Omicron is contagious, not a mild infection–experts

Some experts said this latest variant called omicron (or B.1.1.529) of Covid-19 may have been lurking around for months even before it was discovered, as reported by The Associated Press.

Well, one thing that is true is that this dangerous variant quickly spread like wildfire around the world after the first sample was collected in Botswana, South Africa. A piece of good news, however, was that Omicron is thought to be less severe compared to other strains, says the US Centers for Disease Control and Prevention (CDC).

Weighing in on Omicron

FOR its first episode of the year titled “Omicron: What We Should Know & What We Should Do,” the webinar organized by the University of the Philippines, in partnership with the UP Manila National Institutes of Health (NIH), National Telehealth Center and with the UP Philippine General Hospital, discussed how people should know if it is really Omicron and how best to react to it.

According to Dr. Franco Felizarta, an Infectious Disease and Internal Medicine Specialist of the UP Medical Alumni Association in America (UP-MASA), Omicron has spread to over 150 countries in a span of just two months, with over 50 mutations, 30 of them in the spike gene, with at least 25 unique to this variant. Compared to other mutations, normally with two to four of the most important mutations, Dr. Felizarta said Omicron has seven of these.

He said that whenever there are mutations, at least four things are asked: transmissibility, disease severity, risk of infection, which means breakthrough infection or vaccine efficacy, and impact on diagnostics. He said there is no direct evidence yet as to its transmissibility but by just analyzing its mutations, Dr. Felizarta said Omicron is as transmissible as Delta, with a potential for immune escape. “If both are present, there is going to be a high infection growth rate.”

As for Omicron’s disease severity, Dr. Felizarta said this is not yet known since clinical data are still under review. With regard to risk of infection, preliminary evidence suggests possible increased risk of reinfection. For impact on diagnostics, RT-PCR continues to detect Omicron. “When using antigen test, there’s a lot of false negative on the first two days after the first positive RT-PCR test but after two days, it becomes very active. However, there’s a need for another study to confirm this,” he said.

He said they already knew Omicron would be trouble since it spread rapidly across South Africa and appears to have out-competed other previous variants. Compared to Delta, Dr. Felizarta said Omicron, in a study done in Hong Kong last month, multiplies 70 times more quickly in the human bronchus, the large airway that connects the windpipe to the lungs, but replicates 10 times slower in the lung tissues.

In terms of symptoms, he said there’s really no difference between Delta and Omicron because Omicron will infect vaccinated persons and those with previous infections so there will be less severe symptoms.

Managing the ‘holiday’ surge

MANY are calling it already as the Omicron surge, but Dr. John Wong, an epidemiologist and Senior Technical Adviser for Epimetrics, Inc., said it can be called a “holiday surge.” He believes it was caused by several events like holiday gatherings by family and friends outside of their “bubble” or their residences. Next is imported infections, mostly from those who came overseas, then the presence of Omicron, touted as a more infectious variant, plus instances of people supposed to be in quarantine or isolation have gone out, and then uneven vaccination rates or highly concentrated vaccination on the National Capital region (NCR) and much less everywhere else, he said.

So, is this Omicron? Dr. Wong said Omicron may have been detected in sequencing but from small, nonrandom samples. “The holiday surge bears the same signature as those in other countries with more sequencing: there’s steep, rapid spike, doubling time of only two days compared to Delta’s two weeks, with rise in hospitalization and deaths not proportional to the Delta wave.”

Contrary to what others were saying, Dr. Wong said Omicron poses risks to individuals. It is not a mild infection since patients are being hospitalized, the unvaccinated are still at risk, and long Covid may still result. And some people think that Omicron can be a natural vaccine, which he said it is not because it is a virus. “Unlike vaccines, the dose of the virus or the viral load cannot be adjusted. If you get too little of the viral load, you don’t develop immunity at all; if you get high a dose, you get hospitalized. Since it’s infection, you can get severe disease, and infected patients can transmit the virus.”

How to avoid it? Dr. Wong looks to apply the reverse of what caused it, which is to avoid super spreader events, widespread use of antigen tests, affordability of new anti-Covid pills, home care for mild cases, and doubledown on vaccination for the elderly, the unvaccinated, and booster doses. As control measures, Dr. Wong is looking at imposing various levels of community quarantine, reduce contact rate between people to reduce transmission rate; apply testing, contact tracing and isolation/quarantine; and encourage behavioral change in the public to become more adherent to minimum public health standards.

Take action vs Omicron

BECAUSE the Covid-19 variants have several different features, there should be enough agility when crafting a response, according to Dr. Anna Ong-lim, Professor and Chief of the Division of Infectious and Tropical Disease at the Pediatrics College of Medicine, UP-PGH.

Dr. Ong-lim said that now everyone knows Omicron is highly transmissible, but “our response should be tailored to the variant’s features, which is not really different from what we have been doing before and still being advocated by public health authorities,” Dr. Ong-lim said.

She also called for ramped up vaccination particularly in the countryside in order to achieve widespread protection. “If we are seeing the impact of the variant on the NCR, which already has good vaccination coverage, what more if this variant reaches other regions where vaccination is low,” she emphasized.

Also being eyed for improvement is the review of current masking requirements since there are countries where wearing of masks is highly politicized, unlike here in Asia where masking is generally accepted. There are recommendations now to re-examine and optimize mask fit and filtration, and reinforce proper wearing.

She also called for the continued observance of isolation, quarantine and physical distancing, and policies on the isolation and quarantine guidelines are still being reviewed and finalized by the Department of Health.

Dr. Ong-lim also sees the testing strategy to change to “Isolate” first then “Test/treat.” “We might want to consider high priority for testing for those at risk of developing severe disease or the symptomatic ones in a closed setting, and de-prioritize the asymptomatic ones and those with no known risk of exposure.”