The Oxford University/AstraZeneca vaccine has been approved for use for people 18 years or older and consists of two doses, with the second dose administered 4-12 weeks after the first dose. The transportation and storage requirements for this vaccine mean that it needs to be kept at temperatures of 2C to 8C, which is similar to a conventional fridge for up to six months and can be administered within existing healthcare settings.
The UK Government has purchased 100 million doses of this and it likely to be the vaccine that most of us get offered
As with any vaccine or medicine, COVID-19 vaccines require continuous safety monitoring by the MHRA and that the benefits in protecting people against COVID-19 must be greater than any side-effect or potential risks.
The name is: COVID-19 Vaccine AstraZeneca
The dose is: 50 billion viral particles i.e. the full dose
The COVID-19 Vaccine AstraZeneca vaccination course consists of two separate doses of 0.5 ml each. The second dose should be administered between 4 and 12 weeks after the first dose
Immunocompromised individuals. It is not known whether individuals with impaired immune responsiveness, including individuals receiving immunosuppressant therapy, will elicit the same response as immunocompetent individuals to the vaccine regimen.
Pregnancy:There is a limited experience with the use of COVID-19 Vaccine AstraZeneca in pregnant women.Preliminary animal studies do not indicate direct or indirect harmful effects. Administration of COVID-19 Vaccine AstraZeneca in pregnancy should only be considered when the potential benefits outweigh any potential risks for the mother and foetus (More tests are needed). Breastfeeding: It is unknown whether COVID-19 Vaccine AstraZeneca is excreted in human milk. But antibodies can get in to breast milk
Side effects The most frequently reported adverse reactions were injection site tenderness (>60%); injection site pain, headache, fatigue (>50%); myalgia (muscle ache), malaise (>40%); pyrexia (fever), chills (>30%); and arthralgia (joint ache), nausea (>20%). The majority of adverse reactions were mild to moderate in severity and usually resolved within a few days of vaccination. By day 7 the incidence of subjects with at least one local or systemic reaction was 4% and 13% respectively. When compared with the first dose, adverse reactions reported after the second dose were milder and reported less frequently. (Not sure why)
Adverse reactions were generally milder and reported less frequently in older adults (≥65 years old).
If required, analgesic (anti-pain) and/or anti-pyretic (anti fever) medicinal products (e.g. paracetamol-containing products) may be used to provide symptomatic relief from post-vaccination adverse reactions.
Mechanism of action
COVID-19 Vaccine AstraZeneca is composed of a single recombinant, replication-deficient chimpanzee adenovirus (ChAdOx1) vector encoding the S glycoprotein of SARS CoV 2. Following administration, the S glycoprotein of SARS CoV 2 is expressed locally stimulating neutralising antibody and cellular immune responses.
COVID-19 Vaccine AstraZeneca has been evaluated based on an interim analysis of pooled data from four on-going randomised, blinded, controlled trials: a Phase I/II Study, COV001, in healthy adults 18 to 55 years of age in the UK; a Phase II/III Study, COV002, in adults ≥18 years of age (including the elderly) in the UK; a Phase III Study, COV003, in adults ≥18 years of age (including the elderly) in Brazil; and a Phase I/II study, COV005, in adults aged 18 to 65 years of age in South Africa. The studies excluded participants with history of anaphylaxis or angioedema (Swelling); participants with severe and/or uncontrolled cardiovascular, gastrointestinal, liver, renal, endocrine/metabolic disease, and neurological illnesses; as well as those with immunosuppression. In studies COV001 and COV002, licensed seasonal influenza and pneumococcal vaccinations were permitted (at least 7 days before or after their study vaccine).
Based on the pre-defined criteria for interim efficacy analysis, COV002 and COV003 exceeded the threshold of ≥5 virologically confirmed COVID-19 cases per study and therefore contributed to the efficacy analysis; COV001 and COV005 were excluded.
In the pooled analysis for efficacy (COV002 and COV003), participants ≥18 years of age received two doses of COVID-19 Vaccine AstraZeneca (N=5,807) or control (meningococcal vaccine or saline) (N=5,829). Because of logistical constraints (cock-up with the manufacturing and supply) , the interval between dose 1 and dose 2 ranged from 4 to 26 weeks.
Baseline demographics were well balanced across COVID-19 Vaccine AstraZeneca and control treatment groups. Overall, among the participants who received COVID-19 Vaccine AstraZeneca, 94.1% of participants were 18 to 64 years old (with 5.9% aged 65 or older); 60.7% of subjects were female; 82.8% were White, 4.6% were Asian, and 4.4% were Black. A total of 2,070 (35.6%) participants had at least one pre-existing comorbidity (defined as a BMI ≥30 kg/m2, cardiovascular disorder, respiratory disease or diabetes). The median follow-up time post-dose 1 and post-dose 2 was 132 days and 63 days, respectively.
A total of 131 participants had SARS CoV 2 virologically confirmed (by nucleic acid amplification tests) COVID-19 occurring ≥15 days post dose 2 with at least one COVID-19 symptom (objective fever (defined as ≥37.8°C), cough, shortness of breath, anosmia, or ageusia) and were without evidence of previous SARS CoV 2 infection. COVID-19 Vaccine AstraZeneca significantly decreased the incidence of COVID-19 compared to control
Following vaccination with COVID-19 Vaccine AstraZeneca, in participants who were seronegative at baseline, seroconversion (as measured by a ≥4 fold increase from baseline in S binding antibodies) was demonstrated in ≥98% of participants at 28 days after the first dose and >99% at 28 days after the second.
If you have one dose the antibody levels are 7,000-9,000 get a second dose and it jumps to 20,000-40,0000 with interval of few weeks to 3 months gap, if you have been infected the level jumps to 175,000
An immunological correlate of protection has not been established; therefore the level of immune response that provides protection against COVID-19 is unknown.
High seroconversion rates were observed in older adults (≥65 years) after the first (97.8%; N=136) and the second recommended dose (100.0%; N=111).
In participants with serological evidence of prior SARS CoV 2 infection at baseline (GMT=13,137.97 [N=29; 95% CI: 7,441.8; 23,194.1]), S antibody titres peaked 28 days after dose 1 (GMT=175,120.84 [N=28; 95% CI: 120,096.9; 255,354.8]).
If you were infected before you should get a rip roaring vaccine response
Spike specific T cell responses as measured by IFN ɣ enzyme-linked immunospot (ELISpot) assay were induced after a first dose of COVID-19 Vaccine AstraZeneca. These did not rise further after a second dose.
Now to the rubbish of the MHRA and the government’s advisory Joint Committee on Vaccinations and Immunisation They delivered a surprise by announcing approval of a regime that was not trialled. Sorry I have to say this is shambolic, as it makes a mockery of the whole regulatory process. Companies spend millions to do trials for 20 people on some committee to say wouldn’t it be fun to do this instead. I realise it is a National Emergency but I thought the MHRA is about safey and so to do something that has not been tested (for one agent) is rather against this principle….Shambolic.
Apparently both the Oxford vaccine and the Pfizer/BioNTech jab which is already in use will be given to people as one shot, followed by another up to 12 weeks later, in order to extend some protection to as many people as possible as quickly as possible.
Now if you have to wait until 12 weeks to get next dose it means reduced antibody levels for probably 8 weeks. Hopefully this is enough to stop you getting COVID-19/Severe COVID. The bean counters have come up with the view that this allows them to give more people their first dose. This is great but not sure why this approach has been applied to the BioNTech vaccine this was tested with an interval up to 6 weeks whereas information for the Oxford vaccine goes to over 25 weeks. Now the glass half empty view is that it stops people getting sick, but does not stop infection and means that the surving virus gets selected that is not inhibited by the vaccine and oops Ground hogday but thats not going to happen..Let’s hope
A nice low point to end the year on:-(