SP is a 60-year-old male with history of hypertension, hyperlipidemia, morbid obesity and diabetes who came to the ER with progressively worsening dyspnea and fever of 102 °F. He was found to be in acute hypoxic respiratory failure due to COVID Pneumonia. On further discussion with his family, I learned that he had gotten the Pfizer vaccine and recently received the booster shot. Upon hearing the news, the patient’s family asked “How can he have COVID when he is already vaccinated?” This is a common concern shared by many patients and their family members.
In this article, I explore the current research and offer my insights on the effectiveness of the Pfizer vaccine against the Omicron variant. In November 2021, the Omicron variant emerged in South Africa and a month later became one of the dominant variants in the U.S. Interestingly, studies have shown that it is much more transmissible than the Delta variant and the original COVID strain. One of the most common symptoms reported by patients is sore throat. Initial studies had revealed that the omicron virus is able to bypass antibody neutralization by the Pfizer vaccine.
A study conducted by Discover Health analyzed the effectiveness of two doses of Pfizer vaccine against hospitalization for COVID in South Africa. The study showed that the two doses of Pfizer vaccine were 70% effective against hospitalization with Omicron (1). It is important to note that antibodies can wane over time, but the booster vaccine can increase antibody production and further boost immunity (2). Further studies are being conducted to determine the duration of this effectives conferred by the third dose.
From my personal experience, patients who have been vaccinated are hospitalized for fewer days and are successfully weaned off oxygen prior to discharge. DP was in the hospital for 3 days and was discharged home after being treated with Remdesivir and Decadron. I have seen many young unvaccinated patients with no pre-existing conditions requiring HFNC or even intubation and subsequently getting tracheostomy and PEG. The quality-of-life after hospitalization between these two patient groups is drastically different.
Current CDC guidelines recommend that everyone older than 5 years can be vaccinated and boosters are recommended for those older than 16 years (3). I recommend patients and their families get vaccinated with COVID vaccines. This would not only protect your friends and families, but also protect those who do not have access to vaccines and will significantly reduce the spread of omicron. One recommendation that I make for those who are taking international trips is to get the third booster dose at least three days prior to traveling. In fact, CDC recommends not to travel internationally until you have been fully vaccinated.
There is still a lot of research that needs to be done to determine the true severity of Omicron compared to other variants (4). One thing that still holds true is that masks, social distancing and hand hygiene continue to offer the best protection in addition to vaccines.
1) https://www.nejm.org/doi/full/10.1056/NEJMc2119270
2) https://www.nejm.org/doi/full/10.1056/NEJMc2119358
3) https://www.cdc.gov/vaccines/acip/meetings/downloads/slides-2021-12-16/06-COVID-Scobie-508.pdf
