Category: COVID

Categories : COVIDTags :

Kenya’s Waves Driven by Socio-economic Differences and Variants

On By ModernMedia
Phot by Martin Sanchez on Unsplash

By combining COVID surveillance data with population mobility data from smartphones, infectious disease modellers have explained the evolution of the first three COVID waves to hit Kenya. 

Sequential waves of transmission through different socio-economic groups, followed by infection boosted by the introduction of new variants.

In order to forecast future outbreaks, the team had to develop a model to explain current waves. The work brought together COVID antibody survey data, PCR case data, genomic variant data and Google mobility data, seeking to find an explanation to the waves of COVID in Kenya. The aim was to then provide policy-based forecasts on future waves in the country based on the model findings.

Lower socio-economic groups have been identified as vulnerable to SARS-CoV-2 in the global South due to living in densely populated informal settlements, with reduced access to sanitation, and relying on daily mobility for informal employment. In contrast, those from higher socio-economic groups with job security can work from home, physically distance and readily access water and sanitation, thereby decreasing transmission.
The modelling results show that differences in mobility and contact rates between high and low socio-economic groups within Kenya explain the differences between the first and second waves. In the initial phase of the epidemic (from March 2020), individuals in high socio-economic groups could reduce their mobility and contact rates, but individuals in lower socio-economic groups could not. This resulted in transmission among individuals in lower socio-economic groups that was observed as the first wave in urban centres. As these individuals recovered from infection and became immune, at least temporarily, the first wave ended.

By the onset of the second wave (from October 2020), individuals in high socio-economic groups had increased their contact rates and mobility. This led to transmission among individuals in the high socio-economic groups, and also involved rural as well as urban areas. The second wave then appeared to end as individuals cleared the virus and became immune, at least for the time being. However, the advent of the more infectious Beta and Alpha variants resulted in a third wave among both high and low socio-economic groups (from March 2021).

 In many other African countries, there have been multiple waves that are not fully explained by timing of restrictions, and as they have similar urban socio-economic groupings, the researchers speculate that these explanations may have wider applicability. Understanding the causation of such multiple waves is critical for forecasting hospitalisation demand and the likely effectiveness of interventions including vaccination strategy.

Dr Samuel Brand from the University of Warwick said: “This is one of the first studies to consider detailed predictions of the dynamics of COVID across multiple waves in tropical sub-Saharan Africa. We believe this sets a new standard for the type of public health modelling work that can be conducted in real-time in developing countries.”

Dr John Ojal of KEMRI-Wellcome Trust Research Programme said: “There are highly detailed modelling studies of this nature in High Income Countries, but there have been none previously in tropical sub-Saharan Africa.”

The study has been published in the journal Science.

Source: University of Warwick

Categories : COVIDTags :

Vaccinated Individuals Reduce COVID Risk for Nonimmune People

On By ModernMedia
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As the number of family members with COVID immunity from prior infection or vaccination increased, there was a decrease in infection and hospitalisation risk for nonimmune people. 

This is shown in a Swedish study conducted by researchers at Umeå University and published in JAMA Internal Medicine.

“The results strongly suggest that vaccination is important not only for individual protection, but also for reducing transmission, especially within families, which is a high-risk environment for transmission,” said Peter Nordström, professor of geriatric medicine at Umeå University.

Evidence shows that vaccines greatly reduce the severity of COVID including the Delta variant but there less is known how vaccination affects transmission of the virus in high-risk environments, eg within families.

The researchers found that there was a dose-response association between the number of immune individuals in each family and the risk of infection and hospitalisation in non-immune family members. Specifically, non-immune family members had a 45 to 97% reduced risk of infection and hospitalisation, as the number of immune family members increased.

The study is a nationwide, registry-based study of more than 1.8 million individuals from more than 800 000 families, drawing on various databases. In the analysis, the researchers quantified the association between the number of family members with immunity against COVID and the risk of infection and hospitalisation in nonimmune individuals. The researchers accounted for factors such as differences in age, socioeconomic status, clustering within families, and several diagnoses previously identified as risk factors for COVID in the Swedish population.

“It seems as if vaccination helps not only to reduce the individual’s risk of becoming infected, but also to reduce transmission, which in turn minimises not only the risk that more people become critically il, but also that new problematic variants emerge and start to take over. Consequently, ensuring that many people are vaccinated has implications on a local, national, and global scale,” said study co-author Marcel Ballin, doctoral student in geriatric medicine at Umeå University.

Source: Umeå University

Categories : COVID Immune SystemTags :

Differences in Natural and Vaccine-induced COVID Immunity Revealed

On By ModernMedia
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A new study recently published in Nature has found that immune protection resulting from COVID protection creates lasting effects in memory B cells.

Unlike circulating antibodies, which peak soon after vaccination or infection only to fade a few months later, memory B cells can remain to ward off severe disease for decades. They also evolve over time, learning to produce successively more potent ‘memory antibodies’ that are more effective at neutralising the virus and with better adaptation to variants.

Though vaccination instils higher levels of circulating antibodies than natural infection, the study suggests that not all memory B cells are created equal. While vaccination gives rise to memory B cells that evolve over a few weeks, natural infection births memory B cells that continue to evolve over several months, producing highly potent antibodies adept at eliminating even viral variants.

Though the findings suggest an advantage from natural infection over vaccination, this does not outweigh the dangers of illness and death from COVID, the researchers warn.

“While a natural infection may induce maturation of antibodies with broader activity than a vaccine does – a natural infection can also kill you,” explained Professor Michel C. Nussenzweig, head of Rockefeller’s Laboratory of Molecular Immunology. “A vaccine won’t do that and, in fact, protects against the risk of serious illness or death from infection.”

When any virus enters the body, immune cells immediately release circulating antibodies, which decay at variable rates depending on the vaccine or infection. They may confer protection for months or years but then dwindle in number, allowing possible reinfection.

Long term protection is provided by memory B cells that produce memory antibodies. Studies suggest that memory B cells for smallpox last at least 60 years after vaccination; those for Spanish flu, nearly a century. And while memory B cells don’t necessarily block reinfection, they can prevent severe disease.

Recent studies have suggested that within five months of receiving a vaccine or recovering from a natural infection, some no longer retain sufficient circulating antibodies to keep the novel coronavirus at bay, but memory B cells remain vigilant. Until now, however, scientists did not know whether the vaccines could be expected to provide the sort of robust memory B cell response seen after natural infection.

Prof Nussenzweig and colleagues resolved to tease out any differences in memory B cell evolution by comparing blood samples from convalescent COVID patients to those from never-infected mRNA-vaccinated individuals.

Vaccination and natural infection elicited similar numbers of memory B cells, which rapidly evolved between the first and second dose of the Pfizer and Moderna vaccines, producing increasingly potent memory antibodies. But after two months, progress stalled. The memory B cells were present in large numbers and expressed potent antibodies, but the antibodies were not getting any stronger. Also, although some of these antibodies were able to neutralize Delta and other variants, there was no overall improvement in breadth.

The researchers found that in convalescent patients, however, memory B cells continued to evolve and improve up to one year after infection. With every memory B cell update, more potent and more broadly neutralising memory antibodies were coming out.

There are several potential reasons that memory B cells produced by natural infection might be expected to outperform those produced by mRNA vaccines, the researchers said.

It is possible that the body responds differently to viruses that enter through the respiratory tract than those that are injected. Or perhaps an intact virus goads the immune system in a way the vaccines’ spike protein antigens simply cannot. It may also be possible that the virus persists in the naturally infected for weeks, giving the body more time to mount a robust response. The vaccine, on the other hand, is flushed out of the body mere days after triggering the desired immune response.

Memory B cells appear to undergo limited bouts of evolution in response to mRNA vaccines, a finding which may have significant implications for booster shots. A booster with the current mRNA vaccine would likely stimulate memory cells to produce antibodies strongly protective against the original virus and somewhat less so against the variants, Prof Nussenzweig said.

“When to administer the booster depends on the object of boosting,” he said. “If the goal is to prevent infection, then boosting will need to be done after 6 to 18 months depending on the immune status of the individual. If the goal is to prevent serious disease, boosting may not be necessary for years.”

Source: Rockefeller University

Categories : COVIDTags :

Digital COVID Vaccination Certificates for South Africa are Here

On By ModernMedia
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People vaccinated in South Africa can now download their digital COVID vaccination certificates. The service officially went live on Friday, and was announced by the Minister of Health, Dr Joe Phaahla.

Addressing a media briefing, Dr Phaahla said the certificate could be used for travel and tourism, sport and recreation events, music festivals, shops that are providing discounts and prizes for people who are vaccinated.

“Our role is to make this tool available to the nation to provide people with the proof of vaccination so they can have access to the many amenities and activities that some have been missing…

“The vaccination certificate was introduced over the last three days while it was in the testing phase but some people have been able to upload it to their cell phones.

“We are launching the first phase of the certificate – there’s going to be a lot more improvements in the next two months [with regards to] the safety and security of the certificate but it is ready for use,” said the Minister.

The certificate was developed by the Department of Health and the Council for Scientific and Industrial Research (CSIR) and can be found at https://vaccine.certificate.health.gov.za.

The project manager for the National Electronic Vaccination Data System (EVDS), Milani Wolmarans, said the certificate can be downloaded through a web portal by anyone who has received the COVID vaccine in South Africa.

“You’ll need your vaccination code from the SMS you received after your vaccination, South African ID or Foreign Passport number or Asylum or Refugee number. This should be the same document that you presented when you got vaccinated and the cell phone you included on your registration,” she said.

Vaccination codes will be sent via SMS over the next four day, and also be accessed from the COVID call centre on 0800 029 999.

“With regards to the recognition of the digital certificate, most countries around the globe would accept the certificate. It is, however, dependent on the policy of the country that you would be visiting and also what their verification requirements would be.

“Towards the end of the next two months, there will be an app that you can use to download the certificate,” Wolmarans said.

The Minister also welcomed South Africa’s removal from the UK’s red list, which will take effect on Monday 11 October.

“We are also pleased with the UK government announcement that it is taking our country from the red list – meaning more easy travel between people from South Africa and the UK. The UK will be recognising the certificate that we are launching,” Dr Phaahla said.

Importantly, the UK will also now recognise South African COVID vaccination certificates.

Source: SA News.Gov

Categories : COVID Substance UseTags :

People With Substance Use Disorder at Higher Risk for COVID

On By ModernMedia
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A recent study showed that people with substance use disorders (SUDs) face higher risks for developing COVID and for experiencing serious problems associated with the infection. The study, published in World Psychiatry, examined these risks in fully vaccinated individuals with SUDs.

The study included 579 372 people in the US, of whom 30 183 had a diagnosis of SUD and 549 189 without such a diagnosis) who were fully vaccinated between December 2020 and August 2021 and had not contracted COVID before their vaccinations.

The risk for breakthrough COVID infection in vaccinated people with SUDs ranged from 6.8% for tobacco use disorder to 7.8% for cannabis use disorder, all significantly higher than the 3.6% in the vaccinated non-SUD population. After controlling for demographics (age, gender, ethnicity) and vaccine types (Pfizer, Moderna, Johnson & Johnson), patients with SUDs – with the exception of those with tobacco use disorder – still had higher risks for breakthrough COVID-19 compared with matched individuals without SUDs, with the highest risks for those with cocaine use disorder and cannabis use disorder. 

The higher risk for people with SUDs was found to be largely due to their higher prevalence of comorbidities and adverse socioeconomic determinants of health (such as problems related to education, employment, and housing). However, those with cannabis use disorder, who were younger and had less comorbidities, still had a higher risk for breakthrough infection even matching for these. This could indicate that other variables, such as behavioural factors or adverse effects of cannabis on pulmonary and immune function, could explain some of their higher risk for breakthrough infection.

“In our study, the overall risk of COVID infection among vaccinated SUD patients was low, highlighting the effectiveness and the need for full vaccination in this population,” the authors wrote. “However, our findings document that this group remains a vulnerable one even after vaccination, confirming the importance for vaccinated patients with SUD to continue to take protective preventive measures against the infection.”

Source: Wiley

Categories : COVIDTags :

UK Takes SA off its Red List for Travel

On By ModernMedia
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On Thursday, the UK government announced that South Africa has come of the COVID red list, which has been cut from 54 to just seven.

Brazil and Mexico also come off the red list, which requires travellers to quarantine in an approved hotel at their cost for 10 full days – at a cost of £2285 for one person.  The seven countries remaining on the red list are Panama, Colombia, Venezuela, Peru, Ecuador, Haiti and the Dominican Republic. Vaccinated travellers from South Africa will be treated the same as returning fully-vaccinated UK residents so long as they have not visited a red-list country in the 10 days before arriving in England. All incoming travellers will still complete a passenger locator form.

UK Transport Secretary Grant Shapps said the changes begin on Monday and “mark the next step” in opening travel.

The UK’s travel rues have recently been simplified, with the amber list removed entirely, and advice against holidays changed for 32 countries. Arrivals from 37 more destinations will have their vaccination status certificates recognised, meaning they can avoid more expensive post-arrival testing requirements.

Speaking to the BBC, British expats Matt and Hannah Pirnie, who have lived in South Africa for a decade, said the separation has been difficult.

“It’s been a long pandemic for us. Not seeing family, not being allowed to go back, but more importantly grandparents not being able to come here and see their grandkids. It’s been a long two years,” Matt said.

“First of all when all the aeroplanes stopped initially – that was quite anxiety provoking – and then to be put on the red list for so long has just been quite hard to wrap your head around why,” Hannah adds.

Announcing the latest changes, Mr Shapps said the government was “making it easier for families and loved ones to reunite”. He said that with fewer restrictions “and more people travelling, we can all continue to move safely forward together along our pathway to recovery”.

In addition to the much-abbreviated red list, the government said passengers would soon be able to use a photograph of a lateral flow test as a minimum requirement to verify a negative result, and the more expensive ‘day two’ PCR test was to be replaced with a lateral flow test.

Source: BBC News

Categories : COVIDTags :

6 Tips For Communicating With the Vaccine-hesitant

On By ModernMedia
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Bhekisisa writes that although there are a great number of people who are hesitant but not completely unwilling to take vaccines, there are a number of proven methods to help convince them to get their vaccinations. They offer six helpful tips to improve communication.

Early on during COVID vaccine trials, surveys showed that more than two thirds of adults globally said they would be willing to get on board when a vaccine became available. This was promising, but willingness to get vaccinated doesn’t necessarily translate into actual uptake.

In South Africa at least one poll showed similar results, yet so far just over 32% have actually followed through with getting at least one vaccine dose. There is some good news, though, as there is evidence showing that many people simply need the right approach.

Here are six things to take into account when encouraging hesitant people to get vaccinated.

1. Know the audience
To persuade people to get vaccinated, messages have to be tailored for the intended audience. For example, UK study showed that people seeking to be vaccinated may be receptive to messages public health benefits of vaccination, while those who are vaccine hesitant appear to be more interested about benefits for themselves.

2. Get the word out ASAP
A study in Nature found that the right timing of vaccine messages can increase appointments and subsequent vaccinations. Participants in the US received a text message inviting them to make a vaccination appointment either one day after becoming eligible or eight days after. The earlier text got 1.5 times as many people to make appointments than the later one.

In addition, making the booking also increased uptake, as almost 90% of participants who made a booking after receiving the text kept their appointments – and nearly everyone receiving their first dose got the second.

3. Allay people’s fears
The speed of the COVID vaccine rollout led some to question its safety. Studies from around the world show that fears about ingredients, safety and what many perceive as rushed approval processes deter people from getting vaccinated. This can be compounded by a lack of transparency around vaccine trials and ‘big pharma’ procurement deals can compound doubt and hesitancy.

Though vaccines have abundant evidence on their safety and efficacy, acknowledging that people’s fears are valid is important, as is showing empathy to make hesitant people more open to balanced, evidenced-based messages. At the same time, it is best to be honest about minor side effects, and contextualise how rare the severe side effects are.

The media scare over blood clots in the J&J and AstraZeneca vaccine generated the impression that they were far more frequent than they truly were: which were only one in a million for J&J and 4 to 6 million for AstraZeneca.

4. Name-dropping
Socially influential people can greatly increase vaccine uptake when they encourage others to do so and get one themselves. In 1956, during low uptake of the polio vaccine, Elvis Presley was shown getting his polio shot on TV. This spurred US teenagers to recruit their friends, resulting in a surge of vaccinations. Studies show that even encouragement within peer groups can motivate members to get vaccinated.

5. Ignore holdouts and focus on fence-sitters
A small percentage of people will not take the vaccine under any circumstances, and research shows that it’s virtually impossible to change their minds. About one in eight people are holdouts, while in South Africa the rate is roughly one in 15. While those who are merely hesitant may be persuaded over time, changing the minds of stubbornly resistant individuals is simply a waste of time and money.

6. Understand people’s realities
Historically, vaccination campaigns focused on busting myths and providing evidence-based information about vaccine safety and benefits. Yet opposition to COVID-19 vaccines (and also non-pharmaceutical interventions such as wearing masks and social distancing) seems more strongly rooted in people’s lack of institutional trust, and even a mistrust of government in general when faced with a large-scale epidemic.

There is also a distrust of vaccine arising from historical injustice, such as racism and government experimentation on unknowing individuals. A more recent example is American intelligence services using a vaccination in Pakistan to track down Osama bin Laden, which became something the Taliban used to discredit subsequent vaccination drives.

Source: Bhekisisa

Categories : COVIDTags :

Younger COVID Survivors More Likely to Recover Sense of Smell

On By ModernMedia
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For 4 out of every 5 COVID survivors, those who have lost sense of smell or taste have these return within six months, with those under 40 more likely to recover, according to a new study.

Among 798 respondents to an ongoing survey of people who had COVID and reported a loss of smell or taste, participants who were younger than 40 recovered their sense of smell at a higher rate than those older than 40, according to study results published in the American Journal of Otolaryngology last month.

Evan Reiter, MD, medical director of the Smell and Taste Disorders Center at Virginia Commonwealth University Health and a co-investigator on the study, said the latest data show 4 in 5 participants, regardless of age, regained their smell and taste within six months.

Insights into COVID survivors’ recovery came from symptoms experienced and pre-existing conditions they had. Those with a history of head injury were less likely to recover their sense of smell, as well as those who had shortness of breath during COVID. However, those with nasal congestion had a higher likelihood of smell recovery.

There have been more than 230 million cases of COVID worldwide, according to the World Health Organization. If estimates from the survey reflect populations worldwide, more than 20 million people could have lingering loss of smell or taste more than six months after COVID.

Previous survey results published in April showed 43% of participants reported feeling depressed and 56% reported decreased enjoyment of life in general while experiencing loss of smell or taste. The most common quality-of-life concern was reduced enjoyment of food, with 87% of respondents indicating it was an issue. An inability to smell smoke was the most common safety risk, reported by 45% of those surveyed. Loss of appetite (55%) and unintentional weight loss (37%) continue to pose challenges for patients, Prof said Professor Daniel Coelho, lead author of the study.

Smell training using essential oils could help people trying to recover their sense of smell.

“I continue to recommend that to my patients. It’s low cost and low risk,” Dr Reiter said.

The Clinical Olfactory Working Group, an international group of physicians with a strong research interest in the sense of smell, recommended the method as an option early this year. The group found that smell (olfactory) training could help foster recovery of nerve damage.

“I’d also say potentially it may get people a little bit more tuned into whatever level of function they have left so it might make them more sensitive and better able to use the remaining sensors and neurons that are working,” Dr Reiter said.

Meanwhile, researchers are in the early stages of developing an implant device to restore sense of smell, which began years before the pandemic. The device would behave much like a cochlear implant, which restores hearing for those with hearing loss.

Source: Virginia Commonwealth University

Categories : Cancer COVIDTags :

1 in 7 Cancer Patients Missed Surgery Due to Lockdowns

On By ModernMedia
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One in seven cancer patients around the world have missed out on potentially life-saving operations during COVID lockdowns, according to a new study led by the University of Birmingham.

Planned cancer surgery was impacted by lockdowns regardless of the local COVID rates at that time, especially in lower income countries.
Though lockdowns have protected the public from COVID, they have had collateral impact on care for other patients and health conditions. Researchers in this study showed that lockdowns resulted in significant delays for cancer surgery and potentially more cancer deaths.

Researchers are calling for major global reorganisation during the pandemic recovery to provide protected elective surgical pathways and critical care beds that will allow surgery to continue safely, as well as investment in ‘surge’ capacity for future public health emergencies.

‘Ring-fenced’ intensive care beds would support patients with other health conditions and those with advanced disease (who are most at risk from delays) to undergo timely surgery. Investment in staffing and infrastructure for emergency care would mitigate against disruption of elective services.

The COVIDSurg Collaborative involved 5000 surgeons and anaesthetists around the world working together as part of the to analyse data from the 15 most common solid cancer types in 20 000 patients in 61 countries. The findings were reported in The Lancet Oncology.

The researchers compared cancellations and delays before cancer surgery during lockdowns to those during times with light restrictions. During full lockdowns, one in seven patients (15%) did not receive their planned operation after a median of 5.3 months from diagnosis – all with a COVID related reason for non-operation. However, during light restriction periods, the non-operation rate was very low (0.6%).

Patients awaiting surgery for longer than six weeks during full lockdown were less likely to have their planned cancer surgery. Frail patients, those with advanced cancer, and those waiting surgery in lower-middle income countries were all less likely to have the cancer operation they urgently needed.

Researchers analysed data from adult patients suffering from cancer types including colorectal, oesophageal, gastric, head and neck, thoracic, liver, pancreatic, prostate, bladder, renal, gynaecological, breast, soft-tissue sarcoma, bony sarcoma, and intracranial malignancies.

Lockdowns directly impact hospital procedures and planning, as health systems change to reflect stringent government policies restricting movement. The researchers found that full and moderate lockdowns independently raised the likelihood of non-operation after adjustment for local COVID case notification rates. They hope that this information will help guide future lockdowns and restrictions by governments.

Source: University of Birmingham

Categories : COVIDTags :

Anti-Spike Antibodies Key for Surviving Severe COVID

On By ModernMedia
SARS-CoV-2 viruses (yellow) infecting a human cell. Credit: NIH

In a study of patients with COVID being treated in intensive care units, people mounting only a low antibody response against the SARS-CoV-2 virus had a greater risk of dying. 

Previous studies by the researchers had indicated that levels of SARS-CoV2 viral RNA and antigens in the blood was related to COVID severity.

The study, which is published in the Journal of Internal Medicine, recruited 92 patients severely ill with COVID who were admitted to the ICU. The researchers found that patients with strong antibody responses against the virus had low levels of viral RNA in their blood, especially anti-S (Spike protein) antibodies. Those with poor antibody responses had high viral RNA levels and disseminated viral proteins in the blood, 2.5 times higher than those with strong antibody responses. 

Previous studies have shown that critical COVID patients develop higher titers of SARS-CoV-2 antibodies than those with milder disease, suggesting that antibody response alone is insufficient to avoid severe disease. The findings nonetheless support that critical COVID patients would need to mount a robust anti-S antibody response to survive.

The results could help establish the optimal antibody levels needed for an individual to overcome COVID when critically ill. The study also provided evidence of the importance of antibodies against the Spike protein of SARS-CoV-2 to block the virus’ replication, which are the antibodies induced by vaccination.  

“Our findings support that treatment with exogenous antibodies in COVID should be personalised, reserving this therapy for those patients with absent or low endogenous antibodies levels,” said co–senior author Jesús F. Bermejo-Martin, MD, PhD, of the Instituto de Investigación Biomédica de Salamanca (IBSAL) & CIBERES, in Spain.

Source: Wiley