August 15 2021 COVID-19 report

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Dear Colleagues: Welcome to our Sunday, August 15 report during this eighteenth month of COVID-19 in Ontario. You can find earlier update reports here, including thematic pieces in Doris’ COVID-19 Blog. And, for the many resources RNAO offers on COVID-19, please visit the COVID-19 Portal where you will also find RNAO media hits and releases on the pandemic here. Daily Situational Reports from Ontario’s MOH EOC can be found here. As always, feel free to share this report and links with anyone interested. Scroll down for policy updates and action alerts, as well as RNAO’s upcoming webinars.

In this update we share: (1) RNAO’s response to the latest Ontario government plans; (2) an article reviewing what we know about the more infectious Delta variant; and (3) a second article on what we know about the Delta variant, kids and schools.    

 

 

RNAO welcomes continuing public health restrictions and mandated vaccination for health care workers: More to be done to protect our children and the economy nurses say

RNAO welcomes the news that the Ontario government will mandate vaccines for hospital, long-term care (LTC) and homecare workers, give booster shots to the vulnerable, and halt further reopening. RNAO calls for further urgent action and urges the premier, minister of health, other cabinet ministers, and Ontario’s chief medical officer of health to move quickly and save lives.

The exponential growth of new infections is alarming. Ontario’s seven-day average on August 15 stood at 440. That number last week was 261, and a week before that, the average was 189. Of yesterday’s 511 cases, more than 80% of new cases occurred in unvaccinated or partially vaccinated individuals. The protection afforded by full vaccination is even more striking when considering hospitalization due to COVID-19 (only 12.9% are fully vaccinated) or in ICU (only 1.7% are fully vaccinated). The raging fourth wave is driven primarily by the unvaccinated and the partially vaccinated.

RNAO says the government’s top priority should be to:

  • Expand mandatory vaccination to all health care workers in all health care settings*
  • Implement mandatory vaccination for all teachers and educators in all education settings from daycare all the way to universities*
  • Implement indoor masking in daycare, kindergarten and schools from 2 years old and up*
  • Implement vaccine passports/certificates, mandate their use for access to risky indoor non-essential services – such as indoor concerts, sports events, restaurants, bars and gyms – and adopt a public health framework that protects businesses implementing those measures*

*Unless medical exemption for which accommodation shall be provided through proof of recent testing (48 hours).

RNAO says infection trends in recent days require the need for swift action and a shift in addressing a fourth wave driven by a dangerous variant (see the next article on the Delta variant). The current measures are insufficient and new measures such as those listed above, and those included in RNAO’s call for safe reopening of schools, are urgently required. (See further below an article on the Delta variant, kids and schools).

 

Why is Delta such a worry? It’s more infectious, probably causes more severe disease, and challenges our vaccines

We are in the midst of a fourth wave driven by the Delta variant. This July 5 article from Michael Toole, Professor of International Health at the Burnet Institute in Australia. summarizes what we know about this variant. This article is republished from The Conversation under a Creative Commons license. Read the original article.

 


While Australians may be focused on the havoc the Delta variant is wreaking on our shores, Delta is in fact driving waves of COVID infections all around the world.

With the World Health Organization (WHO) warning Delta will rapidly become the dominant strain, let’s take a look at this variant in a global context.

The rise and rise of Delta

The Delta variant (B.1.617.2) emerged quietly in the Indian state of Maharashtra in October 2020. It barely caused a ripple at a time when India was reporting around 40,000 to 80,000 cases a day, most being the Alpha variant (B.1.1.7) first found in the United Kingdom.

That changed in April when India experienced a massive wave of infections peaking at close to 400,000 daily cases in mid-May. The Delta variant rapidly emerged as the dominant strain in India.

The WHO designated Delta as a variant of concern on May 11, making it the fourth such variant.

The Delta variant rapidly spread around the world and has been identified in at least 98 countries to date. It’s now the dominant strain in countries as diverse as the UK, Russia, Indonesia, Vietnam, Australia and Fiji. And it’s on the rise. [RNAO note: Also in Canada].

In the United States, Delta made up one in five COVID cases in the two weeks up to June 19, compared to just 2.8% in the two weeks up to May 22.

Meanwhile, the most recent Public Health England weekly update reported an increase of 35,204 Delta cases since the previous week. More than 90% of sequenced cases were the Delta variant.

In just two months, Delta has replaced Alpha as the dominant strain of SARS-CoV-2 in the UK. The increase is primarily in younger age groups, a large proportion of whom are unvaccinated.

2 key mutations

Scientists have identified more than 20 mutations in the Delta variant, but two may be crucial in helping it transmit more effectively than earlier strains. This is why early reports from India called it a “double mutant”.

The first is the L452R mutation, which is also found in the Epsilon variant, designated by the WHO as a variant of interest. This mutation increases the spike protein’s ability to bind to human cells, thereby increasing its infectiousness.

Preliminary studies also suggest this mutation may aid the virus in evading the neutralising antibodies produced by both vaccines and previous infection.

The second is a novel T478K mutation. This mutation is located in the region of the SARS-CoV-2 spike protein which interacts with the human ACE2 receptor, which facilitates viral entry into lung cells.

The recently described Delta Plus variant carries the K417N mutation too. This mutation is also found in the Beta variant, against which COVID vaccines may be less effective.

One good thing about the Delta variant is the fact researchers can rapidly track it because its genome contains a marker the previously dominant Alpha variant lacks.

This marker — known as the “S gene target” — can be seen in the results of PCR tests used to detect COVID-19. So researchers can use positive S-target hits as a proxy to quickly map the spread of Delta, without needing to sequence samples fully.

Why is Delta a worry?

The most feared consequences of any variant of concern relate to infectiousness, severity of disease, and immunity conferred by previous infection and vaccines.

WHO estimates Delta is 55% more transmissible than the Alpha variant, which was itself around 50% more transmissible than the original Wuhan virus.

That translates to Delta’s effective reproductive rate (the number of people on average a person with the virus will infect, in the absence of controls such as vaccination) being five or higher. This compares to two to three for the original strain.

There has been some speculation the Delta variant reduces the so-called “serial interval”; the period of time between an index case being infected and their household contacts testing positive. However, in a pre-print study (a study which hasn’t yet been peer-reviewed), researchers in Singapore found the serial interval of household transmission was no shorter for Delta than for previous strains.

One study from Scotland, where the Delta variant is predominating, found Delta cases led to 85% higher hospital admissions than other strains. Most of these cases, however, were unvaccinated.

The same study found two doses of Pfizer offered 92% protection against symptomatic infection for Alpha and 79% for Delta. Protection from the AstraZeneca vaccine was substantial but reduced: 73% for Alpha versus 60% for Delta.

A study by Public Health England found a single dose of either vaccine was only 33% effective against symptomatic disease compared to 50% against the Alpha variant. So having a second dose is extremely important.

In a pre-print article, Moderna revealed their mRNA vaccine protected against Delta infection, although the antibody response was reduced compared to the original strain. This may affect how long immunity lasts.

A global challenge to controlling the pandemic

The Delta variant is more transmissible, probably causes more disease, and current vaccines don’t work as well against it.

WHO warns low-income countries are most vulnerable to Delta as their severe vaccination rates are so low. New cases in Africa increased by 33% over the week to June 29, with COVID-19 deaths jumping 42%.

There has never been a time when accelerating the vaccine rollout across the world has been as urgent as it is now.

WHO chief Tedros Adhanom Gebreyesus has warned that in addition to vaccination, public health measures such as strong surveillance, isolation and clinical care remain key. Further, tackling the Delta variant will require continued mask use, physical distancing and keeping indoor areas well ventilated.The Conversation

 

Is it more infectious? Is it spreading in schools? This is what we know about the Delta variant and kids

This article by four Australian pediatricians summarizes what we know about the Delta variant and schools. It was published July 7 by Margie Danchin, Paediatrician at the Royal Childrens Hospital and Associate Professor and Clinician Scientist, University of Melbourne and MCRI, Murdoch Children's Research Institute; Archana Koirala, Paediatrician and Infectious Diseases Specialist, University of Sydney; Fiona Russell, Senior Principal Research Fellow; paediatrician; infectious diseases epidemiologist; vaccinologist, The University of Melbourne, and Philip Britton, Senior lecturer, Child and Adolescent Health, University of Sydney. This article is republished from The Conversation under a Creative Commons license. Read the original article.

 


The Delta variant is surging across the globe, and the World Health Organization warns it will rapidly become the world’s dominant strain of COVID-19.

Delta is more infectious than the Alpha variant, and preliminary data suggest children and adolescents are at greater risk of becoming infected with this variant, and transmitting it.

Is this true? And with Sydney school students set to begin term 3 remotely, what’s the best way to manage school outbreaks?

Let’s take a look at the evidence.

Delta in children and young people

In the United Kingdom, where the Delta variant has been predominating since May, infections are rising fastest among 17-29-year-olds, who are mostly unvaccinated. Infections are also increasing in younger age groups, but at a lower rate.

[You can see a better view of this graph by clicking here]

Overall, increased transmission among children and young people may partly be due to Delta. But also, in countries like the UK, these age groups are most susceptible to infection because older groups have been largely vaccinated.

While we don’t yet have data on the severity of illness in children associated with the Delta variant specifically, we know with COVID generally, kids are much less likely to become very unwell.

Research from the Murdoch Children’s Research Institute found children clear the virus more quickly than adults, which might go some way to explaining this.

How is Delta affecting transmission in schools?

In 2020, face-to-face learning wasn’t a significant contributor to community transmission in Victoria. Similarly, during the first wave in New South Wales, transmission rates were low in education settings. Concerns children may bring infections home to vulnerable family members weren’t supported by the evidence.

However, the situation is looking somewhat different now with the emergence of new variants and varying levels of vaccine coverage in different countries.

There does appear to be more transmission in schools. In the week ending June 27 there were outbreaks in 11 nursery schools, 78 primary schools, 112 secondary schools and 18 special needs schools in the UK.

While outbreaks in schools are increasing, the vast majority of transmission still occurs in households.

In 2021 in Australia, there have been very few school infections with Delta. In Western Australia, where schools have remained open, an infectious case attended three schools but this didn’t result in any school outbreaks.

During the current NSW outbreak, there have been several schools and early childhood centres with COVID-19 cases, and we have seen one outbreak at a primary school.

Although schools in Australia have largely been spared, transmission rates have been higher than we’ve seen with other variants. Almost all household contacts of cases are becoming infected.

In the recent Melbourne primary school outbreak, our research yet to be published showed that 100% of the household contacts of children who were infected at school went on to test positive.

Fortunately, testing, tracing and isolating were very effective in containing the outbreak, even with the Delta variant.

But these recent school outbreaks highlight why it’s so important adults of all ages, especially parents and teachers, get vaccinated.

Should we vaccinate children?

There are benefits of vaccinating children, particularly teenagers. These include direct protection against the disease, but also reducing transmission to vulnerable adults and enabling continued school attendance.

The risks and benefits need to be carefully calculated in a low transmission setting like Australia. In terms of risks, emerging data suggest the mRNA vaccines Pfizer and Moderna are associated with a very small risk of myocarditis (inflammation of the heart muscle) and pericarditis (inflammation of the heart lining) in young adolescents and adults,