What does only being able to get a single dose of a COVID vaccine mean?

April 2, 2021 9:08 AM

I had a mild allergic reaction (hives) to my first Pfizer COVID vaccine 15 minutes after the injection. The CDC says I shouldn't get the second dose, and my doctor agrees. What does that mean for me?

Studies show a single dose of the Pfizer vaccine is 80% effective compared to the 90% of getting both doses, so I feel relatively well protected.

But if I'm required to show I'm fully vaccinated, I can't. Any thoughts on how this will affect things in the future?

(And I fully agree I shouldn't get the second Pfizer shot - years ago I came down with hives after getting injected with x-ray contrast dye. The second time I went into anaphylaxis.)

(As for alternative vaccines, my doctor said, "I don't know yet if you would be a candidate for a different kind of covid vaccination at some point down the line but I suspect this hasn't been studied yet and we will have to wait and see." If I do get a second vaccine, I expect getting the Johnson & Johnson vaccine will likely be a safer choice than the Moderna.)

posted by Sock, Sock, Sock, Sock, Sock, Goose! to Health & Fitness (11 answers total)

I would expect that at least for some purposes you’ll be required to provide proof of vaccination or a valid medical excuse as to why you’re not vaccinated. For such situations, a note from your doctor saying “so-and-so had an allergic reaction to the vaccine” would presumably be acceptable.
posted by Johnny Assay at 9:13 AM on April 2, 2021 [8 favorites]

I don't think we know the answer to this, as governments are still focused on getting shots into arms, and most businesses are happy to take money from any masked customer. I'd imagine that any policy (gov or corporate) would have to take people like you in mind. Just like people with metal in their body get a doctor's note to go through airport security, I imagine you'd be able to do something similar. 80% effective is still great for a vaccine.
posted by coffeecat at 9:13 AM on April 2, 2021 [2 favorites]

There are (and will be) medical exemptions to vaccination requirements. I'm an epidemiologist and everyone in the field is working on this in one way or another, policy-wise. I would encourage you to ensure that your reaction is reported by your physician to VAERS and request some documentation to retain that attests to this step having been taken. Your physician (of the office of whomever administered your first dose) also has the contact information for the Pfizer-specific adverse events reporting group. I would ask for documentation that they had been contacted, too, as you may be recruited into a clinical study on allergy and protection (in which case Pfizer will probably pay for some or all of your follow-up steps if you choose to participate).

In the future, you may expect to be asked to consent to more monitoring should you receive a dose of a non-mRNA vaccine (i.e. getting the vaccine in a clinically monitored setting rather than at a mass vaccination site where you're asked to self-monitor for 15 minutes afterward). We already have routines like this in place for people who have grave tendencies toward anaphylaxis but who nevertheless need specific vaccinations. It may be as simple as going to an allergy/asthma clinic, taking antihistamines in advance of your injection, and so on.

In the meantime, I wouldn't worry about rushing into any additional doses of any vaccine. You've gotten a dose and had a practitioner note on your record that you reacted. You're statistically protected to a significant degree, despite the patchwork of public health messaging on the matter, and that's all that matters for now.

Hang in there!
posted by late afternoon dreaming hotel at 9:52 AM on April 2, 2021 [41 favorites]

I recently wrote a long answer to another question about Covid vaccines and allergies with lots of links on this question. The basic advice is you should get a followup vaccine of a different type and the CDC says Johnson & Johnson vaccine is probably your best bet. I'd press your doctor to do more research or skip them and go straight to a Covid vaccine clinic.

For your peace of mind; there's a lot of evidence that suggests even a single dose of Pfizer is very good protection. You want to finish the vaccine eventually, but in the meantime you are way better off than folks who've had no vaccine.
posted by Nelson at 10:18 AM on April 2, 2021 [5 favorites]

Sorry for the bad reaction.

In practice there are not very many things a "passport" or other proof of vaccination will help you do. I think almost literally nothing right now. But even later. I think people are talking about it because it feels good to think about moving around again and the idea that it should somehow be official, and also because they think it might encourage people on the fence if getting vaccinated got you special privileges.

Where it might make sense and be used is for airlines--especially international travel--and certain professions. But those are precisely the things you'll be able to get a medical exception for, especially with having received one shot.
posted by mark k at 11:26 AM on April 2, 2021

I would nth (a) getting documentation from your doctor of this and (b) discuss whether or not J&J is right for you with your doctor.

I think "vaccine passport" is going to become a huge thing within the next few months, actually, so I would want a doctor's note on hand very soon given your situation.
posted by jenfullmoon at 11:28 AM on April 2, 2021 [2 favorites]

Just wanted to say that it’s quite possible, (or even likely?), that the single dose of the Pfizer vaccine is more than 80% effective if you look further out in time than two weeks after that dose. My understanding is that it’s not yet really known how much of the additional effectiveness is coming from the second dose vs how much is simply the first dose having time to work.

Don’t base any decisions on the above, but it may help put your mind at ease!
posted by wyzewoman at 3:17 PM on April 2, 2021

I would honestly, seriously, and with great care suggest crossing that bridge when you get to it. If you'd need to say travel, you have cause to get the second shot. But while you don't, and there is a shortage, your lack of a second shot is for the greater good, since you are both contributing to heard immunity and freeing up medicine for those in need.
I strongly suspect that one shot will be enough soon enough, and an antibody test might be all that is needed to bridge that divide in the interim.
But since this is a worry, rather than a current problem, you're probably best served by acceptance.
I might have missed something of course, and no offense meant. But this is what I'd need to hear in such a situation, so I hope it helps.
posted by svenni at 12:02 AM on April 3, 2021

I agree you should check with your doctor at some point to see if there is any new scientific consensus. There are other people in the same situation as you, and even if it's a small percentage, scientists will be thinking about this problem and researching it, over time.

Here's an article in the NY Times from a few days ago. The headline is "Getting One Vaccine Is Good. How About Mix-and-Match? Researchers are exploring the possible benefits of pairing doses from two different Covid-19 vaccines." The article doesn't specifically mention people who have an allergic reaction to the first dose, but the research answers might also help that group.

The research is being done for two main reasons: to determine whether two doses of different vaccines might be more effective; and to give more flexible options to countries that are finding it difficult to always deliver a second dose of the same vaccine.
posted by daikon at 8:29 AM on April 3, 2021 [1 favorite]

The whole reason for vaccine requirements for those who can be vaccinated is to protect people like you who can't be. Your doctor has likely dealt with this before in other situations (e.g. school vaccination requirements) and should be able to provide some sort of documentation.
posted by Jacqueline at 7:50 PM on April 3, 2021

Response by poster: I did get the J&J vaccine two weeks ago. It took two attempts. The first time, at a pharmacy, they looked up my insurance records and since I had gotten the Pfizer, they said they could only give me the Pfizer. A couple days later, I got it at a drive-up vaccine site, and had me wait 30 minutes (instead of the normal 15) due to my previous reaction with the Pfizer. I had only minor side effects, including about 6 hours of mild flu-like symptoms 4 days after the injection.
posted by Sock, Sock, Sock, Sock, Sock, Goose! at 10:24 AM on May 15, 2021 [2 favorites]