A few months ago, we were anticipating the reopening of civil society. But events intervened. First, the protection of two-dose vaccines started to subside. Second, unvaccinated patients, including children, were sickened by the furiously infectious Omicron variant of SARS-CoV-2. More patients survive the Omicron virus than Delta, many experts say, but there are so many sick children and adults that the medical system has still been overwhelmed. Nursing and other medical staff are exhausted, and patients with other diseases or conditions may not get the treatments they need.
On January 6, in New York, the number of people with positive tests was 22.5 percent; in Connecticut, 29.1 percent, and in Massachusetts, 21.8 percent. By the time you read this, these numbers will be higher. Infections do not go on indefinitely; eventually there will be no uninfected or unvaccinated people. Epidemiologists, or rather the clan of mathematical modelers among them, predict a crash in the number of infections by early February 2022. That may signal herd immunity and a change from pandemic status to endemic. The latter causes sporadic infection at low levels and tends not to overwhelm hospitals or harm the economy. That said, no one rules out new variants.
Omicron appeared in Botswana and South Africa in November 2021. South African physicians have seen mild disease, and the infection is declining there. In the UK, one report said severity is unaffected; others that the disease caused by Omicron is milder than the one caused by the Delta variant. The CDC’s Morbidity and Mortality Weekly Report appears every Thursday. It provides no conclusions yet on the severity of Omicron on unvaccinated people, including children. Vaccinated people do much better. Deaths do not seem to be increasing as rapidly as infections. In the early stages of a new infection or treatment, information comes in press reports, which can be written with more enthusiasm than data.
There are about 50 mutations in the Omicron virus and a dozen in the Delta variant. A virus enzyme copies the RNA genome of SARS-CoV-2 but makes errors — 30 have accumulated in the Omicron spike protein and 20 in other omicron genes. Think of them as typos that the virus has not corrected. If the typos help the virus survive counterattack by the immune system, the typos (mutations) are retained by natural selection. Each infected lung cell makes thousands of viruses, so the infection spreads fast. Since November, Omicron, which makes about 5 times more virus than the original virus, has nearly replaced the Delta variant in some places.
You may wonder how any living thing survives viral onslaughts; the answer is that sometimes they don’t. When we do survive, it is because the human immune system is a wondrous collection of rapid defenses. Immunology is the science of engaging these defenses before a pathogen does. The pathogens evolve and they usually have ways to suppress the counterattack of the host. Immunity is as complicated. I taught in a course called The Cell Biology of Tissues and Organelles for beginning medical and dental students for 25 years. Immunology flummoxed but fascinated the students. It takes time to learn and in the beginning is hard to believe.
What is the scientific and medical community doing about Omicron? In the days of Ebola (remember that?) the response was a failure. With no licensed vaccine, there was a poor response by WHO and other health agencies. An organization called CEPI (Coalition of Epidemic Preparedness Innovations) was formed to create and deliver vaccines to middle- and low-income countries. CEPI now has partners, and they are delivering vaccines. The organization is ambitious and wants to create variant specific vaccines in 100 days.
A group from Baylor College of Medicine and The Texas Children’s Hospital has fashioned a vaccine that does not employ an mRNA, but rather fragments of viral protein. The vaccine, called Corbevax, does not require refrigeration; a dose costs $1.50 and is not patent protected. It has been approved in India and is being manufactured in huge numbers. It is made using an older method, but sometimes that is best. A recent issue of Nature has a fine review on the status of COVID vaccines written for non-scientists.
Treatments are being developed that stop infections, including immunoglobulins that can be inhaled or injected. In the same vein, nanobodies, tiny antibodies made by camelids (alpacas, camels, and llamas) neutralize Omicron or other viruses. Think of an asthma inhaler spraying antibodies directly onto the virus in your lungs. There is a recent video from the Yale School of Medicine that explains this method.
Drugs to inhibit virus replication are a recent development — in the 1990s for HIV and now for other viruses. Pfizer has a drug called Paxlovid, which blocks the cleavage of viral proteins into functional units. It is highly effective early after symptoms of COVID have appeared. Omicron works fast, so the drug must be administered in the first three days of an infection. There are limited supplies and the drug is tricky to make, but it will be in use shortly.
The Merck drug Molnupiravir blocks the enzyme that copies the virus genome. Molnupiravir is less effective than Paxlovid, but interesting (to me) because it works against other RNA viruses. These include influenza, RSV or respiratory syncytial virus (a major cause of ER visits by children); norovirus (think cruise ships); Chikungunya (a mosquito-born virus that causes severe joint pain); Venezuelan equine encephalitis; and hepatitis C. Perhaps we are at the beginning of a new era in antiviral drug therapy.
In the meantime, the best thing to do is get the vaccine and booster, which are now available for 5–12-year-old children. Vaccines for 1–5-year-olds will probably not be available until late spring, according to Dr. Bill Moss of Johns Hopkins. Let’s see if the epidemiologists are right and the peak of infections comes soon. Watch positivity levels, which indicates infection but not necessarily symptoms. Watch hospital admissions. Watch deaths from Omicron and Delta. And hope for the best.
Rich Kessin is Emeritus Professor of Pathology and Cell Biology at the Columbia University Irving Medical Center. Email Richard.Kessin@gmail.com. For predictions on what will happen in 2022 and on case levels, vaccination levels, and deaths, see The Johns Hopkins University Data tracker or watch the University’s most recent briefing. Sign up for their weekly newsletter on this site.
