COVID-19 Notes
By Dr. Satish K Gupta*
Will Omicron Serve as Live Nasal Vaccine and Save the World?
On global scale, as Omicron spreads rapidly, it appears that everyone will be infected by the new contagion. A top US scientist Anthony Fauci says, “Omicron, with its extraordinary, unprecedented degree of efficiency of transmissibility, will ultimately find just about everybody.”
How is pattern of Omicron infection different from previous variants?
- A pattern that can be noticed across countries is that *Omicron wave is taking about 3-4 weeks* from introduction to peak irrespective of weather, temperature, and demographics.
- Omicron is so transmissible that it’s reaching all the susceptible people, either from waning immunity from vaccination or from the previous infection or despite both. That’s not something world saw in previous waves. It speaks to the extraordinary speed and transmissibility of the Omicron wave.
The Omicron scenario in India
Omicron is already in the stage of community transmission. If one goes by the official figures, one may just count 2 to 3 lakh cases a day. But the actual scenario is undoubtedly different. Most of the cases are missed as 70-80% of the infected are asymptomatic which are never tested nor reported and the rest have mild symptoms as per a study from ISACOG reported by the Ministry of Health and Family Welfare. Under testing, self-testing and under-reporting are obvious reasons.
Is it the first time that we are seeing asymptomatic cases?
No, in previous waves, nearly 40% of infections were asymptomatic, but the figure has just doubled in the current wave.
Omicron is infecting even the fully immunized people. In the above study, a little over 90% of the cases for whom vaccination status was known had taken both the shots. The trends fit findings in other countries.
Are vaccines and masks failing in the face of Omicron?
Yes, surprisingly, IHME (Institute of Health Matrix and Evaluation) model suggests that the transmission intensity of Omicron is so high that policy actions—e.g., increasing mask use, expanding vaccination coverage, or delivering third doses boosters— have limited impact on the course of the omicron wave.
Why do you think Omicron is live vaccine?
With such high rates of natural infection and nearly 80% asymptomatic cases, one ought to take it as nature’s live Omicron vaccination of world population, causing side effects of fever, cough and body ache in about 20% people. It might be blessing in disguise protecting from future infections.
Will Omicron infection in nose produce (local) immunity?
In cases of Omicron Infections, a very high concentration of virus has been noticed in the nose and upper airways. The same is also evident by low CT values found in most RT PCR reports during the current wave. The viral load infection of nasal epithelial cells stimulates efficacious early mucosal immune response to produce local immunity by formation of IgA antibodies which coat the nasal and upper airway mucosa preventing future infection. Nasal vaccines work on the same principle.
Will Omicron serve as live nasal vaccine to humanity?
Omicron infection might serve as a natural live nasal vaccine of the current century.
❗ Live vaccines are the best vaccines because they create an excellent immune response (cellular and antibody) and often provide lifelong immunity with only one or two doses, as in the case of Measles.
❗Intra nasal vaccines work by producing local IgA antibodies. And IgA antibodies have been suggested to be natural, polyreactive, cross-reactive. So, it is possible that the local nasal immunity produced by Omicron infection is effective against future variants too. However, only time will tell if the Omicron-induced Local IgA Immunity stands the testimony of future variants. If yes, that will be the end of the pandemic.
The vast transmission of Omicron
By March 2022, a large proportion of the world will have been infected with the omicron variant. With continued increase in COVID-19 vaccination, the use of third vaccine dose, and high levels of infection-acquired immunity, for some time, global levels of SARS-CoV-2 immunity should be all-time high. And surely, it should break the cycle of transmission for the coming few months at least.
How long Omicron induced immunity last will decide the future of the pandemic!
Sars Cov-2 is a rapidly mutating virus. The upcoming variants have the potential of immune invasion. The latest in the series, Omicron, has already demonstrated its might by re-infecting those with past infection. So, it remains an open question as to whether Omicron infection will give the permanent live virus vaccination effect or not because there is a great deal of variability with new variants emerging.
Will Omicron be the last variant of Sars Cov-2?
Omicron will not be the last variant. Clearly, with such high viral circulation as being seen now, there’s a high probability that another variant will be coming up soon. Barely two months into Omicron, and the world is already witnessing sub-variants of Omicron like BA.2 and BA.3
Why is Omicron mutating so fast?
High virus circulation drives the risk of emergence of newer variants. We’ve seen that for Alpha that emerged in the UK and later for Delta in India. We are seeing the same for Omicron.
Will the newer variants be more dangerous?
Let’s hope that they are not. Based on the evolutionary advantage to a virus, it is more likely that newer variants will attenuate, suggesting that they will further be associated with less severe disease. The virus also dies as it kills its host leading to evolution disadvantage. But mind you, viruses can’t think, and Sars Cov- 2 is known to spring up surprises. So, let’s hope for the best-case scenario, that Omicron immunity ends the pandemic.
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*Dr. Satish K Gupta is an MD in Medicines, a Visiting Senior Consultant Physician and Internist at Max Super Speciality Hospital, and a Clinical Assistant Professor at GS Medical College, Chaudhary Charan Singh University, Meerut. He is the author of Journey of COVID in India: A Doctor’s Perspective.
