Based on some recent studies, it looks like Omicron has difficulty getting past our body’s T-cells. In test-tube studies, researchers in South Africa exposed copies of the virus to T cells taken from people who received either the Pfizer Vaccine or the Johnson and Johnson vaccine or those who had not been vaccinated but had developed immunity from a previous covid infection. This study concluded that T-cell immunity to Omicron from either natural immunity of the prior infection or vaccines is well-preserved.
Based on a study published in the NEJM, 2 shots of the Pfizer vaccine prevent most people from being hospitalized with the Omicron variant of COVID. The data shows that the effectiveness of two-doses against Omicron did slightly drop compared to delta but overall remains effective at about 70% at preventing covid hospitalizations.
Yes, Omicron has been found in several studies to cause many more infections in vaccinated and boosted and, of course, those who are unvaccinated as well. In South Africa, most of the hospitalizations occurred among the unvaccinated. The rates of Covid hospitalization during the Omicron timeframe were lower than the delta timeframe. Hospitalization rates were anywhere from 2-to-6 times lower during the Omicron period, depending on age.
Why is this the case? There are 2 main factors at play. One is that there are higher vaccination rates during the omicron timeframe. Two, the lower average age of those becoming infected during the omicron timeframe means young adults make up a higher percentage of hospitalizations than before. So these two factors are known as confounding variables which muddies the water when trying to figure out if Omicron is truly a milder infection than delta. So is the Omicron variant itself less dangerous than delta? Even as we enter 2022, that is unclear.
Doctor Mike Hansen, MD
Internal Medicine | Pulmonary Disease | Critical Care Medicine
Contact and Social Media Links: https://doctormikehansen.com/contact/