Here’s what we know so far about the after effects of the Pfizer COVID vaccine
https://covid.joinzoe.com/post/covid-vaccine-pfizer-effects
Here’s what we know so far about the after effects of the Oxford AstraZeneca COVID vaccine
https://covid.joinzoe.com/post/covid-vaccine-astrazeneca-effects
How to tell the difference between COVID-19 symptoms and vaccine after effects
https://covid.joinzoe.com/post/covid-symptoms-or-vaccine-after-effects
Vaccine side-effects and SARS-CoV-2 infection after vaccination in users of the COVID Symptom Study app in the UK: a prospective observational study
https://covid.joinzoe.com/post/covid-vaccine-data-lancet
https://www.thelancet.com/journals/laninf/article/PIIS1473-3099(21)00224-3/fulltext
Pfizer-BioNTech (BNT162b2)
Oxford-AstraZeneca (ChAdOx1 nCoV-19)
Safety and effectiveness in UK community setting
1,607,620 users (2·4% of the UK population)
Methods
Prospective observational study
Self-reported systemic and local side-effects within 8 days
After one or two doses
Infection rates, after vaccine, diagnosed by PCR or lateral flow
Unvaccinated controls
Findings
Dec 8th 2020, and March 10th 2021
Vaccinated reporters, n = 627 383
Reactogenicity, (common, expected)
Systemic side-effects
Fatigue and headache (about 4% each)
Most frequently within the first 24 h
Lasted a mean of 1·01 days
Fever
Chills or shivers
Nausea
Diarrhoea
Muscle pains
Joint pains
Local side effects
Tenderness and local pain
Redness
Swollen armpit glands
Warmth
Itch
Bruising
Pfizer
One dose, 282, 103 (13% SSE) (71.9% LSE)
Two doses, 28, 207 (22% SSE) (68.5% LSE)
Median, 41 days apart
Oxford AZ
One dose, 345 280 (33.7% SSE) (58.7% LSE)
In those with past infection after Pfizer
SSE x 2.9
LSE x 1.2
In those with past infection after Oxford AZ
SSE x 1.6
LSE x 1.4
Vaccinated people who became infected
Vaccine group, 3,106 of 103,622
Unvaccinated controls, 50,340 of 464,356
Reductions in infection risk
Started at 12 days after the first dose, to 21 days
Reaching – 60% Oxford AZ
Reaching – 58% for the Pfizer
Longer term benefits of vaccination after Pfizer
RR, 21 to 44 days – 69%
RR, 45 to 59 days, – 72%
In conclusion, short-term adverse effects of both vaccines are moderate in frequency, mild in severity, and short-lived.
Adverse effects are more frequently reported in younger individuals, women, and among those who previously had COVID-19.
The post-vaccine symptoms (both systemic and local) often last 1–2 days from the injection.
Our data could be used to inform people on the likelihood of side-effects on the basis of their age and sex and the type of vaccine being administered.
Furthermore, our data support results from randomised controlled trials in a large community-based scenario showing evidence of reduction in infection after 12 days and substantial protection after 3 weeks.
Source