Does Omicron cause less severe disease than Delta?
Omicron may be comparable to the measles virus-one of the most transmissible viruses science has known so far!
ByDebananda S Ningthoujam
Updated 16 Jan 2022, 4:02 pm
A new surge of COVID infections is raging across the world especially the US, parts of Europe, China and India. In the US, daily caseloads have swung as high as 5 lakhs to over 1 million. In india, the tally of daily cases are now at over 2.6 lakh and one cannot say at what level will it peak. We all need to prepare for the worst, while hoping for the best.
According to the UK Zoe COVID study, the common symptoms of Omicron are:
- Mild fever
- Scratchy throat
- Runny nose
- Intense body pain
- Night sweats.
Apart from the aforementioned symptoms, recently reported symptoms include nausea, vomiting, and loss of appetite. Another unusual symptom observed by the Zoe COVID study is skin rash (TOI, Dec. 30, 2021). This could be a manifestation of the inflammation triggered by the SARS-CoV-2 coronavirus. Skin rash could include COVID fingers and toes (also called chilblain), that could lead to red and purple bumps on fingers and toes, which could induce pain and itchiness. Two more types of rash may also emerge: hive-type and prickly heat type rash.
Additional symptoms in children include croup ("barking cough") and inflmmation in various organs. Another strange symptom in people who recovered from Omicron infections is intense back pain.
The most perplexing question is: does Omicron cause less-severe disease than Delta? The jury is still out on this issue. Though all preliminary reports indicate the mildness of the disease triggered by this new variant, it's not yet clear if that's due to the variant itself versus the populations it's infecting (The Scientist, Jan. 14, 2022).
A constellation of mutations on the viral spike protein render vaccines far less effective at preventing infections than they have been with previous variants. The new variant is highly contagious. Its R value is estimated to be about 7, i.e. a person infected with Omicron can potentially transmit it to 7 other people (some put the R value at even 10 or higher). Omicron may be comparable to the measles virus-one of the most transmissible viruses science has known so far!
In the US, hospitals are overwhelmed with patients as new cases and hospitalisations surge. There has also been delayed spike in deaths that lagged slightly behind case numbers. Also, record numbers of children are being hospitalised with COVID-19, according to the New York Times. There has been a much-hyped narrative that Omicron is mild? Is it indeed so? This new variant was first detected in South Africa with a relatively young population, majority of whom are either vaccinated or recovered from COVID, or both. Is Omicron mild so far due to the acquired immunity and clinical knowledge built up in the last 2 years? The varying levels of vaccination, hospital infrastructure, and other demographic profiles in different countries and regions complicate the matter further.
However, the reply to the confused messaging that Omicron is mild must be that the Omicron variant must not be underestimated. We cannot afford to be complacent. According to Ghebreyesus, WHO DG, it's more appropriate to say that Omicron is "less sever" than other variants than to call it "mild."
Those who don't have prior immunity-not yet vaccinated or infected-or those who're immunocompromised due to co-morbid conditions are likely to develop severe symptoms and possible deaths as a result of an Omicron infection. A less-severe variant that's far more transmissible can still overwhelm the healthcare facilities. It's well worth remembering that a small fraction of a huge number is still a big number!
As per a recent report in the journal Nature, most vaccines are far less effective against Omicron than other variants, especially the vaccines made with inactivated virus, e.g. Covaxin. As all the current vaccines were designed to target the earlier variants, there is an urgent need to develop Omicron-specific vaccines (Moderna and Pfizer have already made plans to make such vaccines). Meanwhile, it's imperative to administer booster doses to all eligible populations.
Besides the oral pills for COVID-molnupiravir and paxlovid-already approved in several countries, the WHO has just approved two new drugs for treating COVID patients. These are baricitinib and sotrovimab (The UN News, Jan. 13, 2022). The former is a drug for rheumatoid arthritis, now repurposed for COVID and the latter is a monoclonal antibody. These new medicines have been recommended for treatment of COVID patients, one for crtical ones and another for non-severe cases. Baricitinib is to be used for critical patients in combination with corticosteroids.
The monoclonal antibody, sotrovimab, is targeted at non-severe COVID patients.
Third Wave Scenario
According to an IISc-ISI model, the present COVID-19 wave in India may flatten by March or April (The Mint, Jan. 12, 2022). The peak may witness more than 8 lakh daily cases! Cases may start declining by January or February end, as per this model, but it may vary from state to state. They assumed three scenarios: 30%, 60%, and 100% susceptible population. If more people are suceptible to the new variant, the third wave may linger much longer.
If a new and severe variant emerges, there may still be another wave of COVID infections.
As per a report by Dr Manindra Agarwal, IIT Kanpur, the third wave may end by April. He also warned that the election rallies can prove to be super-spreaders (The ET, Jan. 15, 2022).
A multi-pronged approach can only prevent or mitigate the third COVID wave in India triggered by Omicron, and compounded by Delta:
- Enhanced tracking, testing, and isolation measures,
- Strict surveillance of positive cases, including genomic surveillance,
- Completing the single dose vaccination of the entire eligible population,
- Enhancing double vaccination rate from 60 to 70% in next few weeks,
- Strengthening healthcare infrastructure especially in rural, remote, and peripheral areas e.g. the North East,
- Limiting crowding in public spaces such as markets, malls, and halls,
- Conducting election campaigns, at least, partly in the virtual mode; as lections are unlikely to be postponed; and limiting the crowds in meetings, rallies, and campaigns to the minimum possible.
We also need to remember that vaccines and boosters may not protect us against Omicron infections but they will go a long way in protecting us from serious hospitals and possible deaths.
In addition, hospitals including those in Manipur need to stockpile the new anti-COVID drugs such as molnupiravir, paxlovid, and PBI-0451 (experimental drug, a protease inhibitor, made by the firm, Pardes Biosciences), as and when they become available (Al Jazeera, Dec. 28, 2021).
Possible Measures for Manipur
We need to assume that there may be a third wave in Manipur too. Even if that may turn out to be a wrong anticipation, it's better to err on the side of caution. Accordingly, we must initiate measures to squarely face a possible third wave in our state. These may include:
- Preparations for administering vaccines to kids in Manipur & booster shots to high-risk people (elderly, healthcare workers and people with weak immune systems).
- Conducting immediate seroprevalence studies to understand what percent of population in Manipur and in its different districts are still susceptible to the coronavirus.
- Speeding up vaccinations in a big way; aggressive vaccinations with monthly targets to cover all eligible population with first doses in the next few weeks (4-6 weeks); and targeted vaccinations of all adult population with second doses in the next 2-3 months.
- Regular & repeated COVID testing in hotspots.
- Enhancing the ratio of RT-PCT to Rapid Antigen Testing (RAT).
- Weekly "awareness messaging" about the pandemic to the public by a designated healthcare official.
- Genomic sequencing of a subset of positive cases and surveillance of the variants including the delta variant: which COVID strains are there in Manipur, where are they, and where are they moving towards; and whether any new variants are emerging.
- Contact tracing and government-monitored isolation of positive cases, wherever feasible.
- Boosting up healthcare provisions such as medical oxygen plants, tankers and cylinders; steroids, antifungal drugs, oxygen concentrators, ventilators, oximeters, masks, PPEs, sanitizers etc.
- Strengthening of healthcare infrastructure such as construction of new COVID hospitals.
- Provision of more COVID care centres (CCCs), more Covid beds and ICUs in existing hospitals
- Constitution of a special taskforce for the third wave; a separate taskforce for pediatric COVID is also highly recommended.
- Special provisions for kids such as pediatric hospitals, wards, and ICUs, pediatric oximeters, concentrators, and ventilators and strengthening of staff such as pediatricians and pediatric nurses and paramedical workers etc.
- Conducting, at least, part of the election campaign in the online mode, limiting crowds in public spaces, and minimising crowds in offline cultural, political, and political events; as far as feasible.
We all owe it to the common people of Manipur to religiously adhere to the standard SOPS to help prevent/mitigate a possible third wave in Manipur; and, help save our people from possible hospitalisations and deaths.
First published:15 Jan 2022, 9:20 pm
covid-19 pandemicdelta variantomicron IndiaOmicron vs Delta variantomciron symptoms
Debananda S Ningthoujam
The author teaches and studies microbial biochemistry and biotechnology at Manipur University
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