ICMR-NIV study on P.2, the variant originally found in Brazil since ~April 2020 (WHO). Also called B. or zeta, it is now being rapidly replaced by P.1 in Brazil.

ICMR/NIV observed its effects on hamsters in comparison with P.1.

See thread

Presenting some context first. This variant P.2 was only seen in 2 samples so far in India; from asymptomatic travelers who arrived from Brazil and UK.

In Brazil, it is also being phased out by P.1 (deeper colour in recent weeks of 2021, genomic data from Manaus, Brazil).

Study from Brazil showing how P.2 is being phased out by P.1. The latter variant has the N501Y mutation in addition to E484K, among several others.


The ICMR/NIV study on hamsters showed that compared to P.1, the animals appeared to develop more severe lung disease.

9 hamsters each were infected with P.1 & P.2. The clinical parameters suggested P.2 was more severe, but the changes were not statistically significant.

An earlier study by ICMR/NIV had shown that only minimal loss of neutralisation occurred with this variant against covaxin (1.9 fold) & from sera (1.09) from natural infection. This reduction is not huge in comparison with other studies on variants.


This earlier ICMR study (see thread) implies that the variant P.2, in spite of the mutation E484K (shared with several other variants including P.1 & B.1.351) might not have the firepower needed to escape protection by vaccines, though it has been implied in reinfection.

P.2 has been implicated in two cases of reinfection in Brazil, see the paper attached and the pre-print below

Reinfection of a 45 year healthcare executive during October 2020 in Brazil, suggests P.2 variant was involved.


In Kerala, India @bani_jolly @vinodscaria et al studied breakthrough infections in 6 fully vaccinated healthcare workers (Covishield)

4/6 cases were from B.1.1.7.

None of these were severe.

One case had E484K; N501Y was noted in four (B.1.1.7).


The Kerala breakthrough infections (see thread) occurred mostly in March & 1st week of April, that was before B.1.617.2 replaced B.1.1.7 as the dominant variant. This explains the variance of these findings with Delhi, where 48% breakthrough infections were B.1.617.2

48% of breakthrough infections that occurred in 69 (2.6%) of 3235 vaccinated healthcare workers in Delhi Apollo hospital were from B.1.617.2 (Delta) variant. Covishield was used here, 51 of 69 had received both doses.

It is however important to keep track of variants as they arrive / emerge, and study their ability to cause disease, speed of spread, & capability to escape protection from vaccines.

These studies from ICMR/NIV are proof that such diligence exists, and this is reassuring.

The @ThePrintIndia writes about how P.2 variant was discovered in India. See detailed thread above.



• • •

Missing some Tweet in this thread? You can try to force a refresh

Keep Current with Rajeev Jayadevan

Rajeev Jayadevan Profile picture

Stay in touch and get notified when new unrolls are available from this author!

Read all threads

This Thread may be Removed Anytime!


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

Try unrolling a thread yourself!

how to unroll video
  1. Follow @ThreadReaderApp to mention us!

  2. From a Twitter thread mention us with a keyword "unroll"
@threadreaderapp unroll

Practice here first or read more on our help page!

More from @RajeevJayadevan

10 Jun
Covaxin tested against two variants B.1.617.2 (India) & B.1.351 (S Africa). Mild reduction in neutralization ability noted; 2.7 and 3-fold, which is a smaller loss compared to other vaccines, reports ICMR/NIV study.
See graph for comparison.
1/n biorxiv.org/content/10.110… Image
Neutralizing ability is one of the parameters scientists use to measure a vaccine's firepower against a virus.

If the vaccine is very effective, then its ability will be 1 or close to 1 -that is, in comparison with how effective the same vaccine was against the old virus.

If the virus has become so smart, it will then take several times the original "neutralising power" to kill it.

e.g. If the amount of vaccine required to kill the new variant is 10 times what it took to kill the old virus, we say the neutralising ability is 10-fold lower.

Read 14 tweets
9 Jun
Cell-to-cell (sideways) transmission of the SARS-CoV-2 virus is described in this research from Ohio State Univ & Washington Univ.

Authors find this process, unlike the traditional 'cell-top entry', is not deterred by neutralizing antibodies.


biorxiv.org/content/10.110… Image
Traditionally we hear about virus entering the exposed surface of the cell, like a bug flying in through the open window of a multi-apartment complex.

Now, imagine this bug burrowing through the walls into all the neighboring units. That essentially is cell-to-cell entry.

The problem with this process is that our neutralising antibodies might not be able to stop it.

These antibodies are designed to stop the bug from entering through the window, but not from burrowing through the walls between adjacent apartments.

Read 5 tweets
8 Jun
D Dimer: A test that leads nowhere?

25% of 150 recovered COVID-19 patients had elevated D Dimer at 4 months. 81 were outpatients.

The exact role of D-dimer in COVID-19 is unclear; it does NOT predict PE unless there are concomitant clinical clues.


Traditionally D-dimer is elevated when there are fibrin degradation products associated with clots. But D dimer is also elevated in other inflammatory conditions, trauma, post-op state / malignancy.

In COVID-19, its role is primarily as a marker of severity & inflammation.
Studies in COVID-19 patients have shown that unless there are specific clinical pointers to a clot (leg or lung), an elevated D-dimer value ALONE will not be worth pursuing: we might end up chasing a bird that was never there.

Read 10 tweets
6 Jun
Evidence based medicine, finally.

The latest COVID-19 guideline from Directorate General of Health Services at Ministry of Health & Family Welfare @MoHFW_INDIA, are pristine no-nonsense science.


See thread.


Major features:

1. Bold and clear statement about asymptomatic infection:


2. No antibiotics

3. No place for HCQ, Zinc, Vitamins, Ivermectin on the document

4. Clear instructions on steroid dose. One dose, fixed duration.

5. No steam inhalation advised (people sometimes do this in excess).

6. Hydration, diet and positive mindset/social connections get attention.

7. Clear instructions on Remdesivir and Tocilizumab, these are to be carefully used - only in highly selected patients.

Read 6 tweets
6 Jun
Comparison of antibody response between covishield & covaxin by @singhak_endo & team.

515 subjects, of whom 90 got covaxin

95% overall anti Spike antibody response

98% for covishield, 80% for covaxin

Lower response in older people & diabetes




Antibody titre 115 AU/ml for Covishield and 51 for covaxin.

27 breakthrough infections occurred (4.9%) after both doses: 25 were mild, 2 were moderate, no deaths.

Risk of breakthrough infection:
5.5% with covishield
2.2% with covaxin

Listing some facts which will help understand the context of the study:

1. Anti Spike antibody is not the same as neutralising antibody. Its level is not known to reliably correlate with NAb, which is typically measured only in research labs. See my earlier tweet on this.

Read 7 tweets
6 Jun
Apparent increase in % of deaths among 30-44 years in Himachal Pradesh from 7% in 1st wave to 13% in 2nd.

On taking a closer look, (see thread) it is likely because the older age groups have come under vaccination umbrella.


As early as May 31, over 31% of >45 years age group in HP had been vaccinated, ranking first in the country.

This means that the death rates in the older age group will be lower.

Therefore, the % of deaths in <45 will appear larger.

See below.


(Continued, see thread above)

The shaded (green) parts are the vaccine-protected segment. (A few <45 also got vaccine, but mainly in healthcare/frontline worker groups).

If vaccination had not been done, the 2nd wave numbers in the shaded areas would have been higher.

Read 5 tweets

Did Thread Reader help you today?

Support us! We are indie developers!

This site is made by just two indie developers on a laptop doing marketing, support and development! Read more about the story.

Become a Premium Member ($3/month or $30/year) and get exclusive features!

Become Premium

Too expensive? Make a small donation by buying us coffee ($5) or help with server cost ($10)

Donate via Paypal Become our Patreon

Thank you for your support!

Follow Us on Twitter!