Post Comes to Premature Conclusions About COVID-19 Omicron Variant Severity

December 10, 2021 antivax, covid19, fauci

SciCheck Digest

It’s not known yet whether the omicron variant causes more or less severe COVID-19 than the delta variant, although some preliminary indications suggest omicron infections might be milder. A Facebook post nevertheless claims, without evidence, that the “toxicity” of omicron is 5 times higher than delta and that its mortality rate is higher.

Tests that detect current infections with SARS-CoV-2, the virus that causes COVID-19, are known as viral tests. There are two types: a Nucleic Acid Amplification Test, or NAAT, and an antigen test.

Many of the NAATs use a molecular biology technique known as the polymerase chain reaction, or PCR, to detect even a very tiny amount of the virus in a specimen.

The PCR test takes advantage of some natural features of biology to essentially scan through all of the RNA present in a sample — such as a nasal swab — and search for the presence of coronavirus RNA.

The Centers for Disease Control and Prevention says NAATs “are unlikely to return a false-negative result of SARS-CoV-2,” and it recommends only laboratory-based NAATS, the most sensitive tests, to confirm infection. It also says saliva tests aren’t as optimal as those using swabs of the nose or nasopharynx (upper throat behind the nose).

An antigen test is designed to detect the coronavirus antigen, a structure on the surface of the virus that triggers an immune response. Also conducted via a nasal or throat swab, antigen tests are less sensitive than NAATs but inexpensive and can usually produce results in about 15 minutes. Getting a result from a NAAT test can take about an hour or even a few days.

Testing can help stop the spread of the coronavirus from those who test positive, because they can then isolate themselves from others. But, as we’ve explained, testing has its limitations. It can take a few days or even longer after exposure to the virus before it’s detectable by the diagnostic tests. So even some with negative results could be infectious.

Still, to help limit the spread, the U.S. has instituted travel requirements and recommendations. All international airline passengers, including U.S. citizens and residents, and those who are fully vaccinated, arriving in the U.S. must show “a negative COVID-19 test, taken within three (3) calendar days of departure, or proof of recovery from the virus within the last 90 days,” as the State Department explains.

The CDC also recommends that everyone, including the fully vaccinated, get a viral test three to five days after returning from international travel.

The CDC recommends that those who aren’t fully vaccinated avoid international travel, and if they must travel, to get a test one to three days beforehand. The unvaccinated also should self-quarantine for seven days after returning to the U.S., even if they tested negative before or upon returning.

International destinations may have their own testing requirements as well.

As for domestic travel, the fully vaccinated don’t need to get tested, but the CDC recommends the unvaccinated follow the same guidelines as those for international travel.

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Since the discovery in late November of a new, highly mutated version of SARS-CoV-2, the coronavirus that causes COVID-19, scientists have been scrambling to learn more about it. First reported to the World Health Organization by South Africa on Nov. 24, the omicron variant has sparked concern across the globe because of fears that it might be able to evade immunity and be more transmissible than the already highly contagious delta variant.

As we’ve reported, the omicron variant contains a worrying set of mutations, some of which are predicted to aid in viral transmission or get around protective neutralizing antibodies. In addition, the variant is spreading quickly in South Africa.

While more information is coming in every day, major questions remain, including how transmissible the virus is and how severe its infections are. Some early evidence suggests omicron cases may be less severe compared with other variants, but it’s too soon to know for sure.

Despite the uncertainty, a popular Facebook post baselessly claims omicron is especially virulent.

“Be sure to wear a mask, because the new COVID-Omicron variant coronavirus is different, deadly and not easy to detect correctly,” the post misleadingly reads, before going on to list symptoms it claims are of the variant.

“Of course, the toxicity of COVID-Omicron is 5 times higher than that of the Delta variant, and the mortality rate is also higher than that of Delta,” the post continues, adding that omicron is “highly harmful, the virus is highly virulent, and the fatal rate is high.”

It also states, without evidence, that the omicron “wave … is more deadly than the first wave of Covid-19.”

Omicron Severity Unknown, But Possibly Reduced

As we’ve explained before, it’s still too early to tell if the omicron variant is more or less virulent than delta, let alone to put a quantitative estimate on it — and any accurate assessment of severity will take some time. But there are some signs that omicron infections might be less severe.

Dr. Angelique Coetzee, chair of the South African Medical Association, and a physician who has been treating some of the early omicron cases in that country, has told multiple news outlets that omicron cases so far appear to be very mild, with an unusual presentation that is mostly limited to extreme fatigue, body aches and pains, and headache.

Some of her comments, including the idea that patients do not seem to have a severe cough, may be the origin of some of the symptoms listed in the post.

It’s hard to know, though, whether this is fully representative or will change in the future. As of Nov. 28, the WHO has said that there “is currently no information to suggest that symptoms associated with Omicron are different from those from other variants.”

According to a Dec. 4 report on the first set of likely omicron cases at Steve Biko/Tshwane District Hospital Complex in Pretoria, South Africa, fewer patients have needed supplemental oxygen than before, and more cases are what physicians there are calling “incidental” cases, or instances of COVID-19 that were detected in people who were found to be infected when they underwent the required testing for hospital admission, but were admitted for another reason.

The overall in-hospital death rate is also lower — 6.6%, over the past two weeks, compared with 17% over the past 18 months.

“It’s too early to be able to determine the precise severity of disease,” Dr. Anthony Fauci, the director of the National Institute of Allergy and Infectious Diseases, explained in a Dec. 7 coronavirus briefing, in reviewing the existing evidence on the topic. “But it appears that with the cases that are seen, we are not seeing a very severe profile of disease.”

“It might be — and I underscore might — be less severe, as shown by the ratio of hospitalizations per number of new cases,” he continued. “However, this could be influenced by the fact that many in this particular cohort are young individuals. The hospital stay seems to be less and the use of supplemental oxygen needs to be less. Again, I caution you. These are still preliminary.”

Because hospitalizations and deaths are lagging indicators, Fauci said, it would likely take “at least another couple of weeks” before scientists have a “good handle” on the relative severity of omicron, and “a few weeks thereafter” to have a “really good handle” on the subject.

Another issue making it difficult to tell whether the apparently less severe cases truly reflect a drop in the virus’s virulence is COVID-19 immunity in the population, either from previous infection or vaccines. South Africa has a relatively low vaccination rate, but some experts estimate that almost all South Africans have already had COVID-19. If that’s the case, then it could well be that the reduced severity reflects the fact that most people are already largely protected from severe disease, even if they are susceptible to reinfection with this variant.

Misleading Claim About Diagnostic Testing

The Facebook post also baselessly claims that the omicron variant is “not easy to detect correctly” and suggests that cases of the variant are difficult to diagnose with current tests.

“The result of nasal swab test for COVID-Omicron is usually negative, and the number of false negative cases of nasopharyngeal test is increasing,” the post reads.

There is no evidence that the omicron variant is causing COVID-19 tests to fail on any large scale. Dozens of countries around the world have been able to identify omicron infections by sequencing the viruses present in specimens that have tested positive with existing diagnostic tests.

“The widely used PCR tests continue to detect infection, including infection with Omicron,” the World Health Organization said in its Nov. 28 update on the variant, referring to polymerase chain reaction tests that check patient samples for the presence of SARS-CoV-2 genetic material.

The Food and Drug Administration has warned that one particular PCR test authorized and used in the U.S. is expected to be unable to detect the omicron variant, since the test only looks for one short stretch of the viral sequence, and omicron happens to have a deletion in that spot.

But the test is just one of many available molecular tests — the agency has authorized 267, as of Dec. 9 — and is not thought to be used for high-volume testing. (The FDA identified one other authorized PCR test that would be affected, but it hasn’t been distributed to anyone.) PCR tests that check for other parts of the viral genome or at multiple different spots are not expected to have problems identifying omicron infections.

As we have explained before, many omicron viruses have a deletion in the S, or spike, gene, that affects a few popular PCR tests. But it’s turning out to be a feature rather than a bug.

Because of the deletion, many omicron samples won’t test positive for the S gene — unlike with most delta samples — but are positive for the other two gene targets. This means the test still works to diagnose omicron patients, while at the same time flagging potential omicron cases.

As the WHO writes in its Dec. 7 weekly epidemiological update, this “S-gene target failure (SGTF) can be used as a marker suggestive of Omicron,” although the agency says sequencing should be done to confirm that, since other variants are known to have the deletion.

While evaluations are continuing, there is also no evidence to indicate that more rapid but less sensitive antigen tests, which look for the presence of viral proteins in a sample, are unable to detect omicron infections.

The WHO’s update notes that preliminary evidence from labs “independently confirms” that antigen tests can accurately diagnose omicron infections, and that as of Dec. 7, “there have been no reported misdiagnoses (false negative results)” for any WHO-authorized diagnostic test because of the omicron variant.

South Africa’s Coetzee, in her interview with Canada’s Global News, also said that antigen tests were “definitely” still working against omicron, although she cautioned against testing too soon once symptoms develop.

Post Correctly Urges Caution, But Forgets Vaccination

While much of the post is unsubstantiated, particularly its claims about disease severity, it urges readers to be cautious of the new variant.

“Please be careful, avoid crowded places, keep a distance of 1.5m even in open places, wear a double-layer mask, wear suitable masks, and wash your hands frequently when everyone has no symptoms (coughing or sneezing),” the post reads.

Those are all recommended precautions that public health officials are emphasizing to protect people from both omicron and the still-dominant delta, so that’s good advice.

It’s worth noting that even if omicron infection results in less severe disease, if it’s more transmissible, it could still end up hurting more people.

“If they’re allowed to spread unchecked, even though they’re not individually more virulent or lethal, they just generate more cases, they put pressure on the health system and more people die,” Dr. Mike Ryan, executive director of WHO’s health emergencies programme, said of coronavirus variants during a Dec. 8 press conference.

The post, however, doesn’t mention vaccination, which is the single best way to protect yourself against COVID-19.

“The single big message, if you are offered a vaccine, please get that vaccine,” said Ryan. “It doesn’t matter what variant you’re doing it for.”

Editor’s note: SciCheck’s COVID-19/Vaccination Project is made possible by a grant from the Robert Wood Johnson Foundation. The foundation has no control over FactCheck.org’s editorial decisions, and the views expressed in our articles do not necessarily reflect the views of the foundation. The goal of the project is to increase exposure to accurate information about COVID-19 and vaccines, while decreasing the impact of misinformation.