Friday Report: Issue 50
By: John Roberts, Matt Fletcher & Adele Groyer
COVID-19 Actuaries Response Group – Learn. Share. Educate. Influence.
COVID-19 is still one of the hottest topics for scientific papers and articles. The COVID‑19 Actuaries Response Group provides a regular Friday update with a summary of key papers and articles.
Vaccination
JCVI Unable to Support Universal Vaccination for Younger Teenagers (link)
In a long-awaited announcement, the JCVI has set out its thinking regarding vaccination of 12 to 15 year olds. Whilst it notes that “the health benefits from vaccination marginally outweigh the potential known harms”, it believes it is too finely balanced to recommend supporting universal vaccination of this younger group.
JCVI notes that it is not within its remit to consider wider societal aspects of vaccinating this group, including education benefits, although it does later discuss the potential disruption to schooling during any vaccination programme, particularly if carried out on school premises. It suggests that the government’s CMOs should be consulted regarding the wider societal benefits.
The Committee does however recommend that those at heightened risk be vaccinated, and that the list of conditions that would qualify for vaccination be widened.
Third Doses Recommended for Severely Immunosuppressed (link)
In its latest statement the JCVI has recommended that around 500,000 people aged over 12 who have severely weakened immune systems should receive a third dose “as part of their primary vaccination schedule”. This was informed by preliminary data from a trial that showed that 40% of immunosuppressed people still had low antibody levels after two doses.
JVCI makes it clear that this decision is a separate consideration from the wider question of booster doses, which remains the subject of further deliberation. The purpose is to offer this group, some of whom may not have generated an effective immune response after the first two jabs, another opportunity to enable an effective response to be triggered.
The statement also notes that those with less serious immunosuppression would be likely to be offered a booster dose in the event that a wider programme is implemented, as indeed will this group after a suitable interval.
The statement notes that either of the mRNA vaccines should be administered, except for those under 18, where it should be limited to the Pfizer jab.
Early Data on Israel Booster Doses (link)
With Israel again at the forefront of the global vaccination programme in respect of booster doses, we can expect the first data regarding their effectiveness to come from the country.
Sure enough, a very early study looks at the effectiveness of boosters, and suggests that there is a significant reduction in the likelihood of testing positive following a third dose. Results are stated at a 48% to 68% efficacy between days 7 and 13, increasing to a 70% to 84% efficacy in days 14 to 20. These estimates are in relation to a baseline position of having previously had two doses, as opposed to an unvaccinated scenario.
The paper acknowledges that with the booster programme only having started in early August, these are very early results and do not cover longer time periods or efficacy against serious illness.
Waning Effectiveness Noted in Major Study (link)
A comprehensive analysis of data taken from the regular ONS infection surveillance project includes some interesting comparisons and duration trends of the two main vaccines used in the UK in relation to protection against Delta.
The top-left chart shows that efficacy against infection is much higher initially for Pfizer, but appears to be waning faster. Noting that age effects may be a confounding factor, the top right chart looks at under 65s and splits at 35 and shows waning amongst all cohorts, noticeably in the 35-64 Pfizer group.
In the bottom-right chart there is clear evidence of how vaccination of those who previously had COVID, results in a much higher efficacy for both vaccines, at around 90% or higher. Although not shown, an equivalent efficacy figure for those with natural immunity only is stated elsewhere in the paper at 72%.
(For reference, BNT162b2 refers to the Pfizer vaccine; ChAdOx1 to AstraZeneca; ‘lthc’ refers to self-reporting of a long-term health condition.)
Variants
New variant C.1.2 identified (link)
In a pre-print study, the characteristics of a new variant with multiple mutations are described. The C.1.2 lineage was first identified in South Africa in May 2021 and has since been detected in seven other countries. The mutations are in the virus Spike as well as at the Receptor Binding Motif. Some of the mutations are also seen in variants Alpha, Beta and Gamma, and are associated with increased transmissibility and reduced neutralisation sensitivity. The study points out that this lineage has the potential to become a variant of concern.
The UK is monitoring this variant but has not yet designated it as a Variant Under Investigation. No data on the number of sequences of this variant found in the UK have therefore been published as yet, but the number is likely to be low.
“Mu” added to WHO’s list of variants (link)
The WHO’s list of Variants of Interest now extends to Greek letter Mu after variant B1.621 (first documented in Colombia) was added to the list on 30 August 2021.
Unlike Alpha, Beta, Gamma and Delta which are “Variants of Concern”, Mu is a “Variant of Interest”. Variants of Concern have demonstrated changes of global public health significance, while Variants of Interest have genetic changes that are predicted to have adverse effects which suggest an emerging risk to global health.
53 confirmed or probable Mu cases have been identified in the UK since the start of the pandemic until 1 September 2021. Five of these cases were recorded in the last week. This compares with 605,566 Delta cases, of which 70,179 were recorded in the last week.
Visual representations of the proportion of the total number of sequences by variant group are available at (link). Note that not all samples are representative, for example countries may prioritise certain mutations. The graphs below show high prevalence of Mu (yellow) in Colombia since April 2021, with some early signs of the emergence of Delta (green) in July. In the UK almost all sequences are Delta at present.
Variant statistics in England (link)
The table below shows numbers of sequenced or genotyped cases and deaths in England since October 2020. Delta accounts for the majority of these cases. The higher count of deaths among Alpha cases may be influenced by lower vaccination rates at the time Alpha was dominant. Delta death counts are likely to increase for cases identified so far because of the lag between testing positive and reporting of death.
Between 20% and 30% of cases were sequenced or genotyped in the earlier part of August, with reporting delays meaning that figures in the most recent weeks are subject to upward revision.
This data is from Public Health England’s “SARS-CoV-2 variants of concern and variants under investigation in England Technical briefing 22”. These briefings are published every second Friday.
Clinical and medical news
Baricitinib Trial Encouraging (link)
The Lancet has published the results of a global trial of baricitinib, an anti-inflammatory drug previously used to treat rheumatoid arthritis, in conjunction with standard of care treatment of hospitalised patients (remdisivir/dexamethasone). The trial showed a 38% reduction in mortality at the 28 day period, with one patient in every 20 treated surviving that would not otherwise have done.
The study covered over 1,500 participants between June 2020 and Jan 2021, with 50% receiving baricitinib and 50% the placebo.
Modelling
Monitoring actual and modelled hospitalisations
We first monitored actual hospitalisations in England against projections in Friday Report 48 (link). This updated our bulletin (link) summarising papers from London School of Hygiene and Tropical Medicine (LSHTM), Warwick University and Imperial College London which modelled the move to step 4.
The chart below shows an updated actual trajectory of hospitalisations in England against four of the projections produced by the groups:
- LSHTM central model (assuming waning immunity of 15% over the next 12 months)
- Warwick “green” and “pink” models which represent the two extremes of their assumptions on precautionary behaviour
- “Green” assumes a gradual move towards pre-pandemic behaviour over the period to March 2022
- “Pink” assumes an immediate step-change to a state close to pre-pandemic behaviour, with a full return to pre-COVID mixing reached by September 2021
In order to see the actual figures more clearly, we have removed the central Imperial projection which indicated much higher levels of hospitalisation than the other models.
This update shows that actual hospitalisations (blue) have been broadly similar over recent days. They are tracking below the LSHTM estimate and slightly above the Warwick green estimate, which is towards the lower end of the trajectories produced in the initial modelling papers.
We will continue to track the figures regularly.
Data
ONS Infection Study (link)
There’s been a convergence of infection levels between three of the four nations in the latest update from ONS published today (which as always is a week in arrears). Consistent with recent cases data Scotland shows a sharp increase, not far short of doubling, whereas England remains broadly flat, as it has done for some weeks now. Wales, whilst still the lowest, is increasing steadily, and Northern Ireland remains high but volatile, which may be related to smaller sample sizes and thus wider confidence intervals for each data point.
Possibly of concern is the data in relation to the oldest age groups, 70+, which has seen a consistent doubling of cases every fortnight from mid-June to late July, and after a brief pause in early August now appears to be on the increase again, resulting in a six-fold increase since mid-June.
ONS Antibody data (link)
The latest antibody data from the ONS shows levels in excess of 90% for over-16 year olds across the UK, ranging from 94.1% in England down to 90.4% in Northern Ireland, where uptake has been lower, particularly amongst younger age groups.
The main interest in this fortnightly release now appears to be in any evidence of waning, with some media outlets noting increased signs in the oldest (and thus earliest vaccinated) groups.
Looking at the 80+ age group, we can see that from a peak in early May, those displaying antibodies have fallen from 95% to 92% over the subsequent three months. The 95% confidence intervals are shown too to give an indication of the level of uncertainty with each week’s estimate.
To consider the mathematics of any likely impact of any waning in terms of serious illness, it is more instructive to look at the balancing figure – which in this instance has risen from 5% to 8%, a 60% increase. However, that is too simplistic a view, and there are other factors (the presence of T-cells for one) that form additional protection beyond that measured in this surveillance.
“R” Estimate
The latest estimate of R for England issued by the UK Health Security Agency is between 0.9 and 1.1. Given recent trends of both cases and admissions the fact that R is believed to be close to 1 should be no surprise.
The regional picture shown below suggests that in most regions there is no clear clarity as to whether there is growth or shrinkage, although at the bottom the range for the South West is from 1.0 to 1.4, consistent with the ONS infection data picture, and likely a result of the Boardmasters Festival.
And finally …
As it’s the 50th edition of Friday Report some of our contributors have taken the opportunity to come up with our favourite ‘And finallys’ from each edition.
Next Matt Fletcher reminded us of the very first “And Finally”, back in the first edition of Friday Report, in which an Australian astrophysicist ended up in hospital needing magnets extracted from his nostrils whilst inventing a device to prevent you from touching your face inadvertently.
And finally (2) … in our look back, in Edition 5 we reported on an enterprising farmer in California who let you invite a goat or a llama to join your Zoom meeting. Since then we’ve seen other challenges of Zoom meetings, including a lawyer joining a court hearing disguised as a cat, and the now infamous Handforth Parish Council meeting, so perhaps the soothing view of a llama might not be such a bad thing after all.
3 September 2021
