Thread by @chrischirp

THREAD on what other countries are doing in terms of vaccinating 12-17 children... who's doing it and why?

TLDR: UK one one of the v few high income countries left that isn't 1/20

Almost first off the block in vaccinating 12-17 yr olds were USA and Canada in May.

Canada emphasises the importance of vax to protect kids from acute Covid, prevent long term impacts from covid (eg long covid) and reduce transmission to others.

canada.ca/en/public-heal… 2/20

US Centers for Disease Control (CDC) published a risk benefit analysis, projecting forwards for 120 days using May case rates & estimating how many infections, hospitalisations, deaths were prevented vs new harms from myocarditis. 3/20

They found clinical benefit for 12-17 yr olds.

Since May, case rates are way higher in the US, which will further tip benefit to vaccination (since more cases are prevented for same number of people vaxxed).
cdc.gov/mmwr/volumes/7… 4/20

CDC also considered indirect benefits: protecting education, reducing transmission, reducing chance for variants. Also equity since minority ethnics groups more exposed and vulnerable to Covid.

They recommended vaccination of teens. 5/20

As summer progressed, the v low frequency of myocarditis after vaccination became better understood (JCVI now estimates 12- 34 cases per million 2nd doses of vaccine in 12-15 yr olds).

It also seems that in the short term, people recover quickly and it's relatively mild. 6/20

That said, we don't know what the long term looks like for myocarditis after vax.

More evidence has also emerged about risks of myocarditis after Covid but exact risks in teens still unclear. 7/20

nejm.org/doi/pdf/10.105…
cdc.gov/mmwr/volumes/7…

The US has now given at least 1 dose to over half of 12-17 year olds & experts there think it has gone well (@PeterHotez explains below).

Big variation by state though! 8/20

Where vax levels are lower & school mitigations worse, cases in kids in US are soaring. Pediatricians are worried about long term impact given num of infections, even tho severe illness rare.

CDC also showed that unvaxxed teens 10x more likely to need hospital than vaxxed. 9/20

And other countries? Apart from USA & Canada other countries vaccinating 12-17 year olds include:

Israel, Indonesia, Japan, Philippines, Mexico, Brazil, Chile, NZ, Australia, Dubai, UAE, Singapore, Hong Kong...

And what about Europe? 10/20

In early July countries were evenly split on whether to vax teens - 16 did and 17 did not.

voanews.com/covid-19-pande… 11/20

France was an early adopter, deciding to vax teens in June.

Their reasons included clinical benefit to child, but also to protect education & reduce transmission.

They cited evidence from 6m vaxxed in USA by June & that we are in an epidemic... 12/20

reuters.com/world/europe/f…

..which is relevant cos they expected cases to go up a lot on return to school in context of Delta and so there was a time frame for making that decision...

Since then almost all other European countries have started (at least 29) inc Italy, Portugal, Spain, Ireland... 13/20

Germany was one of the last on 16 Aug. They moved from a position very similar to that of JCVI to say that evidence from by then 10m vax in US, mild myocarditis from vax, concerns about myocarditis from Covid and Delta surge had changed the equation towards vax. 14/20

Interestingly Germany also one of the few countries who, like JCVI, only considered direct clinical benefit.

The most recent country to decide to vax is Norway on 4th Nov (prev they'd been doing vulnerable teens).

They cited direct benefit & reduced transmission. 15/20

So UK is now a definite outlier internationally in not using summer to offer vax to all 12-15 yr olds before return to school.

Also unusual in not having indirect benefits part of the remit of advisory body (not up to JCVI btw!). 16/20

As children in England return to schools, cases & hosps in school age children higher than ever.

Almost half of children in hospital, and a third with the late severe complication of PIMS TS, had no underlying health conditions. 17/20
medrxiv.org/content/10.110…

The other thing is that hospital and ICU admissions are disproportionately among minority ethnic & deprived communities - so allowing high infections and no vax, affects BME children & those from deprived communities more.

CDC explicitly considered this in their decision. 18/20

UK is an international outlier in not vaxxing all teens. We weren't in July, but we chose to wait longer than others for more data. Problem is waiting months will expose 1000s children to Covid.

That's the epidemic bit factoring into decisions of several countries. 19/20

Finally, I do disagree with JCVI decision. But also clear that their remit is narrower than many other countries.

I hope that this (still quite shallow) dive into international decisions is useful and shows the subtly different factors other countries have considered. 20/20

PS England is also an international outlier with respect to schools - see this thread

https://twitter.com/chrischirp/status/1428726724934635527?s=20