Tweet

This Thread may be Removed Anytime!

Twitter may remove this content at anytime! Save it as PDF for later use!

More from @vipintukur

Vipin M. Vashishtha

@vipintukur

15 Jan

Viral dynamics & duration of PCR positivity of the #Omicron variant

In this study, longitudinal RT-qPCR tests collected between July 5th 2021 & January 10th 2022. This included 97 Omicron infections and 107 confirmed Delta infections 1/

Here are trajectories from individuals detected ≤1 day or ≥2 days since a previous negative or inconclusive test. 2/

Omicron infection duration was similar to Delta (both ~10 days), but Omicron infections had lower peak viral loads (higher peak Ct values). 3/

Read 10 tweets

Vipin M. Vashishtha

@vipintukur

1 Jan

How can you deal with a virus that has the capability of even switching its entry route?

Laboratory experiments demonstrate that #Omicron has switched its route of entry in to human cells. 1/

This is likely to influence #Omicron spread and the types of cells it can hijack. 2/

#SARS2 can enter cells via two routes, both routes require spike activation by proteases.

Route 1: Cell surface fusion, triggered by #TMPRRS2.

Route 2: endosomal fusion, triggered by cathepsins.

So far SARS2 has favoured Route 1.
3/

Read 15 tweets

Vipin M. Vashishtha

@vipintukur

13 Nov 21

What happens if we allow #SARS2 to become endemic? What’s going to happen to us & what’s going to happen to the virus?

If we allow it to become endemic—and some would argue that it is already endemic—this does not mean that it is going to attenuate, not whatsoever. 1/

It is not true that more transmissible versions of #SARS2 will be more benign. What we are seeing is more aggressive, more transmissible versions which are creating more severe illness. And the virus is still adapting to our physiology. It’s doing it at a fantastic rate 2/

What we’re going to see is that it will continue to work against our immune systems, meaning become more immune evasive. It’s going to become more chronic as an infection. 3/

Read 14 tweets

Vipin M. Vashishtha

@vipintukur

12 Nov 21

Natural immunity post-#SARS2 infection may not be perfect agains #Delta variant!!

A new study from #Australia:

“The duration & magnitude of #SARS2 immunity after infection, especially wrt the emergence of new VOCs”

1/

At 12 months after mild-COVID19:

1->90% of convalescents remained seropositive for RBD-IgG & 88.9% had circulating RBD-specific memory B cells.

2-Despite this, only 51.2% convalescents had serum neutralising activity against homologous live-SARS2 virus

2/

3-The neutralising activity decreased to 44.2% against live Alpha, 4.6% against Beta, 11.6% against Gamma & 16.2%, against Delta

4-Spike & non-Spike-specific T cells were detected in >50% of convalescents

3/

Read 7 tweets

Vipin M. Vashishtha

@vipintukur

15 Oct 21

Iranian #COVID19 epidemic: Salient features

Continued circulation of #SARS2 from late jan 2020 to Sep 2021 in iran despite >100% attack rates in 11 provinces. 1/

As of Sep 21, only 48% (95% CI: 43-55%) of COVID deaths in Iran have been reported. Approx 0.4% of the population have died of COVID so far

Estimated #IFR increased by a factor of ~2 over the course of the epidemic (from wave 1 to 5).

Across different ages, the 3rd wave in Oct 2020 & the current wave with #Delta had the largest impact on younger age-groups. 3/

Read 5 tweets

Vipin M. Vashishtha

@vipintukur

14 Oct 21

Are the #boosters already waning?

Booster effectiveness against breakthrough coronavirus infection is already waning.

The protection against infection among Pfizer booster recipients ages 60+ topped out by day 30 then fell steadily. 1/

By day 58, the #booster appeared to be providing around 40% of the maximum increased level of protection above the initial 2-dose series.

New data finds boosters are helping more than just 50+, but that the effects already appear to be decreasing. 2/

Bottom line: The case for boosters to prevent infection for all adults is now far stronger, if that is our goal. But how long that protection lasts remains unclear at best and boosters may turn out to lower the #Ro of #SARS2 only briefly. 3/

Read 5 tweets

Share this page!

Vipin M. Vashishtha

Try unrolling a thread yourself!

More from @vipintukur

Vipin M. Vashishtha

Vipin M. Vashishtha

Vipin M. Vashishtha

Vipin M. Vashishtha

Vipin M. Vashishtha

Vipin M. Vashishtha

Did Thread Reader help you today?

Like this author's thread?