Tuesday meeting highlights 17 April

COVID returns sooner than expected.

This week, 6.7 - 7.3% of COVID tests turned positive, compared to nil the month prior.

Cases mild or asymptomatic (screening), severe disease not yet reported

(The last wave collapsed December 21)

1/6 While the return of COVID is only expected (cyclical), the short duration (3 months) of case-free gap is surprising.

This coincides with Bangalore waste water surveillance @TIGS_India showing viral load in all samples tested.

This means COVID is in circulation.

2/

Even among sedentary people, as little as ~4000 steps per day can reduce death / heart disease risk. Maximum benefit at ~9000.

There are many studies on step count, see thread. This paper also looked at how step count helped in a sedentary lifestyle.

1/5
bjsm.bmj.com/content/early/… There is no such thing as a 10,000 steps requirement for health.

Benefits start at much lower levels.

This study received wide attention, attaching my earlier tweet

2/

https://twitter.com/rajeevjayadevan/status/1689186435189080064

“Bed Rest” leads to loss of muscle

In healthy people over 60, just ten days of bed rest led to 1 kg muscle loss from the lower limbs.

Worse in people with illnesses.

In fact, there are very few real indications for “bed rest” now.
Exercise and early mobilisation is key.

1/6

Also called sarcopenia, this is a serious problem especially in the elderly, who might suffer an abrupt decline in their health as a result. Frailty creeps in, and once they lose their muscle/bone strength, falls and other complications occur.

Also affects younger people.

2/6

Long COVID study from Japan, published in Nature answers many questions

🔹At 1 year, 20.7% had it, higher in adults.

🔹Most initial infections (89%) were mild, 60% had Omicron

🔹Vaccine has no preventive effect

1/3





2/3

Link

nature.com/articles/s4159…

Lung 🫁 function declines long term - even after *mild* COVID.

Major Denmark study measured PFT before, 6 months after and 2 years later. They compared with uninfected people.

The speed of decline leveled off at 6 months, but failed to improve back to baseline. See graph.

1/4





The accelerated decline among patients slowed at the 6 month mark, and eventually followed the expected “normal” age related decline. But it did not return to baseline.

DL co increased past the 6 month mark, but the was no corresponding improvement in breathing difficulty.

2/

Spent a week in Singapore, did not get COVID despite JN.1 surge. Sharing some travel tips to stay safe.

Masks, worn according to situation, keep viruses away. Here is what we did.

1. Airports are high risk, hence kept them on all the time

2. High risk while boarding

1/9

3. Airplane jet bridges are tiny tunnels that are crowded, kept masks on.

4. Until the plane takes off and is cruising, cabin isn’t well ventilated. People were coughing throughout, a common problem nowadays. Masks stayed on.

5. At meal times (cruising), masks came off.

2/9

Research from Harvard shows SARS-CoV2 virus doesn’t necessarily require the ACE2 receptor to enter cells.

Antibodies generated against RBD of the virus naturally attach to FcγR1 receptors on immune cells.

This complex can serve as a receptor for virus to attach, and enter.

1/6

https://twitter.com/marionkoopmans/status/1728685868100014262

FcγR1 receptors are found on the surface of immune cells like macrophages and monocytes. When a floating antibody attaches on these “landing pads”, these cells get activated.

Authors find that this antibody-receptor complex can also serve as a substitute of sorts for ACE2.

2/

Hybrid immunity not protective, may worsen risk of infection

48-fold increased risk of getting a repeat Omicron infection among those who had prior Omicron infection

Large study from McMaster University Canada on vaccinated older adults, includes immune response details👇

1/5





Study was done from July to September 2022, when Canada was going through a 2nd Omicron wave. They wanted to find out who was at greater risk of getting a 2nd omicron infection. Surprisingly, authors found that those who had prior omicron infection where are FAR GREATER risk.

2/

Dengue virus infects lab cells more easily in the presence of antibodies generated after COVID-19

2 types of cells K562 & U937 were used, findings compared with control serum.

Evidence of ADE (antibody dependent enhancement) of Dengue, facilitated by SARS-CoV2 antibodies.

1/10





ADE is well-known in dengue👇

Dengue virus has 4 serotypes.

Instead of being protective, antibodies generated against one serotype paradoxically worsens the next bout of dengue by another serotype.

It has also been implicated in a few other viruses such as RSV, HIV.

2/

Enjoyed being invited to this fun podcast mainly about immunology related to COVID vaccination without jargon, adding some of the latest research summaries.

With @alexmeshkin @TakeWeightOffMD @julesannenphd

Immunology discussion starts at 10 min

podcasts.apple.com/in/podcast/har…

https://twitter.com/alexmeshkin/status/1666635984837148673

Linking a few relevant studies in the context of the podcast

1. The Columbia University Study on Bivalent vaccines

https://twitter.com/rajeevjayadevan/status/1655883045453590531

Abnormal brain function found in Long COVID patients with cognitive impairment

Italy study compared multiple parameters with healthy controls

TLDR: Brain has delicately balanced excitatory and inhibitory circuitry. This was disrupted in Long COVID, but not in controls.

1/4 Link to paper

sciencedirect.com/science/articl…

Thanks @THAILANDMEDICA1 for noticing this study

See thread below

2/

Omicron can reinfect in 16 days.

Thrice-vaccinated healthy 52 year-old man gets two separate infections by BA.1.1 and BA.2.

Symptoms lasted 6 and 7 days.

Reinfection used to be considered impossible/unlikely if anyone tested positive within 90 days.

Times have changed.

1/3

https://twitter.com/leseerlaubnis/status/1665176606103461889

Report from Belgium, April 2022

2/3

https://twitter.com/RajeevJayadevan/status/1516002595793702915

Role of genes in critical COVID

Article headline can be misleading however, suggesting that “being born with bad genes is the reason for COVID deaths”

The problem is that genes are assumed to be like “fingerprints” by most people.

That’s not true. See detailed thread.

1/15 This study was done on people who had critical Covid, predominantly in the pre-vaccine era.

Using GWAS, authors found that the expression of certain genes was greater in people who had more severe disease.

nature.com/articles/s4158…

2/

XBB was born in summer 2022 by recombination

This is a landmark event in the pandemic

Until now, variants used individual mutations

But XBB was born from “marriage” of two different viruses, getting a massive advantage at one shot

It is now replacing earlier Omicrons

1/5

https://twitter.com/systemsvirology/status/1658595090410110976

This graph shows the relative growth difference between XBB and other Covid variants. See annotations.

These are lab studies, and need not represent human disease.

However, indications are that XBB.1 has the same disease severity as BA.2.75.

2/5

Detailed study of immune response to Omicron-based boosters and natural infection

Several points (see thread)

🔹mRNA vaccination leads to worse immune imprinting*

(*In plain English: ‘fixed old memory that cannot be updated’)

🔹Longer gap = Better

1/9

https://twitter.com/yunlong_cao/status/1653804041821093889

For those who are unfamiliar with Dr Cao’s work: relentless research by @yunlong_cao and colleagues from China has kept us updated on the latest Omicron versions, and deserve appreciation. See his timeline for prior works, which many of us have retweeted over the years.

2/

COVID-19 increases the risk for heart attacks and other outcomes in the future

This interview with Dr Soumya Swaminathan @doctorsoumya by @MKadampad was published in @ManoramaDaily

Attaching her recent interview by @ANI quoted by @EconomicTimes

See thread for links

1/4 twitter.com/i/web/status/1… Dr Swaminathan’s video interview link here

2/
m.economictimes.com/news/india/ind…

Arteries became stiffer after even mild COVID - among young healthy volunteers

Study compared stiffness levels measured just prior to pandemic vs. well after COVID symptoms fully resolved

The parameters only worsened with time, and did not improve.

See long thread 👇 There are several measures of arterial stiffness, for example cfPWV (carotid-femoral pulse wave velocity).

Arterial stiffness refers to the reduced ability of arteries to expand & contract in response to changes in blood pressure, and is linked with cardiovascular disease.

2/

Monkeypox detected in Pakistan. The first case was a 25 year-old man who recently returned from Saudi Arabia.

See thread for news report from @AlJazeera and for the first case report in India of fatal encephalitis, Monkeypox in a man who returned from UAE in July 2022.

1/4

https://twitter.com/jakramaimc/status/1651155220016111616

Report of fatal encephalitis, Monkeypox. Thanks @hellopragya22 @Aravind22729416

Very few cases were eventually found in India, where it did not spread in the general population despite early concerns by a few experts. In fact, it died down quickly as we had predicted.

2/4

https://twitter.com/hellopragya22/status/1650157996725420035

Tuesday COVID Meeting highlights 26 April Cochin

🔹No further increase in hospital caseload
🔹Reluctance to testing despite Government advisory
🔹Reluctance to wear masks, hospitals however insist
🔹Most people have mild symptoms
🔹Deaths mainly among vulnerable people

1/17 An audit of COVID deaths revealed the following

Age ranged from 33, 49, till 87

Man, 33, died of aspiration pneumonia from severe alcoholism but he was COVID positive

49 year old was transplant recipient who developed bilateral pneumonia, stopped vaccination after 1 dose

2/

Effect of fasting on blood sugar in non-diabetics

Australia study concludes intermittent fasting yielded “better results” than traditional calorie restriction.

I am not so sure👇

❗️Fasting group LOST MORE MUSCLE, had more side effects

Calorie group lost more fat & waistline. Authors compared dietary interventions on people deemed to be at higher risk of developing diabetes in the future.

Intermittent fasting was defined as restricted eating within a four-hour window in the morning, followed by 20 hours fasting, three times a week.

2/

Omicron is a stealth virus

Fascinating research from Germany reveals vital difference in antibody response to Omicron versus prior variants

Ongoing study of 1850 children since 2020

Very few developed antibody after Omicron infection (18%), versus 68% for prior variants

1/9 Such meticulously planned studies will help unlock the mysteries of the pandemic.

These authors have tracked 1850 children from the beginning of the pandemic, studying their immune response to infections by various forms of the virus.

2/