Emerging science on Covid-19: 3rd February 2021 update with Dr. Simon Collins
Previous articles in this series are archived here:
"At least one Covid vaccine leads to reduced Covid transmission"
Today's post goes up in order to mark the second really important turning point for all of us (after the announcement of the first vaccine in mid-November) – and this is very significant – there is evidence at last that people who have been vaccinated against Covid are less likely to transmit the virus subsequently. This is the first time such evidence has emerged. Up to now, the big benefit of the different Covid vaccines has been their ability to ensure that most patients would no longer be at risk on an individual basis of developing severe Covid, requiring I.C.U. treatment. The ability however to reduce person-to-person Covid transmission through vaccination is huge news because it benefits not only the patient but also the wider community. This is a game-changer. It will accelerate our emergence from the pandemic.
This good news has been shown to apply to the Oxford/AstraZeneca vaccine. It's not clear yet whether it will apply to the other Covid vaccines (e.g. Pfizer/BioNTech, Moderna). Preliminary data (not yet peer-reviewed) is showing a 67% reduction in positive swabs in those who have received the vaccine.
"Concerns about the increasing the interval between two Covid vaccine doses don't seem to apply to the Oxford/Astra-Zeneca vaccine".
The Oxford vaccine has sustained 76% protection for 3 months, rising to 82% once the 2nd dose has been administered at the 3-month mark. (It remains unclear if it's a good idea to delay the 2nd dose of the more effective, new Pfizer/BioNTech and Moderna vaccines, which use mRNA technology).
"Post-Covid antibodies last at least six months in most patients"
A big UK government-funded study published today is showing that after Covid infection, of those who develop IgG antibodies (90%+ of patients do):
- 99% still have those antibodies at 3 months
- 88% still have detectable antibodies at 6 months.