Detailed graphical representation of the story of the US elementary school teacher who infected 12 of her masked students by reading aloud without mask.
Lessons:
1. Multiple factors have to be in place to prevent outbreaks
3. Masks did not protect the children from getting infected.
4. The teacher was unvaccinated, and had attended social gatherings.
5. She developed mild “allergy” symptoms which she chose to ignore (this could happen to anyone: wisdom is easier in hindsight)
2/
6. Children in the next classroom also got infected, showing how far aerosols can travel
7. This also shows physical spacing is of limited value (think cigarette smoke in a room, spacing doesn’t change how the smoke spreads or smells)
3/
8. In crowded, resource-poor settings, it is hard to implement all layers of protection.
9. Recent vaccination of the teacher could theoretically have prevented this. But if she socialised a few months AFTER receiving the shot, she could pick up mild/asymptomatic infection.
4/
This is because antibody levels naturally drop after a few months, allowing the virus to infect again. This is happening commonly.
10. Social behaviour (and ventilation) are as important as other layers of protection; vaccines & masks alone aren’t going to make it go away.
5/
11. Perhaps the most effective answer is to radically change the classroom concept (where feasible) from indoors to outdoors.
Why? Because aerosols are far less dangerous OUTDOORS than indoors. If online education can work, so can the outdoor concept.
6/6
• • •
Missing some Tweet in this thread? You can try to
force a refresh
Multiple issues with the widely quoted NEJM Israel study on boosters
Long thread👇
1. Authors report a lofty reduction in infections & severe cases by a factor of 11.3 & 19.5 in the primary analysis, where rates are compared between boosted & non boosted groups.
2. In secondary analysis, this factor is down to 5.4. Secondary analysis compares rates within the SAME group, by timeframe. This is more believable not only because comparison is within the same group, but also because we know higher antibody levels reduce infection rates.
2/
Note: secondary analysis is available ONLY for infections, not severe cases.
In other words, we do not yet know if this 5.4-fold reduction in ‘infection’ will translate to reduction in hospitalisation/death later.
3. No mention of number of people who were hospitalised.
3/
Large cohort of 673,676 vaccinated, 62883 past infection, & 42,099 vacc + past infection. The groups were matched to exclude confounding.
They looked at remote & recent past infection separately. Those who were infected in 2021 had greater protection than 1 year ago.
2/
The vaccinated group had a 27-fold greater risk of SYMPTOMATIC breakthrough infection compared to natural infection. The risk was 13-fold for ALL breakthrough infections.
A single dose of vaccine further increased the level of protection for those who had past infection.
3/
Audit of 281 COVID-19 deaths in Ernakulam showed that 98.2% of the deaths occurred among those who had not been (fully) vaccinated. i.e. only 1.8% of deaths were fully vaccinated.
The reason why children are easily able to get rid of the SARS-CoV-2 virus is due to a super-efficient innate immune system in their airways, as was hypothesised earlier (not from ‘less ACE2 receptors’).
Enhanced spread of Delta variant might not be due to “immune escape”, but rather from more efficient cell-entry mechanisms & improved replication (processing of spike protein).
Researchers tested out a “Frankenstein” delta variant fitted with an alpha spike, and found that this hybrid virus was even less efficient than the alpha itself.
P681 mutation enhances the S1-S2 furin cleavage process. This improves entry into the cell.
2/
P681R also helps during processing of spike protein within the cell.
Both these factors effectively mean that the virus can not only enter, but also multiply efficiently.
This translates to enormous numbers of viruses found early during infection, and thus greater spread.
3/
Transparent science communication to the general public.
Today’s Manorama paper carried a fact-based advisory about potential post-Onam surge in Kerala by @RajeevJayadevan & others at IMA Cochin.
In Kerala, Onam is a festival that everyone celebrates.
Detailed thread 👇1/16
This advisory comes from numerous Tuesday meetings of experts held by IMA Cochin - ever since the start of the pandemic where we continuously monitor events locally, nationally as well as around the world.
We have given out advisories in the past which helped policymakers👇
2/
This timeline shows Kerala‘s pandemic of contrasting with the national average. The only surge in 2020 was in October, see graphs.
The number of cases in October 2020 was 6 times that of August 2020.
However in 2021, the “baseline” number of cases is 12 times that of 2020.