Following the record surge in COVID-19 cases during the Omicron-driven wave, some 58 percent of the U.S. population overall and more than 75 percent of younger children have been infected with the coronavirus since the start of the pandemic, according to a U.S. nationwide blood survey released on April 26.

COVID-19 was the third leading cause of death in the United States for the second year in a row in 2021, with death rates rising for most age groups, a government study showed on April 22.

Unvaccinated people infected with the Omicron variant are unlikely to develop immune responses that will protect them against other variants of the coronavirus, a new study suggests. Additionally, the average number of global deaths from COVID-19 were 6 percent higher on weekends compared to weekdays throughout the pandemic, according to statistics reported to the World Health Organization between March 2020 and March 2022.

A second Global COVID-19 Summit will be held virtually during May for countries to discuss efforts to end the pandemic and prepare for future health threats, according to a joint statement on April 18.

A fourth dose of the COVID-19 vaccine from Pfizer and BioNTech provided significant added protection against severe disease, hospitalization and death for at least a month in older individuals, according to a study from Israel conducted when the Omicron variant was dominant. Additionally, new findings suggest patients with COVID-19 may have an increased risk of rare vision-threatening blood clots in the eye for months afterward.

Mallinckrodt plc announced the publication of findings from a retrospective chart review study assessing the real-world use and outcomes of INOmax (nitric oxide) gas, for inhalation therapy in hospitalized patients with COVID-19 and mild-to-moderate acute respiratory distress syndrome (ARDS), a disorder in which fluid leaks into the lungs, making breathing difficult or impossible. The results of the study were published in the peer-reviewed journal Drugs in Context.

An experimental drug being developed by RedHill Biopharma Ltd. that improved outcomes in a randomized trial involving severely ill COVID-19 patients infected with earlier versions of the coronavirus is showing promise against the Omicron variant in test tube experiments, researchers said. Additionally, people living with well-controlled HIV infections are likely to have immune responses to the mRNA COVID-19 vaccines from Moderna and from Pfizer/BioNTech similar to those of otherwise healthy individuals, according to new data.

Although people who recover from COVID-19 usually gain some immune defenses against reinfection, they get additional protection from vaccines, especially against severe disease, according to two studies published on March 31 in The Lancet Infectious Diseases. Additionally, two gold-standard trials published in The New England Journal of Medicine on March 30 help settle questions about two controversial therapies touted by many early in the pandemic with decidedly mixed results – failure for the antiparasite drug ivermectin and success for antibody-rich blood plasma from COVID-19 survivors.

Anosmia is a recognized symptom of COVID-19, with anywhere between 30% to 80% of sufferers reporting loss of smell.

Senior citizens who received a second booster of the Pfizer-BioNTech COVID-19 vaccination had a 78 percent lower mortality rate from the disease than those who got one only, a study from Israel showed on March 27.