Delta variant

Masks Have Made No Meaningful Difference to Delta – Oxford Professor

Professor Jim Naismith, Director of the Rosalind Franklin Institute and Professor of Structural Biology at the University of Oxford, has pointed out that, despite England dropping its mask mandate in July while Scotland kept its one in force, there is no evidence of this policy making any difference in the two countries’ infection rates. He writes:

The ONS survey results on prevalence shows that the Scottish and English approach to masking, although formally different since July, has made no meaningful difference to Delta. In both countries very high levels of prevalence have continued for months. Thus the new changes announced are unlikely to have much of an impact if Omicron does indeed spread rapidly.

You can see the ONS graphs below for yourself, and he’s right. Yet the Government has re-imposed masks in schools, shops and on public transport, despite there being no evidence that they make any significant impact on the spread of disease.

Why Are Sweden and India Not Seeing a Covid Surge?

Why are some countries surging this autumn but others aren’t, at least not yet? Much of Europe is now seeing sharp rises in reported infections. In some it appears to be a delayed Delta surge, but in others like France, Netherlands, Norway and Finland it comes after an earlier summer Delta ripple that looked like it had gone away. Yet India, which had (quite literally) the mother of Delta surges, has not seen any new rise despite only 29% of its population being double-vaccinated, and despite the festivals of Diwali and Durga Puja, widely warned about as a transmission risk, taking place in the autumn.

Sweden, meanwhile, has somehow so far managed to avoid Delta surges altogether, after being hit relatively hard in spring 2020 and winter 2020-21. The country famously imposed only light restrictions (no stay-at-home orders, school or business closures or mask mandates at any point). Similarly, few restrictions were imposed in India in 2021, and there is also doubt about how far Indian citizens have followed any restrictions that were brought in; in any case, high population antibody rates were subsequently reported. Are India and Sweden benefitting from a more robust immunity owing to greater exposure prior to this autumn? What happens this winter will help to clarify this question.

The U.K. meanwhile is experiencing a strangely drawn-out Delta epidemic. Beginning in June, it has now been simmering away at around about the same level for five months, neither exploding as the models predicted, nor dropping off again back to low levels, as earlier waves have done.

Covid Infections Surge in Europe

A late autumn surge in reported Covid infections is underway in Europe, with spikes in Austria, Netherlands, Denmark, Germany, Switzerland and Norway, and the possible beginnings of one in France, Portugal and Italy. This is despite high vaccine coverage and the heavy use of vaccine passports in most of these countries including Germany, Netherlands, Austria, Switzerland, Italy and France.

Some of this is at least partly a result of ramping up testing, especially in Austria and Denmark.

Denmark’s positive test rate is currently flat (see below). This is despite the country declaring the pandemic over and abandoning vaccine passports in September. However, due to the climbing reported infection rate, the country’s Parliament is now said to be preparing to return to a state of emergency and reactivate the vaccine pass scheme, despite the rise being so far largely an artefact of increased testing.

Elsewhere, however, the positive rate is also rising, suggesting real Covid and not just a testing artefact.

China’s Extreme Zero-Covid Policies Have Not Shielded It From Its Largest Outbreak Since Wuhan

The Chinese Government has declared that the nation is going through a severe outbreak of the Delta variant, with the epidemic reaching 20 out of 31 provinces. This situation has developed in spite of China’s extreme zero-Covid measures, with the Government now telling members of the public to stock up on food supplies in preparation for further restrictions. The MailOnline has more.

Cases were concentrated in the country’s northern regions of Gansu, Heilongjiang and Inner Mongolia.  

The National Health Commission confirmed on Monday 65 new local symptomatic cases for Sunday, up from 50 a day earlier and the highest daily count since August 9th at the peak of China’s last major outbreak. 

Most of the local cases were found in Dalian, in the northeastern province of Liaoning, where nine infections were recorded on Wednesday. 

And reports from the Sichuan provincial capital said dozens of people had scaled fences and trekked through bushes to avoid being tested for Covid.

It came after the capital was sealed off by authorities for mandatory testing after a person who had visited the city became infected. Police said they had not yet verified the reports or arrested anyone and were investigating.  

The spread and rise in Covid infections comes despite the Chinese Government enforcing tighter curbs to contain the cases.

Henan province’s Communist Party Secretary Lou Yangsheng said on Monday the region would “contain and kill” its outbreak in one week. 

The vow came after Henan recorded the largest single-day rise in local infections of the present outbreak with three on Saturday and 18 on Sunday. 

Lou said officials would improve contact tracing systems and increase monitoring of close contacts and potential cases. He added lockdowns would be implemented and expanded as necessary.  

National authorities also said on Saturday the country would continue to pursue a zero-Covid strategy. 

One expert last week insisted the current outbreak will be contained “within a month”.

Zhong Nanshan, a leading expert in China’s respiratory disease research, told China Global Television Network that China will continue with its zero-transmission policy against Covid, because the global Covid fatality rate of 2% is too high.

Worth reading in full.

Vaccination Has No Impact on Household Transmission of the Delta Variant, Study Finds

According to a recent study published in the Lancet, those who have received a Covid vaccine are just as likely as the unvaccinated to transmit the Delta variant within a household setting. In addition, researchers uncovered that both the unvaccinated and the vaccinated had a similar viral load of the disease when infected, with 25% of vaccinated household contacts contracting the disease. The Hill has the story.

According to the study published in the Lancet Infectious Diseases journal, people who contracted Covid had a similar viral load regardless of whether they had been vaccinated. The study further found that 25% of vaccinated household contacts contracted Covid while 38% of unvaccinated individuals were diagnosed with the disease.

Researchers examined 621 symptomatic participants in the United Kingdom over a year.

“Although vaccines remain highly effective at preventing severe disease and deaths from Covid, our findings suggest that vaccination is not sufficient to prevent transmission of the Delta variant in household settings with prolonged exposures”, the study said.

In contrast, researchers noted that the vaccination was more effective at curbing transmission of the Alpha variant within the household, at between 40 and 50%. 

“Increasing population immunity via booster programmes and vaccination of teenagers will help to increase the currently limited effect of vaccination on transmission, but our analysis suggests that direct protection of individuals at risk of severe outcomes, via vaccination and non-pharmacological interventions, will remain central to containing the burden of disease caused by the Delta variant”, the researchers wrote.

Worth reading in full.

No Evidence New Delta Sub-Variant AY.4.2 is Anything to Worry About

There’s a new variant in town. Or rather, a sub-variant – AY.4.2, an offshoot of the Delta variant, said by some scientists to be up to 10-15% more transmissible. As of the end of September it made up around 6% of new cases and is on an upward trajectory.

Variants detected in England (Wellcome Sanger Institute)

However, there’s no reason to panic – and, for a change, that’s the message coming from the top. The Prime Minister’s official spokesman said: “There’s no evidence to suggest that this variant… the AY.4.2 one… is more easily spread. There’s no evidence for that…”

Francois Balloux, Director of the University College London Genetics Institute, said while the variant is “likely to be up to 10% more transmissible”, it is not comparable to Delta when it arrived in the U.K, which was at least 50% more infectious than Alpha.

Professor Balloux played down the likely impact of the increased transmissibility on infections, adding:

Nailed It! Daily Sceptic Accurately Predicts the Delta Surge in Seven Countries

Two months ago Anthony Brookes, Professor of Genomics and Health Data Science at the University of Leicester, wrote an important piece for the Daily Sceptic in which he assembled the “Covid jigsaw pieces into a complete pandemic picture”.

To recap, this was his summary of his argument:

  • A series of SARS-CoV-2 variants have arisen, many of which possessed a transient selective advantage that led to a wave of infection that peaked some three-to-four months later. Several such variants have spread globally, though different successful variants have arisen simultaneously in a number of countries. The result is a three-to-four month wave pattern per country, which is also apparent globally.
  • Seasonality affects variant transmissibility. Colder seasons accelerate the growth and increase the size of waves, but the continually changing environment may also differentially affect the relative transmissibility of competing variants (i.e., negatively as well as positively), thereby helping to terminate previously dominant variants and promote the growth of new ones. 
  • Overall there is a minimal positive impact from quarantine policy, isolation requirements, Test and Trace regimes, social distancing, masking or other non-pharmaceutical interventions. Initially, these were the only tools in the tool-box of interventionist politicians and scientists. At best they slightly delayed the inevitable, but they also caused considerable collateral harms.  
  • Immunity created by SARS-CoV-2 infection, layered on top of pre-existing immunity due to cross-immunity to other coronaviruses, provides good protection against infection, severe disease/death, and being infectious. Immunity created by vaccination also helps protect against serious disease and death, but does little or nothing to provide protection against infection or being infectious (which completely negates the case for vaccine ID cards). 
  • Population immunity stems mainly from natural infections, with vaccines adding only slightly to this (and only in recent months). Population immunity is created by societal waves of infection and is somewhat variant-specific. An emerging new variant is able to infect (or re-infect) some fraction of individuals and this serves to top up and broaden the scope of our population immunity to also protect against the new variant. 
  • This empirical and data-driven understanding of the pandemic allows us to make predictions. Such predictions don’t look good for some of the U.K.’s new Green List countries. But in these and all other places the ongoing arms-race between viral mutations and growing human immunity will always eventually be won by the human immune system. The virus then becomes a low-level endemic pathogen in equilibrium with its human host species. If this were not the case all humans would have been wiped out by viruses eons ago!

In the piece he made some very specific predictions about what would happen over the following months, and we’re now in a position to see how close he got to the target. He wrote:

With an essentially complete Covid jigsaw picture now assembled using an empirical data-driven approach, we can offer up some testable predictions. The first is that current Delta waves unfolding in different countries will reach natural peaks around three-to-four months after this variant arrived in each location. For example, considering countries recently added to the U.K.’s Green List, we would expect: Slovenia, Slovakia and Romania (where Delta arrived little more than one month ago) will see their nascent summer waves grow further and peak in about two months’ time; Latvia (where Delta has only just arrived) will face a multi-month wave starting very soon; and Austria, Germany and Norway (where Delta has already been present for several months) will likely see their summer waves peak around the end of August. NPIs will do little to change this, and neither will vaccines (see Israel for evidence of this).

So the specific predictions were:

  • Reported cases in Slovenia, Slovakia and Romania peaking around about now.
  • Latvia to currently be on the up-slope.
  • Germany, Austria and Norway to peak around the end of August.

Let’s have a look.

India Confounds the Modellers

What happened to India’s summer and autumn waves? After suffering a large surge with the emergent Indian variant (i.e., Delta) in the spring, India has defied modellers’ predictions by remaining very quiet since.

In August, Rajib Dasgupta, Chair of the Centre of Social Medicine and Community Health at Jawaharlal Nehru University, wrote for the Conversation about the “likely” imminent new autumn surge.

With about 40,000 cases and 400 deaths each day as of mid August, a new uptick is likely in the cards. The Indian states experiencing most of these new cases are those with relatively lower sero-prevalence, ranging between 50% and 70%. The 400 million sero-negative pool – that is people who have not been infected or had the vaccine – continues to be a large vulnerable group.

Forecasting by modellers indicates a third wave beginning in August and peaking at 100,000 to 150,000 infections a day by October. An alternative projection expects the peak in cases going until November.

It’s October now and the reality, of course, is a low level of infections since June and no new surge throughout summer and autumn so far. Below is the graph showing the predictions from the modelling of Mathukumalli Vidyasagar and Manindra Agrawal of the Indian Institute of Technology that Rajib Dasgupta cites above. I have added in the line of actual ‘cases’, which shows that they have trended well below the ‘optimistic’ scenario since the moment the prediction was made.

The Role of Variants in Driving Surges is Good News for Sceptics

As an addendum to my piece yesterday on the evidence for variants driving Covid surges, a comparison between India and neighbouring Bangladesh is illuminating. Once again, the curves below are the positive test rate and they are superimposed on the graphs of variant proportions over time from the CoVariants website.

India

India has had one large surge in 2021 so far, occurring in spring and associated with the Delta variant (which was first identified there; in dark green). It has had no summer surge, and no new variant since.

Bangladesh

Bangladesh, on the other hand, has had two peaks in 2021, a spring peak associated with the Beta variant (light red) and a summer one associated with the Delta variant.

The Sharp Decline in Infections in Florida and the Southern U.S. Shows Once More That Covid Surges Peak and Decline Naturally Without Interventions

The Delta surge in England has remained muted, even as restrictions have been lifted and schools have returned. In Florida and other Southern U.S. states it has been more severe, but it is now clear that it peaked in mid to late August and is now in many places in steep decline. Florida, Mississippi and Georgia are famous for having lifted restrictions either last autumn or in the spring and not imposing new ones in response to the arrival of Delta. In Florida the Governor actively opposed the imposition of mask mandates by school districts. Yet new daily reported infections in the Sunshine State have been in steep decline for weeks – see the positivity graph above. Declining daily reported infections for the three southern states are shown below.

These states show what an unmitigated surge of the Delta variant can look like. They demonstrate, once again, that the epidemic peaks and declines naturally with no need for interventions.

The big question now is, is Delta the last variant, does it represent a kind of evolutionary endpoint for SARS-CoV-2, or will another variant capable of partial immune evasion and thus causing a surge emerge in the coming months?

The worldwide graph of reported infections (below) clearly shows the three variant-based waves since autumn 2020 – B.1.177 (20A.EU1, the ‘Spanish’ variant) in autumn 2020, Alpha in spring 2021 and Delta in the summer.