CDC Director: ‘As the Virus Changes, the Science Changes’

For the first time in a year, CDC Director Rochelle Walensky, MD, held a CDC-only media briefing on Friday to discuss quarantine guidance, the state of the pandemic for children, and the possibility of a second booster shot.

She said that while she did over 80 briefings last year, “we heard over the last week that there was interest in hearing from the CDC independently,” and said that she anticipated this would be the first of many briefings.

“I am committed to continue to improve as we learn more about the science,” Walensky said. “The virus is … constantly throwing us curve-balls. As the virus changes, the science changes.”

Top of mind for most reporters was CDC’s controversial shortened quarantine guidance from 10 days to 5 days. Walensky reiterated that the guidance applies only to those who “do not have symptoms anymore” and that wearing a “well-fitting mask” from days 6-10 since infection was detected is essential.

“The guidance is very clear that you should not leave isolation if you’re still symptomatic,” she added. “The first indication is do your symptoms remain or not.”

Even if a patient leaves isolation, Walensky still recommended that people “don’t go to restaurants, avoid traveling” and avoid contact with immunocompromised people.

“Wear a mask and anticipate you might have residual contagion still within you,” she said.

When asked why testing was not included as a prerequisite to discontinue isolation, Henry Walke, MD, of the CDC, said that rapid antigen tests are best used early in the course of illness, but “aren’t authorized by the FDA to evaluate the duration of infectiousness.”

“The significance of an antigen test late in the course of illness” is unclear, he said, and a negative test “doesn’t necessarily mean the absence of virus.”

The Kids Aren’t Alright

Walensky also addressed how the current Omicron wave has affected children, noting that “pediatric hospitalizations are at the highest rate compared to any prior point in the pandemic.”

Hospitalizations are also increasing among children ages 0-4 who are too young to get vaccinated, she added, and stressed the importance of surrounding these kids with people who are vaccinated to provide them protection.

“We are still learning about the Omicron variant in children and whether increases [in hospitalization] reflect a greater burden of disease in the community” or a lack of vaccination, she said.

Walensky lamented that only 16% of children ages 5-11 are fully vaccinated, and that children older than age 4 are more likely to be hospitalized if they are unvaccinated. In fact, she pointed out that unvaccinated adolescents ages 12-17 are 11 times more likely to be hospitalized than those who are fully vaccinated.

She said she endorsed a recommendation for a booster dose at least 5 months after the primary series for adolescents ages 12-17 “to ensure they are up-to-date with vaccines and protected against the Omicron variant.”

Whither a Fourth Dose?

Along those lines, Walensky added that she endorsed FDA’s amended emergency use authorization (EUA) for a booster dose of Moderna’s COVID vaccine for adults at least 5 months after the primary series (it was previously 6 months).

Reporters also asked about Israel’s recent recommendation for a fourth dose, and wondered if the U.S. would be following suit. Walensky noted that only 35% of the population eligible for booster doses, or 73 million people, have received them.

The priority “has to be to maximize protection for tens of millions of people who continue to be eligible for a third shot before thinking about what a fourth shot would look like,” she said.

However, she added that she is in touch with colleagues in Israel, and will be keeping an eye on how boosters are working, and their potential waning effectiveness not just against infection, but severe disease.