Study: B117 variant 45% more transmissible than wild-type COVID-19
A study yesterday in Cell Reports Medicine shows the B117 variant, first identified in the United Kingdom in December, is 45% more transmissible than the original, wild-type COVID-19 virus, but Pfizer's mRNA vaccine protected elderly populations against infections caused by the variant.
The study was based on cases documented in Israel from Dec 6, 2020, through Feb 10, 2021. Within 3.5 weeks of detection, B117 was the dominant strain in Israel. But the nation took a three-pronged approach to controlling a spike in cases, including expanded polymerase chain reaction (PCR) testing, focused surveillance in nursing homes, and prioritized vaccination of those 60 years and older with BNT162b2, the two-dose Pfizer-/BioNTech vaccine.
Based on results from 300,000 PCR tests for COVID-19, researchers showed only 5% of the positive results were B117 on Dec 24. By the end of January, that number jumped to 90%, and currently 99.5% of all COVID-19 cases in Israel involve B117.
"To explain this dramatic increase, we compared the R [reproductive] number of the SARS-CoV-2 virus with the R of the British variant. In other words, we posed the question: How many people, on the average, contract the disease from every person who has either variant? We found that the British variant is 45%—almost 1.5 times—more contagious," said lead author Ariel Munitz, PhD, a professor at Tel Aviv University, in a press release.
New cases were rising until 50% of the 60-and-older population received the first dose of the Pfizer vaccine, the authors said. After 2 weeks following the first dose, a significant drop in new cases among the elderly were observed.
The authors concluded that they can expect a drop in cases among at-risk groups once 50% of that population has been vaccinated, even in the face of highly transmissible variants.
Apr 20 Cell Rep Med study
Apr 20 Tel Aviv University press release
Some dietary supplements may cut risk of COVID-19 infection
Use of certain dietary supplements may reduce the risk of testing positive for COVID-19, according to a large observational study of people in the United Kingdom who used a COVID-19 symptom tracking app. UK-based researchers detailed their findings in the latest issue of BMJ Nutrition, Prevention, & Health. Supplements associated with risk reduction included multivitamins, omega-3, probiotics, and vitamin D.
Dietary supplements have the potential to support the immune system, but it's not known which ones are associated with a lower risk of getting sick with COVID-19. Sales of supplements rose steeply during earlier pandemic months.
To explore which ones might be linked to lower levels of infection, the UK team explored data from the 372,720 users of the COVID-19 Symptom Study app, which recorded several measures, including regular use of supplements in May, June, and July 2020 during the United Kingdom's first surge. Of the subscribers, 175,652 took supplements; 67% were women, and more than half were overweight. Overall, 23,521 tested positive for SARS-CoV-2.
Probiotics, omega-3, multivitamins, and vitamin D were associated with a respective reduced risk of 14%, 12%, 13%, and 9%. The associations were seen only in women. The team observed similar patterns for app users from the United States and Sweden. Researchers didn't see associations with other supplements, including vitamin C, zinc, or garlic.
Scientists concluded that though the study was observational and didn't establish a cause, the modest effect they saw was significant, and they called for large clinical trials to guide evidence-based therapeutic recommendation regarding supplement use.
Apr 19 BMJ Nutr Prev Health abstract
Apr 19 BMJ press release