Question:

I tested negative two days after finishing my five days of Paxlovid. However, I tested positive three days later. Is this an apparent COVID-19 rebound situation? Should I request another five-day dose of Paxlovid? 

Answer from infectious diseases expert James Lawler, MD:

Effectiveness of Paxlovid

Paxlovid is an oral medication proven to reduce the severity of COVID-19. The at-home treatment received emergency use authorization, or EUA, from the Food and Drug Administration. 

To qualify for a prescription under the EUA, you must:

• Be 12 years or older and weigh at least 88 pounds
• Be at high risk for severe disease
• Have had a positive COVID-19 test result

Studies show Paxlovid is nearly 90% effective in preventing hospitalization and death in patients who use it early. Ideally, that's within the first five days of symptoms. 

It's considered far more effective than other COVID-19 treatments like molnupiravir. Molnupiravir only reduces the rate of hospitalization and death from COVID-19 by 30%. Paxlovid is also more convenient than remdesivir. Remdesivir is an injection administered by a doctor or nurse in a hospital or clinic.

Paxlovid "rebound"

The media often talks about Paxlovid "rebound" cases or re-emergence of symptoms within days of completing treatment. But studies show people who are not treated with Paxlovid experience rebound at similar rates. So, it is unclear whether Paxlovid makes rebound cases more frequent. Regardless, symptoms during rebound are usually milder compared to the initial illness. 

Currently, studies are exploring if additional days of Paxlovid can reduce the rebound rate. In the meantime, the current FDA EUA only allows for five consecutive days of treatment. 

If you experience rebound symptoms, you are likely contagious again. You should isolate yourself to prevent passing the disease to others. For more information, consult your doctor or the CDC guidelines.