Is it really the COVID killer they say it is?
CLINICAL MATTERS
As more and more local cases of Omicron are reported, it is very likely that it is driving the exponential increase in cases. Community transmission is confirmed when it is no longer possible to trace individual cases to distinct clusters or imported cases. This confirmation is a retrospective exercise and is usually demonstrated only several weeks after the fact. The overall behavior of the current infection curve—steep rises, but mostly mild and asymptomatic cases—suggests that Omicron is taking over. Omicron seems to have a survival advantage over the Delta variant, and it is expected to become the dominant variant very quickly.
More and more laboratory and clinical studies are showing that Omicron is a milder virus than Delta. Data from the UK categorically shows that Omicron is associated with three-fold less risk of hospitalization compared to Delta. Vaccines continue to decrease the risk of severe disease for Omicron, and boosting with a third dose increases this protection against hospitalization. The propensity of Omicron, however, to spread quickly can overwhelm healthcare systems if proper triaging of the more severe cases for admission is not followed. If large numbers of healthcare workers are infected at any given time, these can also severely impact the ability of hospitals to function.
In places with high vaccination rates like Metro Manila, recent breakthrough infections have been generally very mild despite the large numbers of new cases. Since the start of vaccination efforts this year, 85 percent of hospital admissions and 93 percent of deaths have been among the unvaccinated.
With Omicron being milder than Delta, most fully vaccinated people with breakthrough infection with Omicron will develop asymptomatic or mild disease. In countries that were hit early on with Omicron, fully vaccinated patients at high risk for complications who developed breakthrough infection are barely developing respiratory symptoms, let alone pneumonia.
In my medical practice, the last four patients I admitted were all fully vaccinated and two of them were boosted. All were positive on RT PCR, but their chest x-rays were all clear. One patient had a chest CT scan (which is more sensitive than xray) and it was read as no pneumonia. These patients were all high risk with comorbidities. They got admitted not because of COVID-19 symptoms but because of their comorbidities. Their ferritin levels and hsCRP, which are markers of inflammation and predict severity, were all near normal. These findings are all consistent with what has been reported about Omicron infection. In contrast, my patients during the Delta wave showed ravaged and burnt-out lungs, ferritin, and hsCRP levels many times elevated, and many deaths and much disability.
This does not mean that Omicron is not capable of severe disease, particularly in those who have not been vaccinated. While some have called Omicron a “natural vaccine,” this is a dangerous assumption. Omicron is not a vaccine. It is a virus, which can still kill vulnerable patients. COVID-19 infection, whatever variant causes it, still comes with increased risk of blood clotting and myocarditis (inflammation of the heart muscle). Unlike vaccines which are either pieces of the virus or dead virus and cannot infect other people, natural Omicron infection can be passed on to other people who in turn may end up with severe disease.
There are also those who call Omicron the “beginning of the end of the pandemic.” While it would be great if this were the case, COVID-19 has thrown many curve balls just as the world thinks it is winning. Moreover, the more infections with Omicron occur, the more chances it has to mutate into yet another variant and to restart the cycle all over again.
As if to underline this possibility, another sensationalist piece of news proclaimed a new “variant” known as IHU spreading in Europe as the next variant of concern. A quick fact-check revealed IHU to be lineage B.1.640.2. The mother strain of this lineage, B.1.640, is designated as a variant under monitoring and while it has scary-looking mutations, there is as of now no evidence this causes the virus to be more transmissible, deadlier, or able to dodge our current vaccines. Nevertheless, even if this piece of news turned out to be fake, the threat of emergence of new variants is real.
So how is this going to play out? If we are lucky, the Philippines will follow the trajectory of South Africa. Omicron caused a very steep risk in cases, then started to burn out after four weeks as it likely ran out of susceptible hosts. South Africa has a lower vaccination rate than the Philippines. The rise in cases was quite brisk, but the rate of hospitalization and deaths were much milder compared to their Delta wave. This is the scenario for which everyone is praying. With high vaccination rates in Metro Manila and high compliance with masking, there is a good chance we will see even fewer deaths than South Africa. Omicron burning itself out, however, is not a guaranteed outcome. The US and France are setting all-time highs in numbers of cases without any signs of slowing down. We cannot assume that we will follow the best-case scenario. Instead, we need to hedge by tightening our prevention, detection, isolation, treatment, and reintegration strategies. Temporary curbs on gatherings and mobility, along with boosting will increase the odds of a short and quick Omicron wave.
With widespread vaccination and a milder variant, COVID-19 may already be in the process of turning into the common cold. Without vaccines, this would have been a very, very different story, even for Omicron. Vaccines have changed the equation. Even amid the rapid increase in cases, there is hope that if we play our cards right, we will be okay. Whether it is the end game or yet another bump in the road, we aren’t helpless and we will cope.