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Health experts warn workers to stay home amid Covid “variant soup” wave

Health experts are warning people to work from home when they can, as the latest Covid wave is expected to peak before Christmas. Since October, cases have steadily been on the rise in Victoria and New South Wales, following a new “variant soup”. Last week, NSW Health changed its Covid-19 risk rating from green to amber, as cases in NSW and Victoria have doubled in just a fortnight. Hassan Vally, an Associate Professor in Epidemiology at Deakin University, said on Monday that new variants XBB and BQ.1 were driving case numbers as they became more dominant. He also said that the new variants were less severe, but more infectious. “We also know these variants don’t seem to be increasing in virulence … The evidence seems to point to they’re inherently less virulent,” he said during an Australian Science Media Centre briefing. Dr Vally said the current wave was expected to make a sharp increase before a sharp decrease by the end of the year, as he urged people to take “preventative measures” to avoid getting sick. “Each wave seems to be having less impact,” Dr Vally said. He said the threat posed by Covid wasn’t over, but emphasised we had entered a stage of living alongside the virus. Last week, health authorities recommended that residents of NSW wear masks indoors and on public transport if social distancing wasn’t available. NSW residents will also now have to wear masks in all areas of hospitals. In the week ending November 17, there were 27,869 people across NSW infected with Covid-19. Health authorities in NSW, Queensland, Western Australia and the ACT have issued similar warnings, strongly recommending a return to wearing masks in public indoor areas and on public transport, but have shied away from reintroducing mandates. Dr Vally said people who were in a position to work from home should do so when they can. “Maybe this is a point also where people, where they have the flexibility, should work from home a little bit more than what may become normal,” he said. Image credits: Getty Images

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Aussies warned of “nightmare variant”

NSW’s chief health officer Kerry Chant has warned that Australia is on the brink of another Covid wave. The health official said that sub-variants BQ. 1 and XBB are well on the way of becoming the dominant strain over BA.5 in Australia Dr Chant said the XBB strain, which recently emerged in Singapore, is ripping through the nation at an alarming rate. Some international experts have described the XBB strain as the “nightmare variant” and the “most vaccine-resistant yet”. “We're starting to see an increase in Covid-19 cases and changes in the variants circulating in NSW, which tells us that we're entering the next Covid wave,” Dr Chant said in a video. “By looking at all the local information we have, and what's happening overseas, we believe Covid cases will rise in the coming weeks.” She asked Aussies to keep up to date with their vaccinations to ensure the protection of the vulnerable. “The protection the NSW community has from vaccination and previous infection continues to reduce the risk of severe illness,” she continued. “However the elderly and those with underlying health conditions continue to be at risk.” Image: ABC

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A new Covid variant has emerged: Can you get it if you’ve had Covid already?

Health authorities have expressed their concern over the spread of a new variant of COVID-19, with NSW Premier Dominic Perrottet saying they would “tailor settings” if needed. A new subvariant of Omicron, called BA.2, has been recorded across the globe and is the dominating strain in at least 18 countries. Currently, the BA.1 Omicron variant remains the top strain in NSW and Victoria, though NSW Health Minister Brad Hazzard said BA.2 could quickly overtake it and cause cases to double within the next four to six weeks. Other states, including Victoria, are expected to follow suit. It comes as both NSW and Victoria recorded a drop in cases on Friday after experiencing 16,288 and 7779 new cases on Thursday. Appearing on Sunrise, Mr Perrottet said that boosters were the best protection against the new variant, and that authorities would “tailor settings” if required. “The best thing we can do is get boosted,” he <a href="https://7news.com.au/news/coronavirus/ba2-omicron-covid-variant-rapidly-sweeping-the-globe-and-could-see-cases-double-in-nsw--c-6013296" target="_blank" rel="noopener">said</a>. “The virus is not going away.” BA.2 explained The Omicron variant of Covid, the dominant version circulating around the world, is made up of several subvariants called BA.1, BA.2, BA.3 and BA.4, with BA.1 and BA.2 being the most common. These two subvariants differ in their genetic sequences, with some studies finding BA.2 has a growth advantage over BA.1. <a href="https://theconversation.com/coronavirus-variants-viral-mutation-and-covid-19-vaccines-the-science-you-need-to-understand-153771" target="_blank" rel="noopener">According to Richard Kuhn</a>, a professor of biological sciences at Purdue University, a variant with a growth advantage is better than the original virus, meaning it can evolve and be “successful” at spreading. In a <a href="https://www.who.int/news/item/22-02-2022-statement-on-omicron-sublineage-ba.2" target="_blank" rel="noopener">statement</a>, the WHO pointed to initial data suggesting BA.2 appears to be more transmissible than BA.1, though the difference between them is less stark than the difference in transmissibility of Omicron BA.1 versus the Delta strain. Can I get BA.2 if I’ve already had Covid? Though studies investigating BA.2 are ongoing, some initial data suggests that people who have been infected with the Omicron variant are protected from reinfection with BA.2 “for the limited period for which data are available”. In a <a href="https://www.medrxiv.org/content/10.1101/2022.02.19.22271112v1" target="_blank" rel="noopener">Danish study</a>, which is yet to be published or peer-reviewed by other scientists, they sequenced samples from 263 people who had been infected with COVID-19 twice between November 11, 2021 and February 11, 2022. Of these, 47 were found to have contracted BA.1 first and BA.2 second, 50 contracted the same variant twice, and 140 contracted BA.2 after they were infected with Delta. Out of those 47 people, the majority were unvaccinated, under the age of 20, and experienced mild symptoms. The WHO’s Technical Advisory Group on SARS-CoV-2 Virus Evolution (TAG-VE) also considered data from South Africa, the UK, and Denmark to assess the severity of disease caused by BA.2, finding that there was no “reported difference” between it and BA.1. Image: Getty Images

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Pfizer booster may offer important protection against Omicron variant

Pfizer has announced that a booster of its COVID-19 vaccine may improve protection against the new Omicron variant of the virus. Pfizer and its partner BioNTech said on Wednesday that while two doses of the vaccine may not be sufficient protection against the Omicron variant, lab tests showed that a booster shot increased people’s levels of antibodies capable of fighting Omicron by 25-fold. For those who have not yet received a booster, two doses should still prevent severe disease or death. Health authorities in Australia, the US and around the world have been urging those eligible to get a third dose as soon as they are able. Dr Mikael Dolsten, Pfizer’s chief scientific officer, told the Associated Press, "Go and get your third boost as soon as possible. This is comforting and a very positive message that we now have a plan that will induce immunity that is likely to protect from infection, symptomatic illness and severe disease from now across the entire winter season." US President Joe Biden said the Pfizer booster news was “very encouraging” although he cautioned, “that’s the lab report. There’s more studies going on.” The findings were announced in a press release and have not yet been subject to scientific review. Pfizer tested blood samples taken a month after a booster had been administered and found that people had levels of Omicron-neutralising antibodies that were similar to amounts proven protective against earlier variants after two doses. It’s important to note that scientists don’t yet know how big a threat the Omicron variant is. Delta remains responsible for most of the current COVID-19 cases around the world, but the Omicron variant carries an unusually large number of mutations, and scientists are working quickly to learn how easily it spreads, whether it causes more serious illness than other variants, and how resistant it might be to vaccines. Image: Jasmin Merdan

Caring

Hospitalisation of children sparks concern over Omicron Covid variant

A South African doctor has expressed concern over the effects of the new Omicron COVID-19 variant on children, saying that more have been hospitalised with moderate to severe symptoms as a result. Dr Rudo Mathivha, head of Intensive Care at Chris Hani Baragwanath hospital, said the number of patients reporting to hospitals has increased exponentially since the new variant took hold. She said the hospital has reportedly admitted around 5-10 children at a time. The doctor also spoke of a 15-year-old with the virus who had died after his condition rapidly deteriorated, as well as of a 17-year-old who had been placed on a ventilator in ICU with coronavirus-related pneumonia. However, it is unclear whether they both had the Omicron variant. “The situation is pretty concerning,” Dr Mathivha told the South African Broadcasting Corporation (SABC). <blockquote class="twitter-tweet"> The omicron variant is sending more children to hospital in South Africa. Infants, who largely only had a mild course of illness with previous variants are now experiencing moderate to severe symptoms. H/T: <a href="https://twitter.com/KatePri35772611?ref_src=twsrc%5Etfw">@KatePri35772611</a> & <a href="https://twitter.com/NjbBari3?ref_src=twsrc%5Etfw">@NjbBari3</a>.<a href="https://t.co/DmdM47dGts">pic.twitter.com/DmdM47dGts</a> — Dr Zoë Hyde (@DrZoeHyde) <a href="https://twitter.com/DrZoeHyde/status/1467377852274266112?ref_src=twsrc%5Etfw">December 5, 2021</a></blockquote> “Because this is not something that we had observed with the first, second and third wave. “... In the past, the children used to get a Covid infection … and it wouldn’t really put them down, it wouldn’t really send them to hospital in big numbers to be admitted. “We are now seeing them coming in with moderate to severe symptoms needing supplemental oxygen, needing supportive therapy, needing to stay in hospital for quite a number of days. “But what really broke my heart yesterday was a 15-year-old previously well child, no illness. Two day history of fever, comes into the hospital, tests positive for Covid and literally deteriorates in front of our eyes and nothing, no supportive therapy that we could do could help him. Dr Mathivha <a rel="noopener" href="https://www.nzherald.co.nz/world/covid-19-omicron-outbreak-children-hospitalised-with-moderate-to-severe-symptoms/QCNS4VJU3H2WEN3UOJU5PEZXYM/" target="_blank">said</a> the boy was the first “child who had no comorbidities, and nothing existing before” who had died of Covid that she was aware of. <blockquote class="twitter-tweet"> Stark warning from experienced clinician at the front line. Hospitals are not made to handle mass paediatric casualties of the toddler age group. Not only in South Africa… anywhere… <a href="https://t.co/RkrF0jbaJs">pic.twitter.com/RkrF0jbaJs</a> — #MasksInSchools Dr Noor Bari (@NjbBari3) <a href="https://twitter.com/NjbBari3/status/1467300490790592519?ref_src=twsrc%5Etfw">December 5, 2021</a></blockquote> She also warned that the hospital may not be able to accommodate any more children soon, describing it as a “major problem” for the hospital to face. “Our hospitals were not built to house a lot of children. Because naturally children do not get that sick in multitude,” she explained. “We will not be able to accommodate them, and I’m not saying this to make people panic. “I am saying this to say, all these preventive measures we take to interrupt the transmission of Covid let them be applied to the children as well.” As South Africa faces its fourth wave of the virus, children remain ineligible for vaccination. The South African Government said the new variant of COVID-19 has been disproportionately affecting children under five, while experts rubbish the idea that the variant is “mild”. “The incidence in those under five is now second highest, second only to those over 60,” government advisor Waasila Jassat told reporters in Johannesburg. She said there has been “quite a sharp increase” in hospital admissions “across all groups but particularly in the under five” demographic. Though the Omicron variant was first detected in Botswana, the neighbouring country of South Africa has become the epicentre of the strain, with the city of Tshwane, in the Gauteng province, becoming one of the worst affected regions. An analysis by South Africa’s National Institute for Communicable Diseases (NICD) has found a recent surge in toddlers being admitted to hospital due to Covid. Dr Waasila Jassat, from the NICD, said young children seemed to be “more at risk”, but it was unclear whether the surge in admissions was linked to Omicron. “When you look at the numbers of admission by age, what we normally see is a large number of admissions in older people,” Dr Jassat said during a media briefing held by the Department of Health. “But in this early resurgence in Tshwane, we are seeing most admissions in the 0-2 age group. And we are seeing a large number of admissions in the middle ages, sort of around 28 to 38.” Dr Jassat noted that the trend could be due to children under 12 still being unvaccinated, and because parents were more concerned about the new variant, making them more likely to take their children to hospital at the first signs of illness. “The very young children have an immature immune system and they are also not vaccinated, so they are more at risk.” Image: Getty Images

News

Travel bans aren’t the answer to stopping new COVID variant Omicron

There is global concern and widespread alarm at the discovery of SARS-CoV-2 variant B.1.1.529, which the World Health Organization (WHO) has called Omicron. The <a href="https://www.who.int/news/item/26-11-2021-classification-of-omicron-(b.1.1.529)-sars-cov-2-variant-of-concern">WHO classified Omicron</a> as a “variant of concern” because it has a wide range of mutations. This suggests vaccines and treatments could be less effective. Although early days, Omicron appears to be able to reinfect people more easily than other strains. Australia has followed other countries and regions – including the United States, Canada, United Kingdom and the European Union – and <a href="https://www.abc.net.au/news/2021-11-27/new-quarantine-rules-omicron-covid-variant-australia/100656016">banned travellers</a> from nine southern African countries. Australians <a href="https://www.abc.net.au/news/2021-11-27/new-quarantine-rules-omicron-covid-variant-australia/100656016">seeking to return home from southern Africa</a> will still be able to do so. But they will enter hotel quarantine and be tested. Those who have returned from the nine countries – South Africa, Namibia, Zimbabwe, Botswana, Lesotho, Eswatini, the Seychelles, Malawi and Mozambique – in the past 14 days will have to isolate. But Omicron has already been detected in other regions, including the UK, Germany, Israel, Hong Kong and Belgium. So while a travel ban on southern African countries may slow the spread and buy limited time, it’s unlikely to stop it. As the Australian government and others act to protect their own citizens, this should be accompanied by additional resources to support countries in southern Africa and elsewhere that take prompt action. <h2>When was Omicron detected?</h2> The variant was identified on November 22 in South Africa, from a sample collected from a patient on <a href="https://www.who.int/news/item/26-11-2021-classification-of-omicron-(b.1.1.529)-sars-cov-2-variant-of-concern">November 9</a>. South African virologists took prompt action, conferred with colleagues through the <a href="https://www.ngs-sa.org/ngs-sa_network_for_genomic_surveillance_south_africa/">Network of Genomic Surveillance in South Africa</a>, liaised with government, and notified the World Health Organization on November 24. This is in keeping with the <a href="https://www.who.int/health-topics/international-health-regulations#tab=tab_1">International Health Regulations</a> that guide how countries should respond. The behaviour of this new variant is still unclear. Some have claimed the rate of growth of Omicron infections, which reflects its transmissibility, may be even higher than those of the Delta variant. This “growth advantage” is yet to be proven but is concerning. <h2>‘Kneejerk’ response vs WHO recommendations</h2> African scientists and politicians <a href="https://www.theguardian.com/world/2021/nov/26/south-africa-b11529-covid-variant-vaccination">have been disappointed</a> in what they see as a “kneejerk” response from countries imposing travel bans. They argue the bans will have significant negative effects for the South African economy, which traditionally welcomes global tourists over the summer year-end period. They note it is still unclear whether the new variant originated in South Africa, even if it was first identified there. As Omicron has already been detected in several other countries, it may already be circulating in regions not included in the travel bans. Travel bans on countries detecting new variants, and the subsequent economic costs, may also act as a disincentive for countries to reveal variants of concern in future. The WHO <a href="https://www.who.int/news-room/articles-detail/updated-who-recommendations-for-international-traffic-in-relation-to-covid-19-outbreak">does not generally recommend</a> flight bans or other forms of travel embargoes. Instead, it argues interventions of proven value should be prioritised: vaccination, hand hygiene, physical distancing, well-fitted masks, and good ventilation. In response to variants of concern, the WHO calls on all countries to enhance surveillance and sequencing, report initial cases or clusters, and undertake investigations to improve understanding of the variant’s behaviour. Omicron must be taken seriously. Its features are worrying, but there are large gaps in our current knowledge. While further analyses are undertaken, the variant should be controlled with testing, tracing, isolation, applying known public health measures, and ongoing surveillance. <h2>What can wealthier countries do to help?</h2> Wealthy countries such as Australia should support African nations and others to share early alerts of potentially serious communicable disease threats, and help mitigate these threats. As the <a href="https://theindependentpanel.org/mainreport/">Independent Panel for Pandemic Preparedness and Response</a> noted in May: <blockquote> […] public health actors only see downsides from drawing attention to an outbreak that has the potential to spread. </blockquote> The panel recommended creating incentives to reward early response action. This could include support to: <ul> <li>establish research and educational partnerships</li> <li>strengthen health systems and communicable disease surveillance</li> <li>greatly improve vaccine availability, distribution, and equity</li> <li>consider financial compensation, through some form of solidarity fund against pandemic risk.</li> </ul> <h2>Boosting vaccine coverage is key</h2> Vaccines remain the mainstay of protection against the most severe effects of COVID-19. It’s unclear how effective vaccines will be against Omicron, but some degree of protection is presumed likely. Pfizer has also indicated it could develop an effective vaccine against a new variant such as <a href="https://www.independent.co.uk/news/health/omicron-variant-covid-vaccine-tweaked-b1965155.html">Omicron within 100 days or so</a>. COVID’s persistence is partly attributable to patchy immunisation coverage across many parts of the world, notably those least developed. South Africa itself is better off than most countries on the continent, yet only <a href="https://ourworldindata.org/covid-vaccinations">24% of the adult population are currently fully vaccinated</a>. For the whole of Africa, this drops to only 7.2%. Greater global support is urgently needed to boost these vaccination rates. African institutions and leaders, supported by global health and vaccine experts, have argued for mRNA vaccine manufacturing facilities on the African continent. These would prioritise regional populations, overcome supply-chain problems, and respond in real time to emerging disease threats. Yet developing nations face <a href="https://www.theguardian.com/australia-news/2021/nov/25/australian-government-trying-to-have-it-both-ways-on-covid-vaccine-ip-waiver">significant barriers</a> to obtaining intellectual property around COVID-19 vaccine development and production. While there is still much to learn about the behaviour and impact of Omicron, the global community must demonstrate and commit real support to countries that do the right thing by promptly and transparently sharing information.<img style="border: none !important; box-shadow: none !important; margin: 0 !important; max-height: 1px !important; max-width: 1px !important; min-height: 1px !important; min-width: 1px !important; opacity: 0 !important; outline: none !important; padding: 0 !important; text-shadow: none !important;" src="https://counter.theconversation.com/content/172736/count.gif?distributor=republish-lightbox-basic" alt="The Conversation" width="1" height="1" /> <a href="https://theconversation.com/profiles/anthony-zwi-144612">Anthony Zwi</a>, Professor of Global Health and Development, <a href="https://theconversation.com/institutions/unsw-1414">UNSW</a> This article is republished from <a href="https://theconversation.com">The Conversation</a> under a Creative Commons license. Read the <a href="https://theconversation.com/travel-bans-arent-the-answer-to-stopping-new-covid-variant-omicron-172736">original article</a>. Image: Shuttershock

International Travel

Delta variant more infectious than Wuhan strain, study finds

A new study from the UK has found that the Delta strain of COVID-19 is eight times less sensitive to vaccine antibodies than the original Wuhan strain. The study also found that changes to the spike protein in the Delta variant improved its ability to replicate and enter cells, in comparison to the Kappa variant. The authors say this might explain how the Delta strain has become the most dominant variation of the disease. The study, published in the journal <a rel="noopener" href="https://www.nature.com/articles/s41586-021-03944-y" target="_blank">Nature</a>, compared the mutated Delta variant against the mutated Wuhan-1 variant which was used to develop the vaccines. The team, led by Ravindra Gupta, a professor of clinical microbiology at the Cambridge Institute of Therapeutic Immunology and Infectious Disease, also analysed infections of 130 healthcare workers across three hospitals in Delhi, India, over six weeks. Though each of the workers studied had received both doses of the AstraZeneca vaccine, the researchers found that the vaccine was less effective against the Delta variant than other variants. “By combining lab-based experiments and epidemiology of vaccine breakthrough infections, we’ve shown that the Delta variant is better at replicating and spreading than other commonly-observed variants,” Professor Gupta <a rel="noopener" href="https://www.cam.ac.uk/research/news/spread-of-delta-sars-cov-2-variant-driven-by-combination-of-immune-escape-and-increased-infectivity" target="_blank">said</a>. Joint senior author Dr Patha Rakshit from the National Centre for Disease Control, Delhi, India, said: “The Delta variant has spread so widely to become the dominant variants worldwide because it is faster to spread and better at infecting individuals than most other variants we’ve seen. “It is also better at getting around existing immunity - either through previous exposure to the virus or vaccination - though the risk of moderate to severe disease is reduced in such cases.” Professor Anurag Agrawal from the CSIR Institute of Genomics and Integrative Biology, Delhi, India and joint senior author said the infection of healthcare workers with the Delta variant could have severe consequences. “Although they themselves may only exhibit mild COVID, they risk infecting individuals who have suboptimal immune responses to vaccination due to underlying health conditions - and these patients could then be at risk of severe disease,” Professor Agrawal said. With their findings, Gupta and his colleagues say we will need to develop strategies for boosting the effectiveness of vaccines against variants of COVID-19. “We urgently need to consider ways of boosting vaccine responses against variants among healthcare workers,” Professor Agrawal added. “[This research] also suggests infection control measures will need to continue in the post-vaccine era.”

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‘Most mutative’ COVID variant now located

A US expert has told Karl Stefanovic on the Today show about a new COVID variant which is the ‘most mutative’ virus so far and he said “unless you are triple-vaxxed” you’re not protected.” US expert Dr Eric Feigl-Ding, warned two doses of vaccine may not be enough protection against the C.1.2 COVID strain, adding this virus is mutating “so much faster than we expected,” that three doses of vaccine will be required to protect against it. The strain was first identified by scientists in South Africa in May and has since been found in England, China, the Democratic Republic of the Congo, Mauritius, Portugal Switzerland and even New Zealand. The C.1.2-strain has almost double the mutation rate Scientists have reported the C.1.2 strain in South Africa has a mutation rate of 41.8 mutations per year, almost double the current global mutation rate seen in any other variant of concern so far. The C.1.2-strain has yet to make its way to Australia, but this new strain has experts on edge, including Dr Eric Feigl-Ding, an epidemiologist and Senior Fellow at the Federation of American Scientists in Washington DC. “It's got lots of troubling mutations and it's the most mutative of all variants,” he told the Today show this week. “It's the most genetically distanced from the Wuhan 1.0 virus. Whether or not it's the next big thing, it's not necessarily that, it's the fact that the virus is mutating so much faster than we expected.” An elimination strategy is required Dr Feigl-Ding, who is a member of the World Economic Forum's Global Shapers program, a Soros Fellowship recipient and a former Democratic Party candidate, said he advocated a COVID elimination strategy. “We can't just keep boosting the vaccines,” he said. “We have to basically stop the transmission worldwide because the more bodies we give the virus, the more practice chances the virus will eventually adapt and become even more evasive or contagious.” He also warned two doses of the vaccine may not be enough with Israel already introducing third booster shots. “Unless you're triple vaxxed, you're not considered fully vaxxed. And that approach as much as it sucks, is the reality that we’re faced with – with these new variants,” Dr Feigl-Ding said. Image: Today Show

News

How much does COVID-19 weigh?

The total mass of COVID-19 globally is currently between 100g and 10kg, according to an estimate <a href="https://www.pnas.org/content/118/25/e2024815118">recently published</a> by Ron Milo of the Weizmann Institute of Science and his colleagues. The article also details exactly how the team calculated the estimate. Using the typical viral load of tissues and fluids in the body during the peak of an infection, the researchers estimated that an individual would carry between 1-100 billion viral particles, with a total mass of between 1 and 100 micrograms (between 0.0001 and 0.1 milligrams) during peak infection. The team then calculated the global mass of the virus by multiplying the viral load by the number of cases globally. The total number of viral particles globally was also calculated, with the researchers estimating that there have been between one hundred quadrillion and ten quintillion viral particles at any given time, assuming there has been between 1 million to 10 million people infected at close to peak infection over the course of the pandemic. Why this matters It was also noted that, for every person infected with COVID-19, the virus particles enter cells and replicate between three and seven times. Each of these replications can also introduce mutations, though not all of them will result in new variants of the virus. This allows researchers to calculate an estimated rate of the formation of new genetic variants and form a better understanding of how many cells in different areas of the body can become infected.

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We’re seeing more casual COVID transmission. But is that because of the variant or better case tracking?

Victoria’s lockdown <a href="https://www.abc.net.au/news/2021-06-02/new-covid-cases-recorded-in-victoria-lockdown-decision/100183416">is to be extended</a> for another week to get on top of the growing number of community cases, which now stands at 60. But questions remain about what’s behind some of these cases. Victoria’s COVID-19 testing commander Jeroen Weimar <a href="https://www.9news.com.au/national/health-authorities-concerned-over-victorias-strangertostranger-covid-local-transmission/7ad661c9-da7a-4555-a38a-c3d7606a5ebd">said yesterday</a> in about four or five cases, the virus was transmitted after only “fleeting contact”. Today, <a href="https://www.abc.net.au/news/2021-06-02/new-covid-cases-recorded-in-victoria-lockdown-decision/100183416">we heard from</a> Victoria’s Chief Health Officer Brett Sutton about <a href="https://7news.com.au/lifestyle/health-wellbeing/victoria-chief-health-officer-brett-sutton-concerning-suspicion-about-fleeting-transmission-c-2994447">one case suspected</a> to have been infected when visiting a site some two hours after an infectious person had left. The source case had been there for some time, and it was described as a poorly ventilated space. Nonetheless, this is consistent with the <a href="https://theconversation.com/the-pressure-is-on-for-australia-to-accept-the-coronavirus-really-can-spread-in-the-air-we-breathe-160641">aerosol transmission</a> we have become increasingly concerned about, and perhaps this is the first documentation of this outside hotel quarantine. Today we also heard that health authorities have reported about 10% of cases are linked with more casual exposures, including at “tier two” sites (Victoria describes exposure sites according to risk, with a tier one site being the most risky). So is it the virus, or more focused efforts in tracking cases, that’s led us to finding such casual exposures? Is it the virus? Despite today’s news, people are not more likely now to get infected by brushing past someone on the street. In the vast majority of cases, people have become infected by very close contacts, or at certain “<a href="https://www.coronavirus.vic.gov.au/exposure-sites">tier one</a>” exposure sites when there at the same time as a known case. There is <a href="https://theconversation.com/whats-the-indian-variant-responsible-for-victorias-outbreak-and-how-effective-are-vaccines-against-it-161574">evidence</a> the variant associated with India is more infectious. This particular lineage of the Indian variant B.1.617.1, however, may not be as <a href="https://www.gov.uk/government/publications/covid-19-variants-genomically-confirmed-case-numbers/variants-distribution-of-cases-data">infectious</a> as other lineages. It reinforces how important it is that outbreaks are contained as early as possible where this increased risk of spread is still manageable. On average, with variants of concern like the one currently circulating in Victoria, a case might infect 15% of household contacts instead of 10% seen in 2020. When new case numbers are high later in an outbreak, this difference in transmission translates to much bigger jumps in case numbers. The way the virus spreads in clusters has also not changed, with some cases not passing the virus on, while a small number pass it on to many. If this strain of the virus were vastly more transmissible than the original strain, we’d expect to see many cases. This strain has been in our community for a month now, undetected and running free for more than two weeks. There would be many more than 60 cases if this were true. We’re also better at tracking cases The main thing that’s changed since Victoria’s second wave last year is that we have forensic analysis of every case and we’re better at finding casual links between cases. We’re now publishing lists of venues with exposure times and more people are coming forward for testing than at the peak of Victoria’s second wave. We also have check-in data for many venues. This results in more reliable measures of both the total spread and routes of virus transmission, than in the second wave, or any community outbreak of this size. Transmission associated with more casual exposures would have been much more likely to be missed before. Even if these cases were picked up, they might have been counted among the “mystery cases” that comprised 18% of all cases in 2020. We didn’t know where these cases were infected as there were no apparent links between them and known cases. We are doing much better this time with only three transmission events that not yet fully understood. How about this ‘fleeting contact’? The four or five cases Weimar mentioned yesterday relate to a range of indoor exposure sites including a display home, a Telstra shop, local grocery stores, and a shopping strip. This is where people may have been in direct contact with a case, but where no definitive exposure event is documented, there is no check-in and people don’t know each other. So from what we know so far, there’s been a crossover between when most cases were present and where their contacts became infected. And 90% of these are in the settings we know are high transmission risk — households and workplaces in particular, where there is extended and repeated indoor contact. The more casual contacts described yesterday, in a display home or at the Telstra shop, there might have been some overlap with a case in a small enclosed area for sufficient time to receive an infecting dose. A further example Sutton provided today was an infection that started with someone sitting in the same outdoor area as a case at a hotel bistro. We know there is less risk in outdoor settings generally, but on a still autumn day, we now know this is all it takes. Now, as we have transmission in the beer garden, all those nearby will be recategorised as primary close contacts and asked to quarantine for a full 14 days, even if they have returned a negative test. Better to be safe than sorry. That’s why it’s so important to check in with a QR code. You don’t always know the name of the person who’s standing (or sitting) next to you. It is also why check-ins will now be required at more retail and public venues across the state. Being able to identify contacts in these settings will remove some of the fear associate with this more casual spread. So what are we to make of this? This latest news reinforces the importance of QR codes and checking in. You never know who you’re standing next to in a long queue while shopping. Extending our QR codes into further settings whether retail, grocery stores or display homes, which we now know are a risk, is a good move. The message remains the same, get tested if you have symptoms or when directed to by public health officials, and isolate when necessary. In particular, keep an eye on those exposure sites, even if you only dropped in to grab a coffee. But we shouldn’t be overly concerned about COVID-19 spread by “fleeting contact”. The precautions we all know (hygiene, distancing and masks) still work and are our best forms of protection.<img style="border: none !important; box-shadow: none !important; margin: 0 !important; max-height: 1px !important; max-width: 1px !important; min-height: 1px !important; min-width: 1px !important; opacity: 0 !important; outline: none !important; padding: 0 !important; text-shadow: none !important;" src="https://counter.theconversation.com/content/161979/count.gif?distributor=republish-lightbox-basic" alt="The Conversation" width="1" height="1" /> <a href="https://theconversation.com/profiles/catherine-bennett-1129281">Catherine Bennett</a>, Chair in Epidemiology, <a href="https://theconversation.com/institutions/deakin-university-757">Deakin University</a> This article is republished from <a rel="noopener" href="https://theconversation.com" target="_blank">The Conversation</a> under a Creative Commons license. Read the <a rel="noopener" href="https://theconversation.com/were-seeing-more-casual-covid-transmission-but-is-that-because-of-the-variant-or-better-case-tracking-161979" target="_blank">original article</a>.

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New fears as COVID-19 UK variant mutates again

<div class="post_body_wrapper"> <div class="post_body"> <div class="body_text redactor-styles redactor-in"> Scientists have warned that the highly contagious UK variant of COVID-19 has mutated again and may give the virus the ability to evade the immune system. Public Health England reported that some sample tests detected genomes with the E484K mutation, which has been seen in the highly contagious South African and Brazilian variants of COVID-19. Calum Semple told BBC radio that this mutation is of "most concern" and seems to have developed spontaneously in the UK varient. “The mutation of most concern, which we call E484K, has also occurred spontaneously in the new Kent strain in parts of the country too,” said Professor Semple, a member of the Scientific Advisory Group for Emergencies (SAGE). UK Health Secretary Matt Hancock said that a further 11 cases of mutations of concern had been identified in Bristol and 32 in Liverpool. Authorities in parts of London, the West Midlands, East, South East and North West England have started offering door-to-door and mobile COVID-19 testing in a push to test 80,000 people for the mutation. “In all these areas it is imperative that people must stay at home and only leave home where it is absolutely essential,” Hancock said. Testing is being offered to everyone in these areas over the age of 16, even if they have had the vaccine. “The message is more important than ever to stay at home, maintain social distancing and get tested," Hancock explained. “We must all keep at it, we’ve sacrificed so much,” he added, warning of “difficult weeks ahead”. </div> </div> </div>

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