COVID Vaccine Side Effects for Those w/ Previous Case of COVID

May 12, 2021 2:31 PM

I was a bit bowled over by how severe my reaction to Moderna vaccine was (much worse than actual COVID, which I had a mild case of a year ago). I felt poisoned. Just looking for any feedback on typical reactions to second shot for others who also went into the vaccine having had COVID prior.

...one thing that makes me uneasy is the lack of any change in dosing based on weight and health history. As a 150 pound male with a healthy immune system, perhaps a full dose just didn't make sense for my body (just speculating here, keeping in mind possible options for what to do about second dose.)

posted by Jon44 to Health & Fitness (11 answers total)

I haven’t had my second shot yet, but the first one (Moderna) really messed me up. I had asymptomatic covid around Christmas, so mild that I didn’t miss any work. Cant say the same for my reaction to the vaccine. I got it on Thursday at lunchtime, and by Friday afternoon I couldn’t work. My head was throbbing, my vision was blurry, I felt nauseated, and I was just all around tired. And of course, I could barely lift my arm high enough to put deodorant on. So yeah, your experience tracks with mine.

If it makes you feel better (pun intended), my symptoms were much more mild on Sunday and almost nonexistent on Sunday.
posted by kevinbelt at 3:09 PM on May 12, 2021 [2 favorites]

Medications are dosed based on body weight because the active ingredients are meant to be dispersed to the tissues. Vaccines work differently. The vaccine goes to the immune system, which is not scaled according to body weight.
posted by dum spiro spero at 3:21 PM on May 12, 2021 [14 favorites]

Folks who had Covid are generally having stronger side effects. From the NY Times:

Q: Are the side effects worse if you’ve already had Covid-19?
Research and anecdotal reports suggest that people with a previously diagnosed Covid-19 infection may have a stronger reaction and more side effects after their first dose of vaccine compared to those who were never infected with the virus. A strong reaction to your first dose of vaccine also might be a sign that you were previously infected, even if you weren’t aware of it.

If you previously tested positive for Covid-19 or had a positive antibody blood test, be prepared for a stronger reaction to your first dose, and consider scheduling a few days off work just in case. Not only will it be more comfortable to stay home and recover in bed, the vaccine side effects can resemble the symptoms of Covid-19, and your co-workers won’t want to be near you anyway.

And here's the research article that supports these findings.
posted by bluedaisy at 3:21 PM on May 12, 2021 [7 favorites]

Totally anecdotal, but my grandmother said her reaction to the first vaccine dose was much worse than her experience having COVID. It’s a thing.
posted by mekily at 3:50 PM on May 12, 2021 [1 favorite]

I'm a nurse who has vaccinated several thousand people at a neighborhood site, and have vaccinated many of these with both doses - all Pfizer.

People who have had past Covid infections have almost all noted a much more pronounced side-effects profile than people who have not had Covid after shot #1. This seems to be true whether Covid was severe or largely asymptomatic. Other people told me that they had more severe fever/chills than seemed typical after the first dose, but it's possible they had a prior undiagnosed infection. Without testing there's no way to prove this, but it's my working theory. Sore arm and headaches seem to be common, no matter past Covid infection or not in my anecdotal experience.

Good news for you - your second shot should be much less of a problem. While others will have a tougher time with #2, your more severe reaction will be behind you.
posted by citygirl at 4:03 PM on May 12, 2021 [11 favorites]

I was sick in March 2020 and had a clinical diagnosis of Covid-19. I tested negative at the time, but tests weren't yet seen as reliable; I tested negative for antibodies in September, but that's also not really an indicator that I didn't have it in March. Because of the negative tests I've never been 100% certain that I had it, but based on timing, exposure at work, and symptoms, it sure seems likely that I did even with the negative results.

I had the Moderna shot in March and April of this year. After the first shot (coincidentally a year and a day after my negative test in 2020) I was useless for about 36 hours. I had a nasty headache for most of the 36 hours, and had brain fog and fatigue. My wife didn't believe how bad the brain fog was until she tried to get me to decide on dinner and I couldn't remember the first thing she said. "Oh. You were serious." I never got a fever while I was awake, but my wife said in the middle of the first night I cocooned myself in all the covers on the bed. By the second morning I felt fine and went for my usual workout. After the second shot I had a mild headache for about four hours. That was it.

Does the fact my first shot was worse than my second confirm my original diagnosis from a year ago? WHO KNOWS.
posted by fedward at 6:06 PM on May 12, 2021 [3 favorites]

Response by poster: "Does the fact my first shot was worse than my second confirm my original diagnosis from a year ago? WHO KNOWS."
My situation was closest to yours. I never got tested when I thought I might have had COVID, but was exposed to someone who came down with a very severe case a few days after I was in her house.
My "first shot" symptoms seemed to confirm it was COVID as I felt similar "shards of glass" in my sinuses feeling (but with added fun of extreme nausea).
Thanks everyone for feedback--I didn't want to say it directly, but I was thinking of skipping the second dose (figuring doing my civic duty wasn't worth 2 days of agony), but sounds like there's a good chance it will be much milder and that the symptoms aren't necessarily a sign that this isn't healthy.
posted by Jon44 at 7:26 PM on May 12, 2021

For whatever anecdotal reporting is worth, my reaction to the first dose was much worse than to the second. I never had any symptoms or diagnosis, so "WHO KNOWS" is exactly right. But there's no reason to dread or skip that second dose based on feeling crappy after the first.
posted by Dip Flash at 7:39 PM on May 12, 2021 [1 favorite]

Best answer: I'm so glad you're planning to get the 2nd dose! The Moderna and Pfizer vaccines are effective against the variants (and variants are mostly what is circulating now), while the antibodies you might have after being infected (if you were) may not be so effective. We're not sure how long the "natural" antibodies after infection last, and also don't know if they are effective against variants. With both shots you're all set.
posted by citygirl at 8:17 PM on May 12, 2021 [2 favorites]

Hi, I'm an epidemiologist and toxicologist who develops vaccines. I also spend about half of the week examining tissues and serum and other things from people who've had the virus, with or without vaccination. I also had the virus last year before we were calling it Covid, and I've had both doses of the Moderna vaccine.

I'd like to say, as bluntly as I can, that despite the signs and symptoms you experienced with your first dose of vaccine, in no way was it worse than what the virus (perhaps silently) did to your body. Nevertheless, you're pointing out a conundrum in public health: when presented the option between an effective treatment that causes discomfort but no hazard, against an illness that can cause minimal discomfort but major, outwardly inapparent hazard, people will struggle to make a decision about receiving that treatment.

Dosing isn't as bizarre as it sounds. Ideally, most vaccines on the market would be formulated with higher (sometimes much higher) amounts of the antigens that are accepted in contemporary products. Do you know why that is? It's not because there's some concern about the safety or effectiveness of using more antigenic content, it's because of the issue raised above. More active ingredient means more immune response means more discomfort means word of mouth spreads that you'll feel bad means people don't take up the vaccine.

Yes, your second dose will possibly make you feel worse than your first dose did, which made you feel worse than the virus did. That all makes sense to me, given that it's a series of near-identical immune challenges. Nevertheless, the discomfort you'll feel is a syndrome of immune reactivity and not the production of trillions of copies of highly infective virus. I understand your wariness about voluntarily feeling gross, but any action undertaken to reduce the likelihood of the latter option is a civic good.

Hang in there.
posted by late afternoon dreaming hotel at 2:03 AM on May 13, 2021 [20 favorites]

I got COVID-19 the first week of January, 2021. I experienced chills and fever for one night, body aches, and severe fatigue for about a week straight.

My first COVID vaccine (Pfizer) was in late March, and it made my arm sore, but no additional side effects. My second vaccine was in early April. My arm was less sore the 2nd time, but about 36 hours after the shot, I got very tired, and slept for about 12 hours straight. After that, there were no lingering side effects at all.

All that being said, the combined effects of the vaccines (unlike your experience) doesn't hold a candle to those of my initial infection. But despite all the negative effects combined, nothing feels better than knowing that I'm now fully vaccinated, and that will help my friends and family and community stay healthy.
posted by xiix at 11:42 AM on May 13, 2021