Moderna Vaccine higher blood sugar

I received the first dose of Moderna vaccine on February 6. Since then my blood sugar has been elevated slightly and I had to set a new profile on my Tandem pump (I am running Control IQ in sleep mode 24/7, manually blousing when over 140). I am still running 99-100% in range but my daily insulin usage has increased by approximately 5 units per day. Based on all the usual variables of daily management of diabetes, I believe I can only attribute this to the vaccine.

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I had the Moderna vaccination but only noticed a bit of tiredness and a sore arm. It doesn’t surprise me that it could affect glucose levels though. Hopefully yours will fall in a couple of days.

I get the second one on March 9th and I am worried about it, but I worry about everything.


I don’t know about you, but I notice an ebb and flow (slower, longer-term trends) to my total daily insulin use as well as slower trends relating to my blood glucose levels. I think it’s just part of the chaos that is diabetes.

I know you suspect that the vaccination has played some role, but don’t you think it’s possible that your vaccination could just be coincident with the variability of diabetes?

There could be a connection, of course, as we each can react differently to a vaccination.

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I got my first Moderna shot Jan 26; since then my blood sugar has been more elevated as well and higher spikes after meals; I am slowly increasing my insulin dose, having a hard time bringing it below 100. I am LADA and only on bolus with humalog therapy. Initially I thought it was related to my periods; but that’s past and my blood glucoses hasn’t improved. I attribute it to the vaccine… I am getting the second shot this weekend.

Wow I’m jealous. I’m in Canada (BC) and been told we won’t get any vaccine priority, so I’m expecting it by August(ish). Sorry it’s elevating your BS but great you have it!

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The reason for my suspicions is because I haven’t seen variability in my daily insulin since beginning Control IQ in January 2020. I was taking 20-25 units a day. Now I am taking 28-30.

I was not on a list to get my vaccine here in the U.S. I am 61 and Colorado has not began vaccinating high risk people, which would not help me since they require TWO high risk conditions to be on the next list of eligible recipients. My husband is over 70 and when I made his appointment (after weeks of jumping through hoops) the scheduler suggested I come with him. I did and because they had some no shows before us they said they would vaccinate me, too. I feel blessed that we are now on the same schedule of returning to the (new) world.


I was having higher spikes after meals, also. Today is the first day that I feel like I have my settings, along with increasing my pre-bolus time, close to covering the spikes. I am concerned for what may happen after the second shot. I hope it goes well for both of us.

That might change, Simon1. I expect it will change at the federal level in the US. Some states are already giving priority to t1s, but mostly just T2s

Fabulous news!!!

I’m 37 and T2, but very controlled (A1C from 12.2 to 5.8 and now 6 months med free, although 2 hrs of exercise a day to get there) so even if they change their minds on priority it may well not come to me anyway.

So glad you are on the same path as your husband!

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I have had both shots Of Moderna vaccine. I have not noticed any big changes in my blood sugar. I did not have any side effects from the shots. I must be weird.

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2 days ago Dr Richard K. Bernstein posted an urgent brief Youtube video warning that he had experienced serious LOWS following his vaccination.

It looks as if we need to be vigilant after being vaccinated, but as long as we take care, so much better to be vaccinated than not.

Just shared my experience to see what others experienced. As usual, everyone is different and our blood sugars are sometimes an enigma. Again, I am thankful to have the vaccine. Have not experienced lows at all. My average though is more like 110, pre-vaccine, and 115 since. It’s as if I have increased insulin resistance and will need to jump start my resistance.

I got first Moderna dose on 2/6 and did nice increase insulin needs for 24 hours. Then all seemed back to normal. I am thinking the 2nd one will have most of us down for day or so, and planning to increase basal insulin. Nice you have tandem doing much of the work for you.
How long did the higher insulin needs go on?

I had the Pfizer vaccine. Both doses. I only had a sore arm after the first. After the second I definitely had stronger side effects for 24 hours even to the point of increased pulse and BP along with a fever. I did have to increase my basal rate and correction boluses on my Tandem. Slowly decreasing my rates now after 2 weeks. Spoke to my endo last week at my visit and he says he has heard that and not surprised since it really revs up the immune system. Would do it all over again even with 2 weeks of side effects just to have the vaccine!


I’ve had both moderna shots. Did have to increase my insulin rates about 40% for a few days after first shot (Control IQ was asking if I wanted to bolus all the time), and am still up, 10 days after 2nd shot, but I also haven’t been outside because icy sidewalks, these past few days, so not the only variable. And I have always (since 1955) been quite labile diabetes-wise, and have on all recent pumps kept several basal profiles that I can change between as needed. Time in range went down 11% for a few days, was a hard one to get right, and now that I’ve got it back up I fully expect it to have to be adjusted again soon. Control IQ manages the small changes pretty well, but not this large – having to wake up and deal with it during 2 or 3 nights seemed such a nuisance last week, I’ve gotten so spoiled!

Things have improved the past couple of days. Ten more day until the second shot.

Did you take any medication close to the vaccine injection? I’m wondering if medication possibly interacted with the vaccine.

Just insulin.

I got the Pfizer vaccine this week. I had minor side-effects: a few chills, minor soreness at injection site, mild headache the morning after, some insulin resistance that is normal for immune response. (Side effects from the Shingrix vaccine were worse, like having the flu for a day) When I get the second dose I plan to take the next day off from work and use the “sick day” basal rate profile I programmed for Tandem. I use Control-IQ and Dexcom, my usual A1c is 5.3 and I am a Joslin medalist with 50+ years since T1D diagnosis.