My Omicron Note: 20.12.21

Our defence against the virus should be multi layered.

We must realise that no single layer gives us 100% protection. However, together they join hands to protect us from this pervasive virus.

IAN M MACKAY

• November 11, 2021: Detected in Botswana
• November 14, 2021: Detected in South Africa 
• November 26, 2021: WHO classified it as a VOC.

SARS-COV-2 B.1.1.529:

• How easily does Omicron spread ?.
  • Omicron is spreading more easily than the earlier variants. 
  • It can cause reinfections ( Earlier it is accepted that past infection with coronavirus protects.)
  • It can infect people with two or three doses of vaccination.
  • It can spread from a vaccinated and asymptomatic persons.

So, Safe distancing, Masks and Sanitisation schedules (SMS) are the need of the hour.

• Will Omicron cause more severe illness?

Preliminary data suggests that number of death and hospitalisations have not increased in countries showing recent surge. It can be due to accumulated herd immunity, vaccination status or a less lethal strain. Time is important to prove the above theories.

• Will vaccines work against Omicron?

Vaccines protect us not only by producing antibodies, but also by an ill understood mechanism called cell mediated immunity, (CMI). This CMI protects us against severe illness, hospitalisation and death. We have not been able to quantify this CMI component among the masses.

• Immune escape: Vaccines have been documented to protect against the Delta variant which has a lot of mutations. 
• Delta has been circulating for last 10 months and our vaccine people need only 6 weeks to formulate a Delta specific vaccine. Why are they not coming out with a variant specific jab? Because in labs, they could not establish the inferiority of our present vaccines in protecting against the variants. 
• Hard data shows that the Delta surge is a surge among the unvaccinated. Nations are insisting on vaccination with the present vaccine till date.
• Wherever there is a demand for a new vaccine, the context must be examined. Commercial angle and other biases must be ruled out.
• Whenever there will be hard data in support of a new vaccine, it will take only 3 months to tweak the vaccine and expedite its authorisation. 

Till such time, we must have faith that our age old infection prevention rituals and the present vaccinations will give us adequate protection against the current infection.

• Will treatments work against Omicron?

The changed genetic makeup can reduce some of our flagship treatment protocols like the antibody cocktails. But it will be a matter of time before we can have dedicated therapeutics against the Omicron. Till such time, our existing treatment protocol is adequate to take care of these or any future variants.

• It is called the Omicron (B.1.1.529) Variant.

• As on date the two significant viruses circulating are Delta and Omicron.
• Delta continues to be the predominant circulating variant. ( except in South Africa where Delta has been replaced by the Omicron.)
• Our vaccines continue to be highly effective against severe illness, hospitalization, and death among people infected with the Delta variant in the hard data available in our labs. Hence there has been no need of a delta specific vaccine till date.
• The spike protein of the Omicron variant is characterized by at least 30 amino acid substitutions, three small deletions, and one small insertion. Notably, 15 of the 30 amino acid substitutions are in the receptor binding domain (RBD)
• The changes in spike protein indicate that this variant will have increased transmission. But hard science data is needed to establish that it is more transmissible and lethal than the delta virus.
• Some mutations near the FCS ( Furin Cleavage Site) has the propensity to make it more transmissible.

For role of FCS in transmission of Coronavirus as a whole, please refer to my blog. Only for immunologists.

• It takes months to collect hard data in real life to substantiate all hypothesis on lethality, disease severity, immune escape ( from vaccine and earlier infection), Antibody cocktail and diagnostic failure.
• The mutations on the RBD part of spike protein should theoretically give the virus some advantage against our vaccines and MCA antibodies on paper. However life is larger than Lab. often our lab results are proved wrong in real life. Till such time, all the opinions circulating in our social media should be taken as hypothesis not facts.
• Our protections should be multi layered as shown in this Swiss cheese model below.

Footnote: Delta has circulated in India since December 2020 and still is the major variants. We have developed adequate protection against Delta because of the April surge. Our present low number of cases can be attributed to this factor. (my personal.)

Source: WHO, MOHFW and CDC website