August/September 2021 Issue

The COVID-19 Vaccine & Diabetes
By Densie Webb, PhD, RD
Today’s Dietitian
Vol. 23, No. 7, P. 28

Strategies for Counseling Patients Who Have Questions

As a dietitian, you won’t be asked to administer COVID-19 vaccines, but clients and patients probably will continue to ask you questions about their safety and efficacy. Safety is likely to be especially high on the list of questions for those with diabetes, so it’s best to be prepared with the most up-to-date information possible to help those with type 1 or type 2 diabetes, who may be vaccine hesitant or who want to be well informed before they get the jab.

What Is COVID-19?
First, it’s important to review the basics with patients. Remind them that according to the Centers for Disease Control and Prevention, COVID-19 is a disease caused by the novel coronavirus SARS-CoV-2. As of this writing, more than 600,000 Americans have died from the virus. And while most people with COVID-19 have mild symptoms and get better within weeks of illness, some experience post-COVID conditions that encompass a wide range of new, returning, or ongoing health problems. These conditions can linger for four weeks or more after first being infected with the virus. Older people and those who have underlying health conditions, including diabetes, are more likely to become severely ill and potentially die from COVID-19, making vaccination paramount for these populations.1

How the Vaccines Work
Another important discussion to have with patients involves explaining what vaccines are available and how the vaccines work. There are three safe and effective vaccines against COVID-19 that have been approved for emergency use by the FDA: the Pfizer-BioNTech, Moderna, and Janssen/Johnson & Johnson vaccines. An Emergency Use Authorization is a mechanism by which the FDA can make available medical preventive and treatment measures, including vaccines, during public health emergencies such as the COVID-19 pandemic.2

Some individuals express concern about the vaccines’ safety due to the speed of development, but this quick turnaround was due to the unprecedented sharing of research rather than cutting corners in the regulatory process. These vaccines are 95% effective at protecting against the virus. The Janssen/Johnson & Johnson vaccine is 85% effective at preventing severe disease.3 And none of these vaccines can cause a COVID-19 infection. The following is a description of how each type of vaccine prompts the body to recognize and protect itself against SARS-CoV-2:

• The Pfizer-BioNTech and Moderna vaccines are mRNA (messenger ribonucleic acid) vaccines. They contain material from the virus that causes COVID-19 that gives the body’s cells instructions for how to make a harmless protein. The protein is then copied within the cells. When the body recognizes the protein shouldn’t be there, production of T-lymphocytes and B-lymphocytes is triggered. These lymphocytes remember how to fight the virus that causes COVID-19 in someone who later comes into contact with the virus. The Pfizer-BioNTech vaccine is approved for individuals aged 12 and older; the Moderna vaccine is approved for those aged 18 and older.

• The Janssen/Johnson & Johnson vaccine contains a different virus, the adenovirus, which is modified to contain material from SARS-CoV-2. This is called a viral vector. Once the viral vector is inside the body’s cells, it instructs cells to make a protein unique to the virus that causes COVID-19 and replicates it. Like the mRNA vaccines, it prompts the body to build T-lymphocytes and B-lymphocytes that will remember how to fight that virus if someone is infected in the future. The vaccine is approved for use in people aged 18 and older.

• Though not yet approved in the United States, the Oxford-AstraZeneca vaccine also is a viral vector vaccine. It has been approved for different age groups in several other countries.4

The most common side effects of any of the COVID-19 vaccines are similar to those of other vaccines and include pain, redness, and swelling at the injection site, as well as tiredness, headache, muscle pain, chills, fever, and nausea.5

Importance of Vaccines for People With Diabetes
While there’s no evidence that people with diabetes are at greater risk of contracting COVID-19, there’s research to show that people with either type 1 or type 2 diabetes who are infected with the virus are three to four times more likely to develop severe illness or complications, and experience hospitalization, compared with people without diabetes.6 Dawn Noe, RDN, LD, CDCES, owner of Dawn Noe Nutrition and Consulting, based in Cleveland, says, “This is typically a fairly powerful statistic, and I find most people are receptive to the vaccine when learning about it.”

While it may seem counterintuitive, effective glycemic management (as indicated by glycated hemoglobin) before hospital admission for COVID-19 hasn’t been found to be associated with improved outcomes.7 That makes primary prevention by vaccination the only proven route for reducing the risk of severe illness, hospitalization, and death among people with diabetes. Several news articles broke in June about Texas resident Joshua Garza, a 43-year-old husband and father with diabetes, who had declined the opportunity to receive the vaccine in January. Shortly after, Garza contracted COVID-19, spent four months in the hospital due to severe upper respiratory illness, and underwent a double lung transplant that saved his life. To date, Garza deeply regrets not getting vaccinated when he had the chance but is now sharing his story nationally to urge others to do so.

A recent European study found that 1 in 5 hospitalized COVID-19 patients with diabetes dies within 28 days of admission. The researchers also found that patients who regularly took insulin—possibly indicating more advanced diabetes—had a 44% higher risk of death than those who didn’t take insulin. Long-term blood sugar management wasn’t associated with patient outcomes, but higher blood sugar at hospital admission was a strong predictor of death and of a lower chance of discharge.7 Overweight and obesity also have been associated with poor early prognosis in patients with diabetes younger than age 75 who have been hospitalized for COVID-19.8

Other conditions that put people with diabetes at even greater risk of severe illness from COVID-19 include CVD, kidney disease, and respiratory conditions.6

Vaccine Hesitancy
It’s likely that people with diabetes will ask about adverse effects following vaccination for COVID-19. Be prepared to answer. Side effects typically last a day or two and can be unpleasant, but usually they’re mild. Some people report only slight fatigue or no side effects at all.9

That said, it’s imperative that patients with diabetes monitor their blood sugar more closely than usual following vaccination, as it stimulates the immune system and thus can affect blood glucose levels. According to Lucille Hughes, DNP, MSN/Ed, CDCES, BC-ADM, FADCES, director of diabetes education at Mt. Sinai South Nassau in New York, people with diabetes should be aware that as the immune system is affected after vaccination, blood sugar may increase, so they may need to adjust their medication or insulin dose.

Amy Kimberlain, RDN, LDN, CDCES, a certified diabetes care and education specialist at Baptist Health South Florida in Miami and a spokesperson for the Academy of Nutrition and Dietetics, says, “People with diabetes are not able to process glucose as well during illness. Their overall immune response is weaker, and their circulation is impaired. The side effects of the vaccine mimic flulike symptoms and can impact blood sugar levels for that very reason.”

African Americans are particularly at risk of COVID-19 complications, as they’re more likely than white Americans to have conditions such as obesity and type 2 diabetes that are associated with increased risk of serious illness.10 While African Americans have a greater incidence of conditions that put them at higher risk than white Americans of severe complications from COVID-19, as a group they’re also more hesitant to be vaccinated against the virus. Current data show that nationally, African Americans are three times more likely than white Americans to contract COVID-19. Once exposed, African Americans are twice as likely to die from the virus, making vaccination a high priority for this population.11,12

However, the African American community reports higher rates of vaccine hesitancy than not only whites but also other ethnic and racial minorities.13 But African Americans also report higher levels of fear of COVID-19 infection than their white peers14; it’s important to let African American clients and patients with diabetes know that, when the vaccines were tested, 8% to 9% of participants had type 1, type 2, or gestational diabetes and almost 10% of the total trial participants were African American.

Addressing Concerns
According to Noe, it’s important to educate all people about the importance of getting vaccinated and help minimize their worries and fears about doing so without lecturing or becoming judgmental. She offers the following tips for discussing the COVID-19 vaccine with people with diabetes:

Frame your messages in terms of gain. “Getting the COVID-19 vaccine will protect you and your family.”
Offer novel information about the disease. “We’re learning that COVID- 19 infections can result in longer-lasting and debilitating health problems, such as ongoing fatigue and heart and lung problems.”
Appeal to altruism. “Getting the vaccine helps everyone get back to normal.”
Affirm values. “I know you care deeply about [the economy, taking good care of your health, protecting your mother] and getting the vaccine can help you do that.”

Noe also suggests dietitians check out these motivational interviewing techniques from The New York Times at

Kimberlain offers dietitians the following scripts to follow if they’re unsure how to broach the subject with clients and patients:

Be understanding. “Thank you for sharing your concerns about the vaccine. It’s understandable that you have questions and concerns about the vaccine.”
Ask permission to share information about the vaccines, such as, “The mRNA vaccines do not enter the nucleus of the cells, so they cannot cause genetic changes.”
Discuss side effects. “Side effects are usually mild. They can include fatigue and body aches that usually occur after the second dose and typically go away in a few days. It’s also common to have pain in your arm where you receive the vaccine.”
Talk about vaccine development. “The speed of development was due to the sharing of research. Every study and every phase of every trial was carefully reviewed and approved by a safety board and the FDA. The process was transparent and rigorous and the safety data will continue to be collected two years after each vaccine is first administered to ensure their safety.”
Explain the risk for people with diabetes. “It’s important for you to know that you are at a three to four times higher risk of severe illness and hospitalization because you have diabetes, and this is why the doctor highly recommends it.”
Express genuine concern for their health. “My concern for you is that you could get COVID-19 and that also could increase your chance of developing another autoimmune condition.”
Make a recommendation. “I strongly recommend that you consider getting the vaccine. I can provide a list of places administering the vaccine.”
Provide tips for prevention if they choose not to get the vaccine. “If you choose not to get the vaccine, it’s important that you continue to practice social distancing and mask wearing for now. I will make sure to let the doctor know about your concerns.”

In fact, in a survey conducted before the approval of the vaccine, respondents indicated a greater likelihood of accepting the COVID-19 vaccine if it was recommended by their clinician.15 Health care provider recommendations, including RDs counseling people with diabetes, are critical to promoting vaccine uptake among vaccine-eligible patients.16

Bottom Line
Kimberlain urges practitioners to uncover each person’s reason for not getting the vaccine. Based on her recent experience stationed at a vaccine site, she says it may be a life circumstance that has nothing to do with vaccine hesitancy or any antivaccine belief.

Noe agrees: “I always ask people with diabetes what is the most important or pressing topic they need to know.” As a nutrition consultant informed about the COVID-19 vaccine, it’s important to find a way to encourage people with diabetes to protect themselves against infection with COVID-19.

— Densie Webb, PhD, RD, is a freelance writer, editor, and industry consultant based in Austin, Texas.


1. Frequently asked questions. Centers for Disease Control and Prevention website. Updated May 25, 2021. Accessed May 31, 2021.

2. Emergency use authorization for vaccines explained. FDA website. Updated November 20, 2020. Accessed May 30, 2021.

3. Johnson & Johnson COVID-19 vaccine authorized by U.S. FDA for emergency use—first single-shot vaccine in fight against global pandemic. Johnson & Johnson website. Published February 27, 2021.

4. Understanding how COVID-19 vaccines work. Centers for Disease Control and Prevention website. Updated May 27, 29021. Accessed May 30, 2021.

5. Possible side effects after getting a COVID-19 vaccine. Centers for Disease Control and Prevention website. Updated May 25, 2021. Accessed May 30, 2021.

6. Gregory JM, Slaughter JC, Duffus SH, et al. COVID-19 severity is tripled in the diabetes community: a prospective analysis of the pandemic’s impact in type 1 and type diabetes. Diabetes Care. 2021;44(2):526-532.

7. Cariou B, Hadjadj S, Wargny M, et al. Phenotypic characteristics and prognosis of inpatients with COVID-19 and diabetes: the CORONADO study. Diabetolgia. 2020;63(8):1500-1515.

8. Smati S, Tramunt B, Wargny M, et al. Relationship between obesity and severe COVID-19 outcomes in patients with type 2 diabetes: results from the CORONADO study. Diabetes Obes Metab. 2021;23(2):391-403.

9. Pal R, Bhadada S, Misra A. COVID-19 vaccination in patients with diabetes mellitus: current concepts, uncertainties and challenges. Diabetes Metab Syndr. 2021;15(2):505-508.

10. Brancati FL, Kao WH, Folsom AR, Watson RL, Szklo M. Incident type 2 diabetes mellitus in African American and white adults: the Atherosclerosis Risk in Communities Study. JAMA. 2000;283(17):2253-2259.

11. Eligon J, Burch A, Searcey D, Oppel R. Black Americans face alarming rates of coronavirus infection in some states. The New York Times. April 7, 2020.

12. APM Research Lab Staff. The color of coronavirus: COVID-19 deaths by race and ethnicity in the U.S. APM Research Lab website. Updated March 5, 2021. Accessed May 29, 2021.

13. Malik A, McFadden S, Elharake J, Omer S. Determinants of COVID-19 vaccine acceptance in the US. EClinicalMedicine. 2020;26:100495.

14. Bunch L. A tale of two crises: addressing COVID-19 vaccine hesitancy as promoting racial justice. HEC Forum. 2021;33(1-2):143-154.

15. Finney Rutten LJ, Zhu X, Leppin AL, et al. Evidence-based strategies for clinical organizations to address COVID-19 vaccine hesitancy. Mayo Clin Proc. 2021;96(3):699-707.

16. Reiter PL, Pennell ML, Katz ML. Acceptability of a COVID-19 vaccine among adults in the United States: how many people would get vaccinated? Vaccine. 2020;38(42):6500-6507.