Omicron Variant Found in 4 in NCCo but Delta Still Dominant; DPH says Winter Surge Underway

The Delaware Division of Public Health (DPH) today announced that it has confirmed the first four cases of the Omicron variant (B.1.1.529) among Delaware residents. The variant was detected today through routine sequencing of test specimens by the Delaware Public Health Laboratory.

The four cases involve two adults in their 30s, a teenager and a child under the age of 10, all residents of New Castle County. Two individuals were fully vaccinated and two were unvaccinated. None of the individuals had a known history of travel. Case investigation and contact tracing to identify, inform and monitor anyone who was in close contact with these individuals is ongoing.

The Omicron variant has been classified as a Variant of Concern by both the World Health Organization and the Centers for Disease Control and Prevention (CDC). This variant was first reported in South Africa and has since been detected in more than 70 countries and at least 35 states, including Delaware, in the United States. Virus mutations are common. Preliminary data suggests the Omicron variant may spread more easily and quickly than previous variant strains of the virus.

The Delaware Public Health Laboratory and other laboratories regularly monitor for the presence of COVID-19 variants, including Omicron, through routine genomic sequencing of test specimens. Genome sequencing is a public health surveillance tool used to monitor the prevalence of COVID-19 variants; it is not used to diagnose individuals with a specific strain of COVID-19, as treatment recommendations do not differ based on variant strains. COVID-19 tests identify current infection of COVID-19, but do not identify a specific variant of the virus the individual might have.

“With cases of the Omicron variant detected in our surrounding states, it was only a matter of time until we detected this variant in Delaware,” said DPH Director Dr. Karyl Rattay. “We are closely watching the science around this new variant. While it is encouraging that most individuals infected with this strain have reported minor symptoms, we still have a lot more to learn about Omicron. Therefore, we need to do what we know works to combat all strains of COVID-19: get vaccinated, get tested when appropriate, wear a mask in indoor public settings, socially distance from others and wash your hands regularly.”

Dr. Rattay said boosters may play a significant role in fighting the variant. Early results from both Pfizer and Moderna are pointing to booster doses being much more effective against the Omicron variant than having two doses alone. However, Pfizer is showing up to 70% effectiveness against serious illness leading to hospitalization after just two doses of the vaccine. 

DPH has seen a significant rise in new positive cases over the past month, indicating a winter surge.  Delta remains the dominant strain circulating in Delaware and the United States.

“While rising cases are a significant cause for concern, the public should understand that we have the public health tools in our toolbox to continue to fight this virus,” said Rattay. “Our data continue to show that new positive cases and hospitalizations are predominantly occurring among those who are unvaccinated. Vaccines remain the most critical tool to protect us against severe disease.”

Delawareans who are fully vaccinated have significant protection from COVID-19 infection, serious illness and death. Delawareans who are 5 years and older who have not received the vaccine should do so as soon as possible. This is especially important for the youngest eligible Delawareans, as they currently have the highest COVID-19 case rates. Visit for a list of vaccine locations.

DPH also encourages those who have been vaccinated with at least one dose to complete the full vaccination series and everyone 16 and older should receive a booster dose when eligible. Boosters increase the strength of your antibody response to protect you from the virus, and many of its mutations. All adults who completed a primary vaccination series with an mRNA vaccine at least six months ago and those who received a Johnson & Johnson shot at least two months ago are eligible for a booster. For more information about booster doses of the COVID-19 vaccine, visit

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