It’s less clear whether there is any risk for people who carry the sickle cell trait, but researchers think that the potential exists. It’s not known whether SCD increases a person’s risk of catching COVID, but those who do get the virus have a higher risk of hospitalization and pneumonia.

For people with SCD, the first symptom of COVID is often pain. Symptoms of COVID can also mimic symptoms of common SCD complications.

Learn more about the risk of COVID-19 with SCD, potential complications, how the pandemic may affect your SCD treatment, and what you can do to lower your risk.

Sickle Cell Disease vs. Sickle Cell Trait

Sickle cell disease is a hereditary condition that predominantly affects Black Americans in the United States, as well as forebears from Sub-Saharan Africa, the Americas (South America, Central America, and the Caribbean), and some Mediterranean countries.

SCD is usually diagnosed in infancy as part of routine newborn screening. However, a test called hemoglobin electrophoresis is needed to distinguish between SCD and sickle cell trait, as well as to look for different types of the disease (such as HbSC).

In the United States, SCD affects nearly one in 400 Black people. The trait is present in one out of 13 Black people in the country. Globally, the sickle cell trait is thought to affect around 300 million people. The disease is most common in Africa, where the rate is roughly 10 times higher than it is in the United States.

With SCD, a mutated gene codes for an abnormal protein in the hemoglobin molecule (abnormal β-globin chain). Hemoglobin is the component of blood cells that delivers oxygen to the body.

The abnormal hemoglobin gives the red blood cells a sickle-like shape. The cells are not only more fragile than normal red blood cells—resulting in their breakdown and consequent anemia—but they often get stuck and cause blockages as they pass through smaller blood vessels.

These blockages (which are like “mini heart attacks”) can occur in the chest, abdomen, or joints, and end up affecting nearly every region of the body. When they occur, the result is usually severe pain, referred to as a pain crisis (vaso-occlusive crisis), as well as lack of blood flow (ischemia) to the area of the body where the blockage occurs.

Blockages or pain crises can be triggered by many factors, including infections.

Complications such as strokes, acute chest syndrome, pulmonary hypertension, and chronic pain are associated with a reduced life expectancy, though treatments designed to reduce pain crises have improved survival and quality of life for SCD patients.

Sickle Cell Disease and COVID-19 Risk

COVID-19 risk in people with SCD includes both their risk of getting the infection and the risk of severe disease if they get sick. The risk of getting the infection can be broken down into the risk of exposure and the risk of susceptibility to the infection when exposure occurs.

SCD primarily affects Black people, who have also been disproportionately affected by COVID. When looking at the risk of COVID illness and complications in Black people in the United States, it can be difficult to separate the risks associated with race and those that come from SCD.

COVID-19 Risk in Black People

Data from the CDC shows that Black people are at a higher risk for infection, hospitalization, and death related to COVID illness than other racial groups.

Compared to non-Hispanic White people, non-Hispanic Black people are:

1. 1 times more likely to get COVID2. 8 times more likely to be hospitalized with COVID2 times more likely to die from COVID

Several reasons have been cited for the disparity. Overall, low-income groups and minorities have had worse outcomes associated with COVID-19.

There are differences related to risk factors. For example, diabetes and obesity are risk factors for severe COVID. The rate of diabetes among Black adults is 16.4% compared to 11.9% in White adults.

Obesity is also more common, with 38.4% of Black adults in the United States considered to be obese compared with 28.6% of White adults.

Sickle Cell Disease and Risk of Exposure to SARS-CoV-2

People who have SCD often require more frequent medical care than people who do not have the disease. The increased need for medical care translates to a higher likelihood of being exposed to people who are infected with SARS-CoV-2.

There have not been enough studies looking at how many people with SCD get COVID compared to the general population, but visits to the pharmacy for medication, hospitalizations for pain crises, and transfusions may increase their chances of exposure.

Sickle Cell Disease and Susceptibility to COVID-19

Whether a person with SCD is more likely to develop COVID-19 when exposed to SARS-CoV-2 is still uncertain, although the disease may affect immune function.

In addition, people with SCD often have reduced spleen function (functional hyposplenism), which can affect their body’s ability to fight bacterial infections (including secondary bacterial infections that can occur with COVID-19).

Sickle Cell Disease and Risk of Severe Outcomes With COVID-19

People with SCD are at higher risk for developing severe illness and are more likely to be hospitalized with COVID-19 and other viral infections than people without the condition.

For example, during the H1N1 influenza pandemic, children with SCD were more likely than children without SCD to develop acute chest syndrome, require intensive care (17% vs. 3%), or require mechanical ventilation (10% vs. 0%).

In another study looking at seasonal influenza, children with SCD were 56 times more likely to be hospitalized with the infection than children who did not have the disease.

Coexisting Risk Factors

In addition, common complications of SCD such as kidney disease and strokes may increase the risk of serious COVID outcomes.

One study looked specifically at additional risk factors for patients with SCD who were hospitalized with COVID-19 in the United Kingdom. Other medical conditions that have been associated with worse COVID outcomes included neurological impairments caused by a stroke, advanced kidney disease, and evidence of iron overload from transfusions (which usually affects the heart and liver).

Even among people who did not have coexisting conditions, many had recurrent hospitalizations for vaso-occlusive crises or pain crises (episodes in which blood flow is interrupted to areas such as the bones, joints, and other organs because of the abnormally shaped red blood cells).

Studies have now found that people with SCD might be more likely to have serious outcomes from COVID-19. In a large medical record study from January to September of 2020, Black people with SCD were more likely than Black people without SCD to:

Require hospitalization (roughly twice as likely)Develop pneumonia (2. 4 times more likely)Develop pain (3. 4 times more likely)

Despite the increased risk of complications and hospitalizations, the study did not indicate that people with SCD were more likely to die from COVID-19. The researchers hypothesized that perhaps Black people with SCD were more likely to seek medical care (due to their history of requiring frequent medical care) and receive early treatment than people who do not have the disease.

In a U.K. study looking at the relative risk of a number of pre-existing medical conditions with COVID-19, it was found that people with SCD had a significantly increased risk of hospitalization compared to the general population.

In an American registry study (Medical College of Wisconsin) looking at 178 people with SCD, 69% required hospitalization and 7% died. The average age of those who died was 38.5 years.

In a smaller study in the United States that included 66 people with SCD, 75% required hospitalization, and the mortality rate was 10.6%—despite the average age of the patients being 34 years and the average overall mortality rate in the United States being around 3%.

The most common presenting symptom in the study was also a pain crisis, and 60% of those hospitalized experienced acute chest syndrome. Risk factors for more severe disease with SCD included chronic kidney disease, older age, and a history of strokes.

Sickle Cell Trait and Risk of COVID-19

Sickle cell trait—carrying one abnormal gene that results in one abnormal globin chain in hemoglobin—is largely an asymptomatic disease (people usually do not have any symptoms).

However, stressors such as a low blood oxygen level (hypoxia), can lead to complications that are similar to (but typically milder than) those seen in people with SCD. One example is blood clots (thromboembolism).

Studies have found that the risk of blood clots in the lungs (pulmonary embolism) is two times higher in people who have sickle cell trait than in the general population. The trait is also linked to an increased risk of strokes (ischemic stroke) and kidney disease, as well as coronary artery disease in people who have kidney disease.

Since COVID-19 infections can lead to low oxygen levels, doctors are concerned that people with sickle cell trait might be at a greater risk of complications.

In the study looking at outcomes from COVID-19 among people with SCD, there were no significant differences in symptoms, hospitalizations, or mortality between Black people who carried the sickle trait and those who did not have the trait.

However, little research has addressed the concern specifically. People who have sickle cell trait still might be at an increased risk of unrecognized sickle cell complications. It’s important to let your doctor know if you carry the sickle trait if you are diagnosed with COVID-19.

Complications of Sickle Cell Disease and COVID-19

For people with sickle cell disease, the COVID-19 pandemic may present complications related both to access to care and as a result of contracting the infection itself. Recognizing the symptoms of COVID-19 may also pose a challenge for some people.

Recognizing the Symptoms of COVID-19

Recognizing COVID-19 in people with SCD can be challenging because the symptoms may overlap with those of complications of SCD. For example, symptoms such as shortness of breath, a cough, fever, or pain can be caused by COVID, as well as SCD complications like blood clots in the lungs (pulmonary emboli), acute chest syndrome, or heart failure (pulmonary hypertension).

The most common presenting symptom of COVID in people with SCD is varying degrees of pain. Since pain crises are common with SCD, the symptom might not be associated with COVID. The situation is further complicated because the symptoms of COVID can be variable even in people who did not have SCD.

Other symptoms of COVID, such as loss of sense of smell, a dry cough, and shortness of breath, might not help a doctor diagnose the virus in people with SCD. In one study, people with SCD did not report feeling short of breath despite having very low blood oxygen levels.

Complications of COVID-19 With Sickle Cell Disease

COVID complications might be more severe in people with SCD. People with SCD may also have COVID complications that are not usually seen in people without the disease.

The overlapping symptoms of COVID-19 and complications of SCD prompted the American Society of Hematology to develop a sickle cell disease emergency room checklist to help doctors tell the difference between the two conditions.

Acute Chest Syndrome

Acute chest syndrome is a potentially life-threatening complication of SCD. There is increasing evidence that COVID-19 pneumonia can cause the syndrome.

While all of these crises are painful and can cause damage, acute chest syndrome (lung injury) is especially dangerous. The mainstay of treatment is blood transfusions.

There is limited data available, but one study in Brazil found that three out of 38 pediatric patients admitted to the hospital with COVID-19 developed acute chest syndrome. The initial symptoms of COVID in these children were similar to those seen in adults and characterized by pain more often than typical COVID-19 symptoms. All of the children in the study did well after treatment with blood transfusions, antibiotics, and oxygen.

Acute chest syndrome has been noted in case reports of adults with SCD.

Pain Crisis (Vaso-Occlusive Crisis)

Pain is often the first sign of COVID-19 in people who have SCD. A pain crisis may affect many regions of the body, but is often seen in the bones and joints.

The treatment consists of blood transfusions and pain management. In the Brazilian pediatric study, the children who were on preventive hydroxyurea appeared to do better than those who were not on preventive therapy.

Pneumonia and Respiratory Failure

As with the general population, people with SCD who get COVID may develop pneumonia, which can lead to respiratory failure and the need for mechanical ventilation.

Blood Clots

People with SCD are at an elevated risk of blood clots, including pulmonary emboli that have been seen in people with severe COVID-19.

Cytokine Storm

An overreaction of the immune system that does more damage to the body than the infection itself (a “cytokine storm”) has been identified as a serious complication of COVID-19.

There have not yet been studies examining the incidence of cytokine storms in people with SCD relative to the general population, but SCD does cause a chronic inflammatory state that may potentially increase the risk.

There is no definitive research available on long-term symptoms (long COVID) related to COVID-19 infections in people with SCD. What is known is that COVID-19 can affect the kidneys, sometimes severely. Kidney disease is already common with SCD.

Reports of chronic lung damage and heart damage in COVID survivors who do not have SCD also raise concerns, as this could compound the heart and lung complications that are common in people with SCD. It could also make the diagnosis of acute chest syndrome more challenging.

Sickle Cell Disease Treatments and COVID-19

If you need to get SCD treatment during the COVID-19 pandemic, it’s important to look at both how your treatments may change related to pandemic restrictions, as well as how your treatment might be different if you get COVID.

Treatments During the COVID-19 Pandemic

If you take medications such as Oxbryta (voxelotor) and Adakveo (crizanlizumab), you might not be able to receive these treatments if you are exposed to or get COVID. Most other SCD treatments are OK to continue if you are exposed to or get the virus.

Hydroxyurea

Hydroxyurea is one of the primary treatments for SCD. The medication may reduce the need for blood transfusions at a time when there is a shortage of donated blood. What’s more, even when blood donations are available, going to the clinic for a blood transfusion carries the risk of potential exposure to COVID.

Pain Control

Pain is common with SCD. In some cases, people who would ordinarily be hospitalized for treatment with intravenous (IV) pain medications might be treated with oral medications to avoid going to the hospital and risking exposure to the virus.

Stroke Prevention

Transfusions or exchange transfusions to prevent strokes, acute chest syndrome, or painful erections (priapism) should be continued during the pandemic. The exception would be if the pandemic has caused shortages that make the treatment unavailable.

Children who have a history of strokes have a particularly high risk of recurrent strokes caused by low hemoglobin levels. Some researchers suggest beginning hydroxyurea therapy (for those not already receiving the medication) if there is a chance of a blood shortage. Hydroxyurea may also reduce the risk of pain crises and acute chest syndrome.

For those who are not being treated with Oxbryta, therapy might be considered for those who have low hemoglobin levels and who have difficulty with transfusions because they have antibodies against some antigens in blood products.

Treatment for Spleen Dysfunction or Absent Spleen

For people with SCD who have reduced function of their spleen, staying up to date on immunizations, particularly the pneumonia vaccine, is important. Some people with SCD also take antibiotics.

Transplant Candidates/Recipients

The only “cure” for SCD is a bone marrow transplant. However, the immunosuppression that is needed to address the strong chemotherapy required prior to a transplant and the post-transplant immunosuppression could be challenging in areas with high rates of COVID transmission.

While many medical institutions have resumed transplantations and gene therapy for SCD, this may change if COVID cases rise again.

Prevention of Vaso-Occlusive Crises

Preventing pain crises is essential for improving the quality of life for people with SCD. It’s also a particularly important way to reduce the need for hospitalization during the pandemic.

Medications that are approved by the Food and Drug Administration for decreasing the frequency of pain crises include hydroxyurea, L-glutamine, Oxbryta, and Adakveo.

Treatments in People Who Develop COVID-19

People with SCD who contract COVID-19 should be closely followed by their treatment team, even if their symptoms are mild. Doctors may consider hospitalizing SCD patients with COVID sooner than they would people who do not have the disease.

Oxygen Monitoring

Oxygen therapy is used for people with low oxygen levels (hypoxia) who have COVID whether they have SCD or not.

However, for people with SCD, continuous monitoring (oximetry) might also be considered if they have experienced significant hypoxia without feeling short of breath in the past.

Management of Anemia

COVID-19 is associated with reduced hemoglobin levels, and people with SCD already have low levels of hemoglobin.

Low levels of hemoglobin can be treated with blood transfusions. If severe, red blood cell exchange transfusion might be needed.

Pain Control

A significant number of people with SCD develop pain (a pain crisis) when they get COVID, and they might require IV pain medication.

Antiviral Medication

People with SCD who test positive for COVID-19 are candidates to receive Paxlovid, an antiviral medication that can help prevent progression to severe disease. Paxlovid should be started as soon as possible after symptoms develop, or at least within the first five days.

How to Stay Safe

Staying safe with SCD during the pandemic involves many of the same measures recommended for the general population. There are also some extra precautions that you might consider:

Wear a mask when in public indoors: Even if you are fully vaccinated, if you live in a place with a high rate of COVID transmission, wearing a face mask may help reduce your risk. While infections in people who are immunized (breakthrough infections) are uncommon, they do occur. It is unknown at this time what the risk of breakthrough COVID infections is for people with SCD specifically. Practice social distancing: If you are around people who are unvaccinated, or in a setting in which you do not know the vaccination status of others, staying six feet apart from others can help reduce your risk. You should also avoid coming into contact with people who you know have been exposed to COVID or who are currently sick. Avoid crowds: Even if your risk of COVID-19 is low, your susceptibility to other infections is increased with SCD. Wash your hands frequently: Do this for at least 20 seconds, or use hand sanitizer if soap and water are unavailable. Get vaccinated and boosted: If you are not sure which vaccine is the best option for you, talk to your doctor.

Other safety measures you can take that are specific to SCD include:

Stock up on any medications you take: This may not be possible if you are prescribed pain medications. Talk to your doctor about your medication needs to ensure that you can get them refilled. Talk with family and friends about your increased risk: Encourage them to get vaccinated to help you stay healthy.

A Word From Verywell

People who have chronic medical conditions, including sickle cell disease, might be more likely to get seriously ill or even die if they get COVID-19. While there are vaccines available that can greatly reduce the risk of severe COVID illness, people with SCD might be worried about the potential for blood clots or a pain crisis triggered by the shots.

It’s important to discuss your SCD treatment, as well as the preventive measures that you should take during the pandemic, with your doctor. While the benefits of vaccination likely outweigh the risks, your unique medical situation will need to be considered.

As for people who do not have SCD, if you live in an area with a high rate of transmission, you might need to continue to take precautions like wearing a face mask and social distancing even if you get vaccinated. Other measures, like frequently washing your hands and avoiding crowds, can also reduce your risk.

If you are concerned about your risk of being exposed to COVID when you are going to and from treatments, let your doctor know. You might be able to do some appointments through telehealth.

Which people with sickle cell disease are most at risk from COVID-19?

Statistics regarding the risk of hospitalization and poor outcomes with COVID-19 look at averages among people with SCD, but your risk may vary depending on factors such as your age, coexisting conditions, and how the infection is treated.

In one study, a group of 66 people with SCD were followed from the time that they were hospitalized with COVID-19 until three months after they were discharged. Altogether, 75% required hospitalization and 10% died, though the severity of the infection varied significantly among the participants.

As noted in other studies, the most common initial symptom of COVID in people with SCD was pain (vaso-occlusive pain). Acute chest syndrome occurred in 60% of the people who were hospitalized.

People who had chronic kidney disease before they contracted COVID were more likely to be hospitalized, and death was more common in those who were older and had a history of congestive heart failure, pulmonary hypertension, strokes, or chronic kidney disease regardless of the subtype (genotype) of SCD.

The people who died from COVID were less likely to have received blood thinners (anticoagulation) while they were in the hospital. None of the people who died had been treated with hydroxyurea or other sickle cell disease-modifying therapies such as L-glutamine, Oxbryta, or Adakveo.

Is it safe to get the COVID vaccine if you have sickle cell disease or the trait?

The benefits of getting vaccinated against COVID-19 outweigh the risks for most people, including people who have SCD. If you have questions about getting vaccinated—including whether you need a “booster” shot—talk to your doctor about your options.

Is the COVID-19 vaccine effective in people with sickle cell disease?

Early studies have found that some people with underlying medical conditions are less likely to develop antibodies to the infection after they receive a COVID vaccine, though whether this is the case for people with SCD is not yet known.

Based on how people with SCD typically respond to other vaccines, such as the flu shot, it’s thought that people with SCD will respond to the COVID vaccines but might develop lower levels of antibodies than people who do not have the condition. There is also a chance that the protection afforded by the vaccine will not last as long for people with SCD.

Which COVID-19 vaccine is best for people with sickle cell disease?

The benefits of any vaccine outweigh the risks from COVID-19 for people with SCD. However, if you are concerned about your risk of blood clots, you may want to discuss the vaccine options with your doctor.

Could the COVID-19 vaccine cause a pain crisis?

Some people with SCD have expressed concerns that the COVID vaccine will trigger a pain crisis.

While it’s unknown whether the risk of pain crisis is higher after receiving the COVID vaccine, it is known that the risk of a pain crisis in people who get COVID is significant.

The benefits of the vaccine will almost always outweigh the potential risks. If you feel anxious or remain hesitant about being immunized, talk to your doctor.

The information in this article is current as of the date listed. As new research becomes available, we’ll update this article. For the latest on COVID-19, visit our coronavirus news page.