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Really interesting data coming out of latest report on Oxford/AZ vaccine efficacy trials (another one!).
A little
on this.
#COVID19 #CovidVaccine
https://papers.ssrn.com/sol3/papers.cfm?abstract_id=3779160
A little
on this.#COVID19 #CovidVaccine
https://papers.ssrn.com/sol3/papers.cfm?abstract_id=3779160
What did they find?
Trial looked at protection & immunogenicity for participants enrolled between Oct 2020 & Jan 2021. This is period when B.1.1.7 lineage ('UK' variant) started circulating in the UK.
Protection against B.1.1.7 lineage was ~75%
Against non-B.1.1.7 it was ~84%
Trial looked at protection & immunogenicity for participants enrolled between Oct 2020 & Jan 2021. This is period when B.1.1.7 lineage ('UK' variant) started circulating in the UK.
Protection against B.1.1.7 lineage was ~75%
Against non-B.1.1.7 it was ~84%
So what does this mean?
It looks like the vaccine is maintaining a good level of efficacy against the B.1.1.7 variant. But it is reduced.
Interestingly this is pretty much the same reduction seen with Novavax (~96% to ~86%). https://ir.novavax.com/news-releases/news-release-details/novavax-covid-19-vaccine-demonstrates-893-efficacy-uk-phase-3
It looks like the vaccine is maintaining a good level of efficacy against the B.1.1.7 variant. But it is reduced.
Interestingly this is pretty much the same reduction seen with Novavax (~96% to ~86%). https://ir.novavax.com/news-releases/news-release-details/novavax-covid-19-vaccine-demonstrates-893-efficacy-uk-phase-3
Another important finding was detection of lower viral load in vaccine recipients compared to those who got the control vaccine.
So good news as this may translate to a reduction in transmission in those vaccinated.
So good news as this may translate to a reduction in transmission in those vaccinated.
But it gets very interesting when they looked at immunogenicity.
'Virus neutralisation activity by vaccine-induced antibodies was 9-fold lower against the B.1.1.7 variant than against a canonical non-B.1.1.7 lineage'
'Virus neutralisation activity by vaccine-induced antibodies was 9-fold lower against the B.1.1.7 variant than against a canonical non-B.1.1.7 lineage'
Why does this matter?
Well it suggests that protective efficacy can be maintained to some extent even with a reasonable drop in neutralising antibodies.
But we would also assume that the drop in efficacy may relate to the drop in neutralisation activity.
Well it suggests that protective efficacy can be maintained to some extent even with a reasonable drop in neutralising antibodies.
But we would also assume that the drop in efficacy may relate to the drop in neutralisation activity.
What about other vaccines?
An interesting comparison is what was seen with neutralising activity using sera from Pfizer and Moderna vaccine (great study from the Ho lab). Only showed an ~2-fold reduction in neutralising titre against B.1.1.7.
An interesting comparison is what was seen with neutralising activity using sera from Pfizer and Moderna vaccine (great study from the Ho lab). Only showed an ~2-fold reduction in neutralising titre against B.1.1.7.
So does this mean Pfizer & Moderna will perform better against B.1.1.7? No idea!
Might have predicted a bigger impact of efficacy for such a reduction in neutralising activity for AZ vaccine, but note studies use a pseudovirus system, may not replicate results with 'real virus'.
Might have predicted a bigger impact of efficacy for such a reduction in neutralising activity for AZ vaccine, but note studies use a pseudovirus system, may not replicate results with 'real virus'.
It also excludes differences in the ability of these vaccines to induce T cell responses, if you head over to @profshanecrotty feed there is plenty of excellent info on the potential role of T cells.
So overall, very interesting times ahead as more data emerges!
So overall, very interesting times ahead as more data emerges!
