A clinical trial for pregnant women who have recently been diagnosed with COVID-19.

The oral treatment PAXLOVID™ (nirmatrelvir/ritonavir) received US FDA approval on May 25, 2023, for the treatment of adult patients with mild-to-moderate COVID-19 who are at high risk for progression to severe COVID-19, including hospitalization and death. 

Doctors & scientists are continuing to study nirmatrelvir/ritonavir to determine whether it is safe and effective for pregnant women who have been diagnosed with COVID-19. 

Pregnant women are at a higher risk of progressing to severe COVID-19. If you are pregnant, and have COVID-19, you may consider joining this clinical trial. Women who chose to participate will receive PAXLOVID™ and all study-related medical procedures at no cost and will get care from a dedicated team of healthcare professionals for the duration of the trial. Please note that no placebo is used within this study.

For more information, please consult the “About Study Medicine” page.

Who may participate

Joining a clinical trial is an important and personal decision. Your doctor may have mentioned this study to you, or perhaps you found your way here by yourself. Either way, thank you for your interest.

This study may be an option for women who: 

  • are in their 2nd or 3nd trimester of pregnancy 
  • tested positive for COVID-19 within the last 5 days
  • have had COVID-19 symptoms for no more than 5 days 
  • currently have at least 1 symptom related to COVID-19 
  • have not been hospitalized for treatment of COVID-19 

There are other requirements for taking part in this study. The study doctor will explain these to you. 

Many factors, including genetics, race, ethnicity, and sex, can impact how people respond to a medicine. That is why it is so important that clinical trials include people of all backgrounds. The greater the diversity among clinical trial participants, the more we can learn about potential medicines, including how they work for different people.




18-50 years



Each clinical study has its own guidelines for who can participate, called eligibility criteria.  However, only the research study staff can determine if you qualify to enroll in the study.

What to expect

If you are interested in participating, the study team will schedule a visit to determine if this study is a good fit for you. 

If you are eligible and decide to participate, you will take PAXLOVID™ twice a day for 5 days.

You will be enrolled in the study until you deliver your baby or for 34 days (whichever is longer). You will attend at least 8 scheduled appointments. 

You may be reimbursed for study-related expenses.

Length of study treatment

5 days

Number of study visits

Up to 8 visits

Length of follow up

For 34 days or until delivery (whichever is longer)

Click on the video below to learn more about this trial

Frequently asked questions

What is mild to moderate COVID-19?
  • Mild-to-moderate COVID-19 has symptoms (such as fever, cough, sore throat, and more) that generally can be treated at home
  • These symptoms usually occur within the first few days of illness
  • Many people recover without needing special treatment, but in some people, COVID-19 becomes severe, often days into their symptoms. This is more likely if you have a high-risk factor.
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What can happen with severe COVID-19?

Severe COVID-19 is when a person gets very ill with COVID-19 and needs medical intervention. It can result in: 

  • Hospitalization
  • Needing a ventilator to receive adequate oxygen
  • Death 

Even if your symptoms are mild now, they can get worse quickly. Your symptoms are more likely to progress if you have certain risk factors.

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Do I need to be pregnant to participate in this study?

Currently, we are only enrolling pregnant women.

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Am I guaranteed to receive the study medicine?

Yes, all participants enrolled in this study will receive the study medicine PAXLOVIDTM (nirmatrelvir plus ritonavir). This study does not include a placebo (medicine with no active ingredient).

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What are the possible side effects?

All medicines have the potential to cause side effects. The study doctor will discuss the possible risks and benefits of participating in this study with you before you choose to enroll. You can choose to leave the study at any time.

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What if this study is not right for me?

You can choose to leave the study at any time, for any reason, including after you have discussed it with the study doctor. Choosing to leave the study will not affect your prenatal or future medical care.

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Does it cost anything to participate?

The study medicine and all study-related medical procedures are provided at no cost. You don’t need health insurance to join a clinical study. However, you (or your health insurance provider) may be responsible for medical expenses that are part of your usual healthcare. Talk with your study team or review the informed consent document to find out exactly what is covered.

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