All of my loose ends relate to vaccines and variants, in particular efficacy of the various vaccines against severe disease arising from the new variants of concern and efficacy of the various vaccines against transmission for even the current B.1.1.7 variant let alone the SA/Brazil/other variants. Here Chile seems to be a very interesting and somewhat alarming test case and I wonder what other people here think about what is going on there. Is it a cause for genuine concern in terms of what might happen in the UK later this year or might there be peculiar factors in Chile that are causing it to see this second wave, severe enough for it to re-enter lockdown, despite it's seemingly extremely good vaccination program?
Here is just one article about the Chile situation from just over a week ago - https://www.theguardian.com/global-deve ... on-success
I was actually totally unaware of this news until I watched Boris's news conference yesterday and one of the journalists asking a question mentioned it. Is it just me or has this had relatively low billing in the UK media?
For convenience some selected (by me) key points from the article above are...
Despite mounting the world’s fastest per-capita Covid-19 vaccination campaign, Chile has been forced to announce strict new lockdowns as it plunges deeper into a severe second wave of cases which is stretching intensive care capacity.
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Nearly half of the South American country’s population has received at least one vaccine dose, but on Friday, Chile recorded 7,626 new cases over a 24-hour period – the highest total at any point during the pandemic – and it is now approaching 1m cases in total.
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... Only 169 intensive care beds remain available nationwide – an occupancy rate of more than 95%. ...
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More than 6 million people have received at least one dose of either the Chinese Sinovac or US Pfizer-BioNTech vaccine, and 3.2 million have had both jabs.
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“The issue with communication is that it hasn’t been consistent across government,” explained Aguilera. “While the health ministry has repeatedly called on people to look after themselves, the economy minister has been opening casinos, gyms and cinemas.”
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However, with international travel still allowed, many Chileans took advantage of cheap flights to Miami, Brazil, the Dominican Republic and other destinations, causing the government to tighten restrictions for returning travellers – but not until after the summer holiday season was over.
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Probably clutching at straws but one explanation that would be encouraging for the UK would be if the Sinovac vaccine isn't particularly good and/or if widespread handling issues with the Pfizer vaccine blunted its average efficacy. Then again, we still have unanswered questions about the efficacy of one of our mainstay vaccines (Oxford/AZ) regarding efficacy against the SA variant in terms of severe and fatal disease.
Another factor is Chile at least being on the same continent as Brazil so maybe far more exposure to an E484K-carrying variant such that it is very prominent in the country whereas in the UK we do seem to be keeping the SA variant in bay. As I suggested in a reply to Mike (Mike4) yesterday the PM press conference yesterday did give numbers for new variants in the UK and they are on slide 4 from yesterday's briefing (https://assets.publishing.service.gov.u ... ation_.pdf).
From that data on total "genomically confirmed and probable" cases we have 544 out of a total of 173,586 being variants carrying the E484K mutation (that's 0.3134%) and the new cases since 24th March is +62 E484K carrying cases out of a total of 17,575 new cases so that's 0.3528% of new cases being E484K carrying variants. That actually looks pretty encouraging to me, the percentage of new variants of concern is still very low in the UK and that means that, if it stays that way, then even if the AZ vaccine is way less effective against those variants the overall reduction in efficacy across the whole UK vaccinated population will be low. So far the rate of E484K carrying variants in new cases since 24th March is pretty much in line with the overall percentage so these new variants, at least for now, don't seem to be building much of a beachhead here in the UK but if they are able to escape the vaccines far better than the B.1.1.7 variant can then that balance could change over time - how much time I have no idea. The press briefing also said that a lot of those E484K positives were from quarantine testing of incoming travellers from red zones and to me those positives seem far less worrying since the carriers did not get into the community but went straight into enforced hotel quarantine.
My personal take-away from this is that we really shouldn't have too much hope for much summer international travel, and maybe it is partly this Chile experience that is causing the government to send out quite so many signals to this effect at the moment. Personally I also wouldn't be at all surprised to see at least the 21st June final unlock stage delayed or happen as scheduled but not be quite such a big relaxation as is currently proposed. I also wonder whether the 17th May unlock really will allow rule-of-6 meetings in private homes as is currently intended (https://www.gov.uk/government/publicati ... 21-summary). To me it would seem to make sense to assess the effect of rule-of-6 in theoretically Covid-safe controlled indoor environments such as pubs, restaurants etc for 5 weeks and maybe delay blanket rule-of-6 indoors until the 21st June unlock stage. ANd maybe booster shots in September onwards are more essential than I was perhaps thinking before I became aware yesterday of what was going on in Chile.
Sorry, long post, but I think Chile is an important "battlefield" to analyse when it comes to the fight against SARS-CoV-2 especially when looking at a strong vaccination program vs the virus.
- Julian