Band Nancy Lapid
May 26 (Reuters) – The following is a summary of some recent studies on COVID-19. This includes research results that warrant further studies to confirm the results and that have yet to be certified through peer review.
Breakthrough infections can be less contagious
Fully vaccinated people who contract the coronavirus spread the infection to fewer people and are contagious for less time than people who are partially or unvaccinated, a small study from South Korea suggests.
In 173 hospital workers with COVID-19, including 50 with breakthrough infections, the researchers found that the virus had been transmitted to others in the hospital from 7% of the vaccinated group compared to 26% of the unvaccinated group, although both groups did was similar viral loads when diagnosed. In a separate group of 45 people with mild COVID-19 who were quarantined, the researchers followed four days for the six fully vaccinated people, eight days for the 11 partially vaccinated people, and eight days for the 11 partially vaccinated people long infectious virus particles in the 28 unvaccinated individuals. All of the infections were acquired before the Omicron variant was released into circulation, the researchers noted Tuesday in JAMA Network Open.
“Data from this study provide important evidence that despite the possibility of breakthrough infections, COVID-19 vaccination remains critical to curbing the spread of SARS-CoV-2,” said the researchers.
Vaccination protection dwindles faster for cancer patients
COVID-19 vaccines are effective in most cancer patients, but fewer than in the general population, and effectiveness wears off faster, according to a large study.
When the delta variant of the coronavirus was prevalent in the UK, researchers tracked 377,194 people with cancer and more than 28 million people without malignancies. After two doses of a COVID-19 vaccine from Pfizer PFE.N/BioNTech 22UAy.DE or AstraZeneca AZN.L, the vaccine’s overall effectiveness against infections was 69.8% in the general population and only slightly lower at 65.5% in cancer patients, the researchers reported Monday in The Lancet Oncology. However, three to six months later, vaccine efficacy was 61.4% in the general population but had dropped to 47% in the cancer group. The vaccines were 83.3% effective against COVID-related hospitalizations and 93.4% effective against cancer patient deaths, but that protection also wore off within three to six months, the researchers said. The vaccine’s effectiveness was lowest and declined most rapidly in people with lymphoma or leukemia. The effectiveness of the vaccine was lower and wore off more quickly in cancer patients who had received chemotherapy or radiation therapy in the past 12 months than in cancer patients who had not received any treatment in the past year.
“This study … highlights the importance of immunization refresher programs and rapid access to COVID-19 treatments for people undergoing cancer treatment,” study leader Peter Johnson, of the University of Southampton, said in a statement.
The MRI technique can provide clues to a long COVID shortness of breath
In people with persistent breathlessness after COVID-19, a special type of magnetic resonance imaging (MRI) shows lung abnormalities that conventional imaging tests fail to detect, a small study shows.
In 23 patients with months of persistent breathlessness after COVID-19, including 11 who did not require hospitalization, researchers performed hyperpolarized xenon-129 MRI, or Hp-XeMRI, to look for abnormalities in gas exchange — the way oxygen and carbon dioxide move between the lungs and blood. All participants had normal or near-normal CT scans and lung function tests, but Hp-XeMRI showed abnormalities in gas transfer in both groups, the research team reported Tuesday in Radiology. They can’t explain the abnormalities, and they don’t yet know for sure if the abnormalities are actually contributing to the patient’s symptoms. However, shortness of breath is among the most common symptoms reported by people with long COVID, and researchers hope the results of this small study will provide a clue as to the cause.
“Using Hp-XeMRI may allow us to better understand the cause of shortness of breath in long COVID patients and ultimately lead to better treatments to improve this often debilitating symptom,” said study co-author James Grist from the University of Oxford in a statement.
Click here for a Reuters graph on vaccines in development.
Vaccine race tracking http://graphics.reuters.com/HEALTH-CORONAVIRUS/VACCINE-TRACKER/xegpbqnlovq/
COVID-19 vaccination trackerhttps://graphics.reuters.com/world-coronavirus-tracker-and-maps/vaccination-rollout-and-access/
(Reporting by Nancy Lapid; Editing by Bill Berkrot)
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