There is much good news in regard to COVID

Dr. Bradly Bundrant

There are now federally authorized oral medications for the early treatment of COVID. The drug manufacturers Pfizer and Merck each have newly authorized drugs which interfere with the production and processing of proteins that make up the different parts of the virus. When a cell is infected with SARS CoV-2, the virus that causes COVID-19, the viral RNA instructs the cell’s ‘protein making machinery’ (known as a ribosome) to go into action. In this process the RNA strand is read, and two viral protein molecules are produced. These are then cut into different pieces by viral enzymes called proteases, and the pieces assembled to make a new viral particle.

Dr. Bradly Bundrant is the chairman of the Health & Wellness Coalition of Runnels County. The coalition is gearing up to start hosting health screenings, public education classes and podcasts.

Paxlovid is the brand name of the Pfizer drug, and it is the first oral medication authorized by the FDA for treatment of COVID-19 since the EUA (Emergency Use Authorization) for hydroxychloroquine was revoked on June 15, 2020. Paxlovid was studied in a group of subjects equally divided into treatment and control groups. There were 10 COVID deaths in the control group, and none in the treatment group. There was also marked reduction in hospitalizations (almost 90% fewer), and there were no serious side effects. Paxlovid actually is a combination of two medications, nirmatrelvir (PF-07321332) and ritonavir (currently part of some regimens used to treat HIV). Paxlovid is authorized for use by persons who contract COVID and are at high risk for severe disease. These drugs are protease inhibitors that interfere with the cleavage of viral protein molecules and thus prevent the assembly of new viral particles.  They are in separate tablets that are to be taken together twice daily for 5 days beginning as soon as possible after diagnosis of the disease.  It is not to be prescribed to hospitalized patients, though patients taking the drug at the time of admission may continue with their course of treatment, and it is not to be used in patients under 12 years or 40 kg. (or 88 lbs.). 

Molnupiravir is a drug which was being developed for seasonal flu, marketed by Merck, and it received an EUA for use in COVID one day following the EUA for Paxlovid. Molnupiravir is known as a nucleoside analog, which means that it works by creating a ‘counterfeit RNA building block’ for viral RNA which results in faulty transcription, thus interfering with the propagation of the virus. The evidence for effectiveness is not as compelling as for Paxlovid. Evidence is limited to one Phase III trial, and in that trail with roughly equal numbers in each group, the control group had 9 deaths and the molnupiravir group had one. The hospitalizations were 64 to 45 in favor of treatment and the clearance of virus from the nose was faster with treatment. There were no significant drug related side effects. Like Paxlovid, it is taken twice daily for 5 days and it is not to be prescribed for patients who are in the hospital, but patients how are on the drug may continue with their course if they require admission to the hospital. It is not to be used in anyone younger than 18. The FDA has advised that this drug should be used only if other authorized treatments are unavailable or contraindicated.

More good news is that we now have at-home antigen testing (although supplies are constrained at times). The first thing to know about antigen testing for COVID is that a positive test is solid evidence that the person can infect other people with COVID, whether that person feels sick or not. No test is 100.000% accurate, but when this test is positive that is proof beyond all reasonable doubt. A negative test, on the other hand, may be wrong 10 to 20% of the time. For that reason these tests come in sets of two, along with the instructions that a negative test should be repeated in 24 to 36 hours. One of the foundations of laboratory testing is that every test has a false negative rate, that is the test result will sometimes be negative when the condition or disease is actually present. However, if a second independent test is also negative, the chance that both will be false negatives is the likelihood that the first test will be, multiplied by the likelihood that the second test is also a false negative. For illustration purposes we will say that the false negative rate is 15% or 0.15. (The test’s sensitive is 85%.) By repeating the test 24 to 36 hours later, the two test results are independent and the likelihood of both being falsely negative is (0.15x0.15=0.0225) or a little more than 2%. That’s the chance that someone who is infectious with COVID will test negative on two consecutive days, using an antigen test with 85% sensitivity, and that is deemed to be an acceptable risk of missing a case of COVID in the general population. Using these tests there are some circumstances in which people can return to work more quickly after recovering from COVID. Right now this reduced isolation period is limited to health-care workers. They can return 7 days after the onset of symptoms or a positive test, if they have no fever or other symptoms, and they are negative by an antigen test. The CDC also says healthcare workers do not need to quarantine following high-risk exposures if they have received all recommended vaccinations, including a booster. Masking is required in healthcare settings, and that also limits the infectivity of anyone who might be asymptomatically carrying the virus when they return to work in these settings.

As to Omicron, this is the biggest change we have ever seen in COVID. Except for people whose immune system is hyper-aroused, due to recent infection or vaccination for example, everyone is about equally at risk of contracting this variant. Therefore, it is difficult to interpret reports that severe disease is less common with this variant. Suppose a population where 70% of the population has immunity from vaccination or prior disease, and would be safe from the alpha variant, is exposed to Omicron. If they all get the disease we would expect 70% to have milder disease because of their preexisting immunity. On the other hand, there is no reason to expect that Omicron causes worse disease. There is some evidence of decreased activity in lung tissue, and decreased intracellular activity could mean less inflammation and less severe disease.

Finally, I give you this hopeful prediction: This will be the last major wave of COVID.

After the winter of 2021-22 we will have cold, flu and COVID season. We already have strains of cold virus that can be very serious for certain groups, such as RSV (Respiratory Syncytial Virus) which can cause life threating pneumonia in infants but causes only a bad cold for most adults, and COVID will be similar.

This article is intended to provide general information only, and is not to be taken as medical advice. For advice about a particular case or situation, consult your own physician or other trusted health professional. Dr. Bundrant is the designated Health Authority for Runnels County, and the President of the Health and Wellness Coalition for Runnels County. You can follow the Coalition on Facebook or learn more about the Coalition and find more of Dr. Bundrant’s articles on the web at www.hawc4rc.org.