Questions answered: COVID vaccines and diabetes

Dr Paula Diab addresses some of the more common questions and concerns around COVID vaccines in people with diabetes.

Who would have thought a year ago that we would be talking about COVID vaccines already? I graduated in the middle of the South African HIV epidemic (pre-antiretrovirals) and can remember at the time thinking that medication would take a lifetime to develop as HIV required completely new classes of medication. Within only five years of graduating, not only was medication available, but it had become available to all South Africans.

A year ago, I was again wondering how a vaccine could be developed as quickly as would be necessary and on such a large scale. But, the reality is that COVID vaccines are now available.

As a healthcare provider, I was fortunate enough to be one of the first people in South Africa to receive the vaccine and am now grateful that my patients will soon be offered the same.

Why are people with diabetes at risk of COVID?

It’s important to remember that you are not at risk of contracting COVID purely because you have diabetes. It seems that those with uncontrolled diabetes and other co-morbidities (hypertension, obesity, old age) may be at a higher risk than those with controlled diabetes and fewer complications from the disease.

We have also come to realise that diabetes care itself is affected by contracting COVID and therefore we need to try as much as possible to prevent the infection. This is why we are encouraging everyone with diabetes to get vaccinated as soon as possible.

Does getting the vaccine mean I can’t get the virus?

The main objective of the vaccines is to protect you against severe outcomes of COVID, but you may still be able to contract the virus and spread to others. Current evidence shows that you should still wear a mask and practice social distancing even after having the vaccine.

Which vaccine is best?

This question is a little like asking which the best car is to drive when you need to travel hundreds of kilometres and have only Shanks’ pony. Although all vaccines are produced in different countries and with slightly different technology, they are all showing good efficacy and safety. Worldwide, there are currently more than 60 vaccines in various stages of clinical trials.

Currently, there are no trials to show that one vaccine is superior to another or more effective for a particular population group.

Are the vaccines safe?

Although the speed at which the vaccines came to market was unprecedented, each vaccine has completed the standard three phases of clinical trials. These phases take a pharmaceutical product through a small group of people who are very closely monitored (phase 1), to larger groups, matched by ethnicity, age, comorbidities etc, (phase 2) and finally to much larger groups where it is compared to placebo (phase 3). At no stage was safety compromised with the COVID vaccines, only that the administrative process was expedited.

As an example, ethical approval for clinical trials usually takes months for committees to sit but with the COVID vaccines, most of these committees were called to emergency meetings and documentation provided that allowed them to decide within days so that the trial process could go ahead.

What are the side effects?

It’s important to remember that every medication and vaccination has side effects, but we need to rather weigh up the benefit and risk of the treatment being offered.

If you were offered a simple headache tablet that had the side effect of causing hair loss, it’s most likely that you wouldn’t take it. Headaches often tend to go away by themselves and the risk of hair loss would most probably outweigh the benefit of the medication. Yet, every day, people have chemotherapy that induces hair loss because this risk is outweighed by the benefit of placing a cancer into remission or greatly improving quality of life.

Initial side effects from the COVID vaccines are very similar to those of the general flu vaccines: pain at the injection site, general muscle aches, some nausea, and tiredness. These side effects generally indicate that an immune reaction is taking place (which is what you want).

International feedback is indicating that some, but not all, people with diabetes are experiencing slightly elevated blood glucose levels but these can be managed quite simply in conjunction with your diabetes care team.

What is an mRNA vaccine?

There has been a great deal of attention paid to the Pfizer/BioNTech and Moderna vaccines which are mRNA vaccines. This is the first vaccine to be produced with this technology. The truth is the technology had already been developed prior to 2020 but no suitable vector (virus) had been identified to test the vaccine. This was not technology that was developed de novo in 2020.

The usual mechanism of developing immunity is to give a small dose of the virus to which a person is allowed to develop their own immunity. This is the reason that some of the regular childhood vaccinations cause mild illnesses.

An mRNA vaccine uses a piece of the genetic material (the precursor to the illness) to create antibodies. It’s a little like giving the recipe for a cake so you can get out the required bowls, measuring jugs, ingredients etc and have a good idea how to make the cake but you don’t actually make it.

How should I monitor myself after having the vaccine?

It is generally recommended that you monitor your blood glucose levels for the first 24 to 48 hours after receiving the vaccine. Check your levels frequently, stay hydrated and keep in touch with your diabetes care team if you have any concerns. If you are prone to allergic reactions, make sure you have adequate emergency medication should you require it.

When should we expect to get vaccinated?

The optimistic response would be that hopefully by the time this article is printed, that South Africans over the age of 60 and with co-morbidities, such as diabetes, will be able to receive their vaccinations.

Certainly, the aim is that these groups of people should receive their vaccinations as part of phase 2 (May – October 2021) and that the rest of the population will be vaccinated from November 2021 onwards.

What happens if I refuse the vaccine?

Currently, it will not be mandatory for South Africans to be vaccinated. However, the quicker that we achieve herd immunity, the quicker life can return to “normal.” Even if you don’t receive the vaccine, you should still employ safety precautions.

What about children with diabetes?

Currently most vaccines are approved for people over the age of 16. Approving pharmaceuticals for children requires much stricter review and approval but various companies have requested clearance for ages 12-15. It is still thought that young children are at very low-risk of contracting severe COVID infection.

Hopefully, one day, we will be able to look back upon this time and be proud to have been part of this historic and unique event that changed the course of health care as we know it.

References available on request

Dr Paula Diab


Dr Paula Diab is a specialist family physician who enjoys the challenges that diabetes management has to offer. She runs a multi-disciplinary practice in Kloof, KZN, where she works with patients with diabetes and their families to allow them to gain control of their disease rather than being overwhelmed by the complexities and complications often associated with diabetes.