What are the side effects of the Pfizer vaccine?

side effects of the Pfizer vaccine
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Here, we assess some of the most common side effects of the Pfizer and BioNTech COVID-19 vaccine

Clinical trials have reported that the Pfizer and BioNTech vaccine is 95% effective against SARS-CoV-2.

More recently it has proved to prevent patients experiencing severe COVID and dying from the South African mutation, however it is significantly less efficient in preventing infection of the virus completely.

In a previous article, we addressed numerous rumours about the side effects of the Oxford-Astrazeneca vaccine, but what about the Pfizer vaccine?

Common side effects

Generally, all vaccines come with the risk of side effects. Some of the most common side effects of the Pfizer vaccine include:

  • Tenderness, swelling and/or redness where the injection has been administered
  • Headache
  • Muscle ache
  • Feeling tired (fatigue)
  • Fever (temperature above 37.8°C)

Around 1 in 10 people will experience these side effects.

Uncommon side effects

The more uncommon side effects that 1 in 100 people may experience include enlarged lymph nodes that can last up to 2 weeks, but this can be expected a few days after receiving the vaccine as a sign of the immune system’s response.

A rare side effect that can occur and affects around 1 in 1,000 people may be temporary one-sided facial drooping. Some may also suffer from an allergic reaction, but the data on this is unknown as no cases have been reported.

These side effects are not life-threatening and will settle on their own, however, if you are concerned you can contact your doctor, nurse or local pharmacist for advice. You can also take paracetamol to ease some of the symptoms.

What does the Pfizer vaccine contain?

The active substance in the vaccine is BNT162b2 RNA. After dilution, the vial contains 6 doses, of 0.3 mL with 30 micrograms of mRNA each.

Messenger RNA (mRNA) gives our cells information about what the virus looks like so that it can make good antibodies in response. Unlike some vaccines, mRNA does not contain any fragments of the actual virus.

There have been some concerns about whether or not mRNA can alter a person’s DNA. These rumours are not true. The vaccine simply instructs the body on how to create an organic defence against the virus via information about the virus’ structure.

The other ingredients include:

  • Polyethylene glycol/macrogol (PEG) as part of ALC-0159.
  • ALC-0315 = (4-hydroxybutyl)azanediyl)bis(hexane-6,1-diyl)bis(2-hexyldecanoate)
  • ALC-0159 = 2[(polyethylene glycol)-2000]-N,N-ditetradecylacetamide
  • 1,2-Distearoyl-sn-glycero-3-phosphocholine
  • Cholesterol
  • Potassium chloride
  • Potassium dihydrogen phosphate
  • Sodium chloride
  • Disodium hydrogen phosphate dihydrate
  • Sucrose
  • Water for injections

It should be stored in a freezer at -80 °C to -60 °C and once thawed the vaccine should be diluted and administered by a healthcare professional within 6 hours.

If you know are you allergic to any of these ingredients you should consult your doctor before receiving the vaccine. You should also tell your doctor if you are pregnant or breastfeeding and taking other medicines.

Needle phobia

You can also find help on how to overcome needle phobia here. 

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33 COMMENTS

  1. I had my jab 19/02/21 the phizer bionica. And can report yes the injection site was tender for about 48hrs also around 4hrs after the jab started to feel a bit achy as though i was coming down with something but didn’t get any worse. By the following day it had gone. Within 2-3 days felt perfectly fine and fully back to normal

  2. I had my second dose 2/21/2021 and was tired but next day very very nauseous bad headache and my underarm is still sore and has a red mark like a sunburn. Plus having crazy dreams … I am not sick anymore, but arm still sore.

  3. Had
    my pfyzir vaccine felt like I had a cold coming on and a headache for about 24hrs but was fine after that.
    I wish people wouldn’t scare monger . it’s such a difficult time to make decisions about vaccines and don’t need to hear stories without proof.

  4. Woke up at 4am today shivering uncontrollably with a bad headache and brain ‘zaps’ radiating down both arms. Eyes jerking left and right on their own. Arm injection site very sore. Very weak, struggle to get out of recliner. My first injection had no side effects.
    BP 95/65 pulse 101. Temp 100.

    • Interesting about the brain zaps. I had them about 12 hrs after my first vaccine and they lasted about 4-5 hours along with chills and a headache.. I had my second one yesterday at 4pm. Woke up at 7:30 a..m. with a headache and by 10:00 a.m. I am also having brain zaps every time I move my eyes. I am exhausted and now I’m starting to get cold. I am concerned about the brain zaps. How are you feeling now?

  5. Had my 1st jab on the 19th of feb , all fine till Tuesday, ached on that day on Wednesday had a rash Thursday spoke to a doctor got shingles, pharmacy told they have heard it’s from the vaccine.

    • If you got shingles, it was because you have previously had chickenpox, and the VZV-virus hides in the body.
      It can be reactivated by any stress to the body, such as being otherwise ill, or work/home stress, going on holiday, change in weather, extreme temperatures, a shock, etc. The delay to such a reactivation varies, and certainly might be as little as a week, but is more often 2- 3 weeks, not 4 days.

  6. Had my first jab on Tuesday morning, felt absolutely fine for 2 days no side effects just tired.
    Thursday evening got really hot and had chills for like an hour. Then I got full body little pins and needle feeling and full body itch, still continuing into day 4.

    Advised to take paracetamol and antihistamines- I’m hoping that this will ease. Has anybody else felt this / know how long this may last.

    • I’m the exact same full body itch like crazy bad im looking on here to see if anyone else has the same side effects and how long it may last. Had my 1st jab Pfizer on Thursday I was fine that day but since the following day Friday its been uncontrollable itching and tiredness due to lack of sleep because the itchinh/scratching all night. Anybody know how long this may last please ?????

  7. Thanks for the advice. First AZ today and sat in bed with uncontrollable shaking and slight temperature. Can hardly get out of bed. Glad it’s not just me. Cheers.

  8. Had phizer vaccine began to feel a sore arm later and then spread to all limbs. Went to bed woke feeling freezing cold, later felt so hot temperature of 39. As others have said vivid weird dreams. Really weak for next two days. Nausea, fatigue and slight cough. I have been told 2nd will be worse, but it hasn’t put me off at all. Just bad luck. I had Covid last April for about 12 weeks but not in hospital. Could be a connection?

  9. I got my second vaccine yesterday. Woke up around am today with nausea and vomiting. Fever, chills, body aches. Still 24 hours feel like I have the flu, nauseous, weak.

  10. Had my first vaccine nothing but tiredness until a week later pins and needles, really hot, nausea. Had it for three days so far. Phoning Doctor tomorrow

    • I’m having the same thing. Tingling on the left side of my body but other than that I feel fine. When did it subside for you?

  11. my mother who is 83 is having a terrible reaction to the second vaccination . she had them 3 weeks apart in the first phase . the second vaccination has made her ache all over. feel cold. cant sleep . the strong painkillers from the doctor made her seize up. the vitamin c and d also from the doctor made her nauseous so she stopped . On a morning it talks her 10 minutes to get our of bed. her upper arms are so weak she cannot get herself up easily. she suffers from arthritis and this seems to have made every muscle in her body and every bone ache. only her head is ok as she jokes. from an active 83 year old she has not been out to get her shopping or do anything like sweep the garden path SINCE TEH 5TH JANUARUY . she just sits and keeps warm and complains of aches and pains. had an x ray. nothing internally wrong. so definitely side effect of the vaccine. the first one was ok. just a pain in her arm the last week before her second vaccination was due.

  12. Had my first vac on 19 Feb 21 the next day felt like I was lethargic and feeling annoyed and achy all over my body like having a flu without all the symptoms. Within in 6 hours of the vac my lymph nodes on my left armpit start to swell and sore lasted for about good 5 days. Since Thursday until now I am having a severe rash like reaction all over my body.

  13. i hadmy second shot on3/2/21 after about 10 hours i woke up shaking all over and could not stop my body was not cold but could not stop shaking and had a very bad head ache some nausea the nausea went away the next day. i went to work left before lunch because i could not quit shaking then the headache came back the shaking lasted about 2hours this time then it and the headache went away. then about 10 pm i woke up with another shaking spell which lasted about 30 min i got up and came to work this morning no more symptoms yet i hope they are over .it is a strange feeling to shake like that and not be cold

  14. Had the jab on the 11th Feb and was ok until the 18th when I was wakened in the middle of the night by fairly severe pins and needles in the same (right)arm. It is fading now (after another week) but if it was a reaction to the jab it was not expected.

  15. Had vaccine on 15 Feb, after more or less shaking off “Brain Fog”, dizziness, nausea, blurred vision, sensitivity to light, lost appetite and extreme fatigue after 2 weeks or so I am left with what appears to be permanent severe tinnitus which started 12 hours after jab. Perfectly fit before hand, having the vaccine was the worse thing I ever did. Of course it is impossible to actually see a doctor or get any treatment.

  16. I had my first pyzser (Soz about spelling) about 3 weeks ago felt ok till 24 hours after then began severely shaking all over through the night twice lasted about 30 mins. Weird feeling in head mentally!!!!
    Lymph nodes are swollen and anxiety been up slightly and brain fogginess, words getting jumbled up a lot anyone else experienced this? Was fine beforehand not sure whether to get the second one now? Don’t fancy going through side effects again!

    • Hi Jane,

      Radiologists have confirmed that lymph node swelling is a quite common side effect of the COVID vaccine. If this doesn’t go down by itself, please contact your GP.

  17. I had 2 Pfizer vaccinations and my wife had 2 from Medrona. We both had the same reaction after the second shot namely itching all over the body. We apply Benadryl topically every night and it gives temporary relief. The itching and red spots on the skin have been going on over a month for both of us. How much longer will this go on? She is 85 and I am 95. Noone else seems t have this problem. Thank you. Patrick Zilliacus

  18. This is the 4th week of having Oxford vaccine I can hardly lift my left arm now it keeps me awake the pain going down arm most of night I have been putting hot water bottle on left shoulder to help with the ache in going down my arm this side effects come on 4 weeks after having vaccine shall I consult my dr or will it go I am worried about having 2nd injection now .

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