Using Metformin to Treat Patients With Post-COVID-19, Medical and Mental Conditions After Infection, and More

Outpatient Treatment Reduces Post-COVID-19 Risk1

Post-COVID-19—long COVID—is an emerging chronic illness that has affected approximately 7.5% of adults in the United States.2 A team of researchers evaluated whether the use of metformin, ivermectin, or fluvoxamine soon after COVID-19 infection reduces the risk of developing post-COVID-19.

Using a decentralized, randomized, quadruple-blind, parallel-group, the phase 3 trial included adults aged 30 to 85 years with overweight or obesity who had COVID-19 symptoms fewer than 7 days. The participants had a documented positive polymerase chain reaction or antigen test result for COVID-19 within 3 days before study enrollment (n = 1431).

Between December 2020 and January 2022, 1323 participants received a dose of treatment. Of the total who received treatment, 1126 consented to long-term follow-up and completed at least one survey after the assessment for post-COVID-19.

In total, 564 participants received metformin as their treatment and 562 received matched placebo (a subset were also randomly assigned to receive ivermectin or fluvoxamine). Overall, 6.3% of participants (n = 93) who received metformin reported a diagnosis of post-COVID-19 by day 300.

“Outpatient treatment with metformin reduced long COVID incidence by about 41%, with an absolute reduction of 4·1%, compared with placebo. Metformin has clinical benefits when used as outpatient treatment for COVID-19 and is globally available, low-cost, and safe,” the researchers concluded.

Medical, Mental Health Conditions After COVID-19 Infection3

In a recent study, researchers sought to determine the incidence of people developing new cardiovascular, neurological, mental health, and inflammatory autoimmune conditions post-hospitalization for COVID-19.

The researchers conducted a population-based cohort study that included all adults hospitalized with COVID-19 (n= 379,366) between April 2020 and October 2021. The main outcome of the study was a new occurrence of 13 prespecified conditions within year 1 year of hospitalization.

Of the total, 26,499 people survived after hospitalization. An increased 1-year risk of venous thromboembolic disease—compared with influenza—was associated with hospitalization for COVID-19. But despite this increased risk, the researchers found that there was “no increased risk of developing selected ischemic and nonischemic cerebrovascular and cardiovascular disorders, neurological disorders, rheumatoid arthritis, or mental health conditions compared with influenza or sepsis cohorts,” the authors wrote.

“Many of the postacute consequences of COVID-19 may be related to the severity of infectious illness necessitating hospitalization rather than being direct consequences of infection with SARS-CoV-2,” the researchers concluded.

Vaccine Effectiveness in Protecting Pediatric Patients from Omicron Variant4

In an observational cohort study, a group of researchers examined the effect of vaccination for COVID-19 and previous SARS-CoV-2 infection on omicron infection in children aged 12 years or younger.

The researchers used data from the North Carolina COVID-19 Surveillance System and the COVID-19 Vaccine Management System where they evaluated the use of BNT162b2 and mRNA-1273 vaccines in patients aged 11 years of younger (n = 1,368,721). Researchers found that the effectiveness of primary vaccination against COVID-19—compared with being unvaccinated—was: (1) 59.9% at 1 month, (2) 33.7% at 4 months, and (3) 14.9% at 10 months, all after the first dose.

Further, compared with primary vaccination only, the researchers found that the effectiveness of a monovalent booster dose after 1 month was 24.4% and the use of a bivalent booster dose was 76.7%. Additionally, the effectiveness of omicron infection against reinfection was found to be 79.9% after 3 months and 53.9% after 6 months.

For children aged 0 to 4 years, the effectiveness of omicron against reinfection after the first dose of vaccination was 77.3% after 3 months and 64.7% after 6 months.

“The BNT162b2 and mRNA-1273 vaccines were effective against omicron infection and severe outcomes in children younger than 12 years, although the effectiveness decreased over time,” the researchers concluded. “Bivalent boosters were more effective than monovalent boosters. Immunity acquired via omicron infection was high and waned gradually over time. These findings can be used to develop effective prevention strategies against COVID-19 in children younger than 12 years.”


  1. Bramante CT, Buse JB, Liebovitz DM, et al. Outpatient treatment of COVID-19 and incidence of post-COVID-19 condition over 10 months (COVID-OUT): a multicentre, randomised, quadruple-blind, parallel-group, phase 3 trial. Lancet Infect Dis. Published online June 8, 2023. doi:10.1016/S1473-3099(23)0299-2
  2. Nearly one in five American adults who have had COVID-19 still have “long COVID.” Centers for Disease Control and Prevention. June 22, 2022. Accessed July 6, 2023.
  3. Quinn KL, Stukel TA, Huang A, et al. Comparison of medical and mental health sequelae following hospitalization for COVID-19, influenza, and sepsis. JAMA Intern Med. Published online June 20, 2023. doi:10.1001/jamainternmed.2023.2228
  4. Lin DY, Xu Y, Gu Y, et al. Effects of COVID-19 vaccination and previous SARS-CoV-2 infection on omicron infection and severe outcomes in children under 12 years of age in the USA: an observational cohort study. Lancet Infect Dis. Published online June 16, 2023. doi:10.1016/S1473-3009(23)00272-4