new findings show they are "associated with reduced likelihood of household transmission ... highlighting important wider benefits to close contacts," the authors conclude.