Physician’s Perspective

COVID-19:

Where We Are, Where We Might Be Headed

It’s safe to say that the COVID-19 pandemic has touched the lives of virtually everyone on Earth in one way or another. The consequences of the pandemic have stressed the U.S. healthcare system—including Sentara RMH Medical Center—over the past two years, and multiple surges have taxed hospital resources, as well as our nursing, physician, respiratory and support staff. Recently, increased patient volume caused by the omicron variant, combined with increased staff illness due to community-acquired exposure, have added a whole new level of challenge to our emergency room, operating rooms and hospital staff. Even with declining COVID cases lately, our hospital remains full, and new strategies are being employed to continue delivering highquality medical care to our community. Through hard work, however, we continue to learn about this virus and refine mitigation strategies to prevent its spread, as well as develop therapeutic strategies to treat those infected.

By Robert Garwood, MD Chief Medical Officer

Delta versus Omicron

Both the delta and omicron variants of COVID-19 have led to significant illness, resulting in large numbers of people requiring hospitalization and increased daily COVID-related deaths. However, the two variants feature significant differences in how they have caused their respective misery. While omicron is markedly more contagious than delta, it is generally thought to cause a milder infection, with a risk of hospitalization or intensive care unit admission about half that of delta. Those at greatest risk remain the elderly, the immunosuppressed and individuals with multiple medical issues. The incubation period for omicron is about two days, compared to four days for delta, resulting in a faster onset of symptoms. Unlike previous variants in which fever and cough were the predominant symptoms, omicron tends to present with a runny nose, headache, fatigue, sneezing and sore throat.

Given the faster incubation period of omicron, the course of infection between the two variants also differs. A delta infection appeared to peak in three days, with most people clearing the virus in six days. An omicron infection, which may come with lesser viral loads, appears to peak in two days and clear in a similar time frame.

And while delta infections typically centered in the lungs—likely the reason for the severity of delta infections— omicron is largely an infection of the upper airways. Despite not being as virulent as delta, omicron has resulted in record hospitalizations and death totals that are comparable to delta, due to the sheer number of people infected—even though omicron is lethal in a smaller percentage of cases.

Interestingly, one study showed that although omicron infection seems to provide natural immunity against delta, a delta infection does not seem to provide protection against omicron. This fact all but ensured that omicron became the dominant strain.

As of mid-January 2022, more than 5.8 million Virginians had been fully vaccinated against COVID-19, with 24-25% of that group also having received a booster shot.

Vaccination and Treatments

First and foremost, full vaccination with a booster shot is the most effective way to prevent serious illness and hospitalization from COVID19, regardless of the variant. As of mid-January 2022, more than 5.8 million Virginians had been fully vaccinated against COVID-19, with 24-25% of that group also having received a booster shot. Among fully vaccinated individuals, 2.1% have gotten a breakthrough infection, 0.06% have required hospitalization, and only 0.02% have died. Notably, approximately 85-87% of hospitalized COVID-19 patients have been unvaccinated individuals.

Likewise, unvaccinated people develop COVID-19 infections 4.5 times more than those who are fully vaccinated, and about 2.1 times more than individuals with partial vaccinations. The risks are even more striking when compared to those who also have received a booster shot. Individuals who have received two vaccination shots and a booster have an 80% smaller chance of requiring hospitalization than those who are unvaccinated. Considering all the data, the bottom line is that vaccination with a booster shot is the single most effective way to prevent serious illness leading to hospitalization and death from COVID-19.

In addition to vaccination, several treatment options are available. Unfortunately, previously available monoclonal antibody treatments such as Regeneron have proven ineffective against omicron. However, a new monoclonal antibody treatment, Sotrovimab, is effective against omicron and is available to those individuals at the highest risk for progressing to serious infection. In addition, an antibody treatment known as Euvshield can be given as a preventive measure for immunosuppressed individuals (currently transplant and cancer patients) who cannot adequately respond to a vaccination. Finally, two antiviral medications, Paxlovid and Molnupiravir, have become available to treat infected individuals with a positive COVID-19 test, provided the treatment is given within five days of symptom onset.

Testing and Isolation

Testing has long been thought to be an essential tool in the fight against COVID-19. Particularly with the advent of new therapeutic

modalities, early detection of COVID is necessary to start treatment within the optimal therapeutic window. For omicron, faster replication speed and shorter incubation period result in a much narrower window in which to test for and identify an infection. As such, a rapid antigen test should be performed within two to four days after exposure or immediately upon onset of symptoms, when viral loads are likely high. If initially negative, the test should then be repeated 36 hours later to minimize the risk that the first test yielded a false negative result.

Polymerase chain reaction (PCR) tests are the other option in COVID testing. Although more accurate overall and more likely to pick up infections early, results from PCR tests can take longer to receive (up to two days in most cases) and can remain positive after a person is no longer infectious.

If one were to develop symptoms of a COVID infection, a reasonable testing strategy would be to quarantine for one to two days and take a rapid antigen test after allowing for the viral load to increase to detectable levels. If the first test is negative and symptoms persist, repeat the test in another one to two days. If still negative and symptomatic, consider getting a PCR test, or continue to isolate for five days and then wear a mask for an additional five days. Upon a positive test result, five days of isolation, followed by five days of mask wearing and avoidance of unnecessary travel, are recommended.

The Future of COVID

The question on everyone’s mind today is, “When is this all going to end?” By definition, a pandemic isn’t over until it’s over for everyone everywhere. So vigilance is required here in the United States, and efforts need to continue to vaccinate as many people around the world as possible, to help prevent the development of new variants. In fact, a new subvariant of omicron that spreads about 1.5 times faster than the original has been identified, but at this point does not appear to be evading the protective effects of vaccination or causing increased hospitalizations.

That said, there will likely be new variants seen in the future, resulting in three possible scenarios moving forward. The worst-case scenario would be the rise of a new variant that escapes the protection of both natural immunity and the vaccines and is resistant to current treatments. This variant would likely spread through the population, as with past surges, and cause increased hospitalizations and deaths.

The second scenario would be a new variant that requires a variant-specific booster but is treatable with antivirals and monoclonal antibody treatments; however, given an extremely fast spread rate that causes surging case numbers, neither can be produced fast enough to prevent illness.

The final scenario, which is the best-case scenario, is that COVID-19 variants persist but, as with the flu, a baseline level of immunity will exist and can be augmented with yearly booster shots. In that case, many of those who do get sick will be able to receive effective treatment with monoclonal antibody and antiviral medications.