Vaccine, booster still best defenses to both Delta and Omicron variants

Published on Monday, December 13, 2021

By: Ruth Cummins, ; Annie Oeth, aoeth@umc.edu

As Mississippi cases of COVID-19’s Omicron variant grow, experts say some things won’t immediately change: The Delta variant remains the overwhelmingly predominant strain in the state, and getting vaccinated and boosted is the best way to protect against serious infection.

“There are a lot of questions related to transmission, how effective the current vaccines will be, and whether there will be any different symptoms,” said Dr. Bhagyashri Navalkele, assistant professor in the Division of Infectious Diseases and medical director of infection prevention at the University of Mississippi Medical Center.

But for now, Navalkele and other experts say, “all adults 18 years and above who are eligible to receive booster shots should go ahead and receive it without any delay to improve immune response against ongoing Delta variant and emerging Omicron variant.”

Compared to the original SARS CoV-2 virus, Navalkele said, “we do know that it’s likely highly transmissible. In comparison to the Delta variant, we don’t know how severe the disease can be, or if it will result in a surge in hospitalizations and deaths. Because there are so few cases, we will have to wait and see.”

Experts from the Centers for Disease Control and Prevention agree what we know so far about Omicron is limited, although some data is emerging about the possible effectiveness against Omicron of the two-dose Pfizer and Moderna or the single-dose Johnson & Johnson. But, the Omicron variant likely will spread more easily than the original SARS-CoV-2 virus, the CDC said this week on its website.

The CDC expects that anyone with Omicron infection can spread the virus to others, even if they are vaccinated or don’t have symptoms. There are cases of Omicron variant breakthrough infection reported worldwide, but most experts believe the current vaccines and boosters will offer about the same protection as they do for the  Delta variant in preventing severe illness, hospitalizations and death, the CDC says.

The best protection for Mississippians at this point? The vaccinations and booster, said Dr. Thomas Dobbs, Mississippi State Department of Health state health officer and UMMC associate professor of population health. All Americans ages 18 and above are eligible for a booster six months after they’re fully vaccinated, and children ages 5 and up can receive the two-dose Pfizer vaccine.

About 47 percent of Mississippi adults are vaccinated, the fourth-worst vaccination rate in the nation behind Idaho, the worst, Wyoming and Alabama.

“We were prepared for the appearance of this variant in Mississippi, and we need to remember that Delta is still a very active variant of COVID-19 currently in the state, as well,” Dobbs said Monday in a news release.

“Vaccines remain the best public health measure to protect people from COVID-19, slow the transmission rate, and reduce the likelihood of new variants emerging. COVID-19 vaccines are highly effective at preventing severe illness, hospitalizations, and death.”

Dr. Mary Taylor, Suzan B. Thames Chair and professor of pediatrics, said the advice given for adults also applies to children.

“We know how to limit the spread of COVID-19 and its variants,” she said. “Good hand hygiene including hand washing and using hand sanitizer, wearing face masks indoors and protecting children ages 5 and older with vaccination against COVID-19 are all steps we can take to protect our families against infection.”

Efficacy of the vaccines against infection from Omicron might drop from the 94-95 percent efficacy of Pfizer and Moderna immunizations, Navalkele said. “But, it should still remain effective in protecting against severe disease, hospitalizations and death based on knowledge from previous studies performed on other variants.”

It’s also unknown whether monoclonal antibodies will be effective in preventing severe disease and hospitalization from Omicron, Navalkele said, “but we encourage patients to take advantage of available treatment options. Our monoclonal antibody treatment recommendations will be the same as with the Delta variant. But, we will have to wait and see if that changes with Omicron.”

Children ages 5 to 11 can receive the Pfizer vaccine through the UMMC Children’s of Mississippi’s Batson Kids Clinic, 421 S. Stadium Circle near Veterans Memorial Stadium in Jackson. Make an appointment online at umc.edu/healthcare/make-an-appointment or call (601) 815-5300 or (888) 815-2005.

“We know that COVID-19 can easily spread from adults to children, and within households, it’s super- transmissible, so we need to encourage all who are eligible ages 5 and up to get vaccination as soon as possible,” said Dr. Charlotte Hobbs, professor of pediatric infectious diseases.

Vaccinations for Mississippians of all ages are available from health care providers, federally qualified health centers, independent and retail pharmacies, and county health departments. Schedule appointments at county health departments at covidvaccine.umc.edu, or call 866-498-4948 from 7 a.m. to 7 p.m., seven days a week.