Tag: 26/1/21

Sceptical South Africans Want More Vaccine Info

Professor Carin Runciman, Director of the Centre for Social Change at UJ, has said that most people who are sceptical about COVID vaccines simply want more information. 

An online survey of 10 000 South African adults conducted with the Human Sciences Research Council showed that 67% were likely to take the vaccine if it were offered to them. Runciman said that many of the participants had indicated that they wanted more information before they could decide to take it.

Government and scientists came for criticism recently for giving mixed messages about vaccines, which are a few days away from their first rollout in South Africa. With the first million doses arriving in SA from the end of January, an ambitious target of 31 000 vaccinations a day has been announced, though with few firm details. The majority (70%) of the vaccines are to be AstraZeneca, although given their delays in supplying the EU and the bloc’s subsequent restrictions on vaccine exports, that may impact on SA’s vaccination programme.

Opinions also differed according to age and race. In a very strange result, those with higher levels of education were less likely to want to take a vaccine than those with a lower level. Age and race also played a factor, although no explanation was offered for the discrepancy. “Black African adults were more likely to want to take the vaccine – 69% for black African adults, 55% for white adults – those who [are] older are more likely to want to take the vaccine compared to those that are younger. Those that have a less than matric education are much more likely to want to take the vaccine than those with a tertiary education.”

Source: Eyewitness News

Happier Memories in Teens Linked to Less Alcohol and Marijuana Use

A study of teenage American students has found that happy childhood memories, along with a positive view of the present and outlook for the future are associated with reduced alcohol use, binge drinking and marijuana use. 

Researchers say that action is needed because COVID restrictions have left teenagers isolated and vulnerable. Quarantining results in anxiety, stress and feelings of loneliness in children and adolescents, and the closure of schools has also taken away mental health support systems which some teenagers may rely on.

John Mark Froiland of Purdue University said: “School often seems a source of stress and anxiety to students. This puts them at greater risk of not participating in lessons, getting lower grades and of substance misuse. Many teenagers also aren’t engaging with online learning during Covid or have lower engagement levels.

“But they’re more likely to be enthusiastic learners and not use drink and drugs if teachers take time to build more positive relationships with them. They can help students see that everything they’re learning is truly valuable. Parents have a role to play too.”

The study was based on questionnaires completed by 1961 student participants in San Francisco, of which 53% were female. The researchers examined how happy the students believed their childhood was, how happy they were currently and how optimistic they were about their futures.

In addition, they looked at alcohol and marijuana use over the past 30 days and binge use, as well as academic grades, behaviour during lessons and motivation.

Positive attitudes towards the past, present and future was associated with lower alcohol use, binge drinking and marijuana use, while the reverse was true for negative attitudes.

An optimistic outlook increased the likelihood that they would be motivated and focus on learning. Other findings included drinking being associated with marijuana use, and that girls had better behavioural engagement than boys.

Source: News-Medical.Net

Journal information: Froiland, J.M., et al. (2020) Positive and negative time attitudes, intrinsic motivation, behavioral engagement and substance use among urban adolescents. Addiction Research & Theory. doi.org/10.1080/16066359.2020.1857740.

Breast Cancer in Mice Inhibited by Restricted Feeding Times

Restricting calorie intake to an eight-hour window coinciding with physical activity reduced breast cancer risk in female mouse models.

Researchers from University of California San Diego School of Medicine, Moores Cancer Center and Veterans Affairs San Diego Healthcare System (VASDSH) found that the restricted feeding times, which are kind of circadian rhythm-linked intermittent fasting, enhanced metabolic health and tumour circadian rhythms in female mice with obesity-driven postmenopausal breast cancer. Breast cancer is the second most common cancer in US women, after skin cancer.

“Previous research has shown that obesity increases the risk of a variety of cancers by negatively affecting how the body reacts to insulin levels and changing circadian rhythms,” explained senior author Nicholas Webster, PhD. professor at UC San Diego School of Medicine and senior research career scientist at VASDSH. “We were able to increase insulin sensitivity, reduce hyperinsulinemia, restore circadian rhythms and reduce tumor growth by simply modifying when and for how long mice had access to food.”

Female mouse models mimicking postmenopausal hormone conditions were used to investigate if time-restricted feeding of obese mice affected the tumour growth and development, and reduced metastasis to the lungs. The mice were split into three groups, one with constant access to food, one with access for eight hours at night when they have the greatest activity, and the last was fed an unrestricted low-fat diet.

Obesity and menopause disrupt the circadian rhythm, with increased risk of insulin resistance and thereby chronic diseases such as cancer. A number of cancers are known to be associated with insulin resistance, such as breast cancer and pancreatic cancer. High insulin levels in obese mice drive tumour growth. Artificially increasing insulin levels has been shown to accelerate tumour growth whilst lowering them is similar to the effect of limiting eating.
Manasi Das, PhD, postdoctoral fellow in the Webster lab and first author, said: “Time-restricted eating has a positive effect on metabolic health and does not trigger the hunger and irritability that is associated with long-term fasting or calorie restriction. Through its beneficial metabolic effects, time-restricted eating may also provide an inexpensive, easy to adopt, but effective strategy to prevent and inhibit breast cancer without requiring a change in diet or physical activity.”

Webster believes that time-restricting eating warrants further investigations as it may present a way to reduce breast cancer risk, or that of cancer in general.

“The increase in risk of breast cancer is particularly high in women who are overweight and have been through menopause. For this reason, doctors may advise women to adopt weight loss strategies to prevent tumor growth,” said Das. “Our data suggests that a person may benefit from simply timing their meals differently to prevent breast cancer rather than changing what they eat.”

Source: Medical Xpress

Journal information: Manasi Das et al. Time-restricted feeding normalizes hyperinsulinemia to inhibit breast cancer in obese postmenopausal mouse models, Nature Communications (2021). DOI: 10.1038/s41467-020-20743-7

EU to Restrict AstraZeneca Exports to Tackle Vaccine Shortage

In response to AstraZeneca’s COVID vaccine production and delays, the European Union has warned that it will tighten exports of the company’s vaccine to countries outside its borders.

EU Health Commissioner Stella Kyriakides warned it would “take any action required to protect its citizens”, adding that she had requested detailed delivery schedules and a meeting next week with the company. She added that “in the future, all companies producing vaccines against Covid-19 in the EU will have to provide early notification whenever they want to export vaccines to third countries”.

The vaccine, developed by Oxford University and the British-Swedish company AstraZeneca, is still yet to be approved in the EU but should receive it by the end of January, with distribution set to start on the 15th of February. The EU has been suffering from a number of vaccination programme setbacks, including a previous announcement last week from Pfizer that its own deliveries were being delayed in order to upgrade manufacturing capabilities at a plant in Belgium, provoking ire amongst EU politicians. Italy’s PM has resigned over handling of the pandemic.

The EU had signed a deal in August to secure 300 million doses from AstraZeneca, with an option for another 100 million. Last week, AstraZeneca had announced a slowdown in delivery due to “reduced yields at a manufacturing site within our European supply chain”. The problem is thought to be from a manufacturing plant also in Belgium, which is run by an AstraZeneca partner firm. The exact size of the shortfall is not known but some believe it to be a drop of 31 million doses, or 60% of those meant to be delivered by the end of the quarter.

Where this leaves low and middle-income countries counting on the Oxford/AstraZeneca vaccines is unclear, but it certainly will add to mounting tension between countries seeking vaccines for their populations amidst the spread of more contagious COVID variants. President Cyril Ramaphosa warned in an address to the World Economic Forum that vaccine nationalism was a growing concern and threat to global recovery. The African Union’s vaccine task team has thus far managed to secure only 270 million doses.

Source: BBC News