The Omicron variant and its various subtypes are the dominant forms of SARS-CoV-2 in the U.S. as of August 2022.
Protection Against Omicron
There is evidence that existing two-dose vaccine regimens are less effective against Omicron than they were against Delta and the original coronavirus. However, booster shots can help restore protection. A January 2022 study of over 300,000 people showed that an mRNA booster shot was 90% effective against hospitalization with Omicron.
More recent research contains more good news. A March 2022 study from 21 U.S. medical centers found that a three-dose mRNA vaccine regimen could reduce both the chances of ventilation (an extreme form of care) and of death from Omicron by 94%.
While protection is still high, it can wane over time. A CDC study published in February 2022 showed that 2 months after the first shot vaccines were 90% protective against hospitalization. Four months after the third shot, that protection dropped to 78%. (This data was collected during the Omicron wave in early 2022.) The best course of action, per the CDC, is to get vaccinated and get your booster if you are eligible.
Protection Against BA.5 (Omicron subvariant)
The Omicron subvariant BA.5 is the dominant form of the SARS-CoV-2 virus in the United States and is potentially the most contagious strain of the virus to date. (The latest breakdown of variant proportions is available on the CDC website).
Symptoms for BA.5 are similar to the earlier version of Omicron including cough, runny nose, sore throat, fatigue, headaches or muscle pains. Patients are more likely to present with upper respiratory infections and less likely to lose their senses of taste and smell or experience shortness of breath.
Vaccines provide durable protection against severe illness including hospitalizations and deaths and limited protection against symptomatic disease caused by Omicron and its variants. Boosters help restore protection against symptomatic disease, although it wanes within months of receiving them.