AUGUSTA, Maine — The U.S. Centers for Disease Control and Prevention issued a notice Tuesday about a phenomenon called "COVID-19 Rebound" that leads to symptoms of the virus even after taking the treatment Paxlovid.
Paxlovid is an oral antiviral treatment created by Pfizer. Patients who are eligible take the pill for five days. To be eligible for the treatment, a person must:
- Test positive for COVID-19.
- Have symptoms.
- Be high-risk (age 40 or older; any age with an underlying medical condition, including being obese, overweight, or a smoker).
Patients must get a prescription for Paxlovid.
"That's scary for a lot of people, and it's understandably scary," Dr. Isaac Benowitz, a Maine CDC state epidemiologist, said. "COVID can lead to some pretty bad outcomes. But the tricky part is that COVID symptoms that return after you take Paxlovid are not as much as a cause for worry."
Both the Maine and U.S. CDC say "rebound" patients do not need more treatment, and experiencing rebound does not mean the treatment has failed.
"If you are at high-risk, you have a decent chance of landing in the hospital or having a really severe case," Dr. Benowitz said. "If you get Paxlovid, that risk almost completely goes away."
There is limited information about the safety and effectiveness of using Paxlovid to treat people with mild-to-moderate COVID-19 symptoms, according to Pfizer. Benowitz said the pill is about 85 to 90 percent effective at preventing severe COVID-19 symptoms.
"Limited information currently available from case reports suggests that persons treated with Paxlovid who experience COVID-19 rebound have had mild illness; there are no reports of severe disease," the U.S. CDC notice says.
There are still some unknowns about "rebound" cases; it is unclear whether the likelihood of transmission during rebound differs from the likelihood of transmission during the initial infection.
Benowitz assured the public that Maine has a healthy supply of Paxlovid coming into the state.
"That is the drug of choice and it's the most effective option for patients who can get it," Benowitz said. "If you're at risk for severe disease, you should get treated, even if your symptoms are really mild."
The data from Pfizer and the U.S. CDC find the pill is at least 85 percent effective in preventing severe disease.
The Maine CDC stresses that treatment is not a substitute for vaccination, which it said is the surest way to protect against hospitalization or death from COVID-19.
There is no data to show if people who are vaccinated have better outcomes with Paxlovid than those who are not.