Older adults vaccinated with Moderna’s COVID-19 vaccine were 15% less likely to be infected with COVID-19 than those vaccinated with Pfizer-BioNTech’s, according to a peer-reviewed study, published in JAMA Network on Wednesday.

The study was based on observational data from 6.3 million adults, almost 60% women and 86.5% White, with an average age of 76 years old and were inoculated with either of the two mRNA vaccines against COVID-19. 

The results showed Moderna’s COVID-19 vaccine was also marginally safer with fewer post-vaccine adverse events like pulmonary embolism and thromboembolic events reported among the said group.

“The results of this study can help public health experts weigh which mRNA vaccine might be preferred for older adults and older subgroups, such as those with increased frailty,” Dr Daniel Harris, epidemiologist and the lead author of the study said. 

His team, at the Center for Gerontology and Healthcare Research at the Brown University School of Public Health, observed two groups of older adults, one with Pfizer-BioNTech’s mRNA vaccine and the other with Moderna’s mRNA vaccine for 28 days after receiving their first doses of the vaccines. 

Overall, only 1% of all the adults who participated in the study reported adverse events. Of these, those who received Moderna’s vaccine were associated with a 4% lower risk of pulmonary embolism (sudden blockage in blood vessels) and a 2% lower risk of thromboembolic events (several conditions related to blood clotting). 

Harris stressed that the risk of adverse events from contracting COVID-19 were substantially higher than the risk of adverse events from being vaccinated by either of the two mRNA vaccines.

“But in an ideal world where we can have a choice between which vaccine product is used, we wanted to see whether one vaccine was associated with better performance for older adults and those with increased frailty,” said Harris.

Long COVID clinical trials begin recruitment

Meanwhile, the US National Institute of Health (NIH), on Tuesday, launched the second phase of clinical trials to evaluate at least four potential treatments for long COVID. As part of the RECOVER Initiative, a range of  treatments will be evaluated through these trials including drugs, biologics, and medical devices.   

“The trials are designed to evaluate multiple treatments simultaneously to identify more swiftly those that are effective,” said the NIH in a press release. 

Created to study the long-term effects of long COVID, the RECOVER Initiative is currently conducting research on how COVID-19 affects the different tissues and organs in the human body, using data from over 24,000 participants, 60 million electronic health records, and over 40 pathobiological studies. 

The information gained from these studies has been used to design the second phase in which the safety and efficacy of long COVID treatments will be studied in groups of 300-400 people. 

“Hundreds of RECOVER investigators and research participants are working hard to uncover the biologic causes of long COVID. The condition affects nearly all body systems and presents with more than 200 symptoms,” Dr Walter J. Koroshetz, director of the NIH’s National Institute of Neurological Disorders and Stroke, and co-lead of the RECOVER Initiative, added. 

“Recognizing that more than one solution is likely needed, we’ve taken the lessons learned from RECOVER participants to design rigorous clinical trial platforms that will identify treatments for persons with different symptom clusters to improve their function and well-being.”

Image Credits: Gavi .