Thread by @dgurdasani1

Really worried about the direction things are moving in globally. BA.2 and BA.1.1. seem to be sweeping to dominance in different regions rapidly. Pandemic growth has also resumed in many places including England, & more recently Gauteng. A thread looking at the current evidence.

Remember that the virus is continuously mutating and evolving. There are 4 sublineages of omicron currently identified BA.1, BA.2, BA.3, and BA.1.1. There are several differences between these. e.g. BA.1.1 has the R346K mutation additional to BA.1.

BA.2 differs on several positions. An important one for detection is the deletion that allowed us to initially detect omicron on some PCR tests as 'spike gene drop out' or SGTF. This means that BA.2 will *not* appear as SGTF (unlike BA.1 that does)

BA.2 is now growing to dominance rapidly against a BA.1 background in many parts of the world - Denmark and Gauteng (where it is dominant now)- suggesting it has a growth advantage over BA.1. It has rapidly gained dominance in Denmark, where cases continue to rise.

Data from Denmark appear to suggest a considerable growth advantage - potentially 1.5 fold of BA.2 over BA.1. This will mean faster pandemic growth, and make it harder to contain this even with NPIs.

In Norway, *both* BA.2 and BA.1.1 seem to be rising against a BA.1 background - which is declining. This will be an important context to understand the relative advantages of BA.2 and BA.1.1 against each other given BA.1.1 is rapidly rising in the US as well.

BA.2 has become dominant in Gauteng, where cases
are rising again (just 2 months after the omicron outbreak).

In England BA.2 rising rapidly. B.1.1 has also been rising, but looks lie BA.2 is outcompeting all (not visible on this graph but can be seen in the SGTF ONS data in the linked tweet) - ~5.5% of cases and rising.

In the US, BA.1 seems to be being rapidly replaced by BA.1.1 in some states

So what we're seeing is newer sublineages of omicron outcompeting previous ones. The advantage of one over the other is unclear- it could be 1) escape (i.e. BA.2 or BA.1.1 escape immunity better) or 2) transmissibility

The UKHSA data suggests vaccine efficacy is similar for BA.1 & BA.2 - this means that at least vaccines against the original virus are similarly protective against BA.1 and BA.2 (i.e. much lower VE than delta, but not different between the 2 sublineages)

Of course this doesn't really tell us about the protection to BA.2 infection among those who very recently got infected with BA.1. It'll be important to understand this, but it is possible that the advantage is being driven by increase in intrinsic transmissibility

Overall, this isn't good- what we're seeing is rapid adaptation, and emergency of sublineages, fitter than the original, which means it becomes very hard to contain the pandemic, as the virus gets fitter. Bizarrely we're easing mitigations in England in the middle of this!

Drops in cases have plateaued in England and cases are now at ~100K/day. And BA.2, which seems to have a significant growth advantage is rising to dominance, just as we have dropped plan B measures and school mitigations. What could possible go wrong?

To make things worse, UKHSA vaccine report paints a dire picture with vaccine efficacy, even for severe disease waning significantly over time. Remember that a reduction in vaccine efficacy 96% to 88% (Delta 2 dose vs omicron booster) was a 3x increase in risk.

Now, it seems that protection even against hospitalisation wanes even further at 10+ weeks. While 70-80% protection sounds great, remember this is a *huge* reduction from where we were with delta, and will have significant impact on hospitalisation rates at population level.

Protection against infection is even lower, and wanes even more. Even protection against mortality appears to wane, but lots of uncertainty around these estimates so need to be viewed with caution.

Overall, we seem to be in a continuing pandemic, with very high case numbers, 1,800 COVID-19 deaths/wk (no sign of these reducing yet). And fitter lineages on track to become dominant in the coming weeks, at the point we've eased all mitigations and cases are at 100K/day.

The situation is dire across the world after all the claims of 'mildness' and endemicity. You just need to look across Europe, the US, and Israel to see that the cases have sadly translated into many people who have been severely ill and thousands of preventable deaths.

In the middle of this bizarrely much of the media is talking about the pandemic as if it's over, when in fact there doesn't appear to be an end in sight - at least in much of the Western world which has massively screwed up it's response.

To the 'but it's mild' cabal, unfortunately the sheer numbers of cases are translating to severe pressures on health systems and increase in the number of preventable deaths, as many of us said would happen (but were ignored).

Rather than acknowledging we need to adapt to this quickly by putting in place long-term measures like better ventilation, changing the way we work (more working from home), high grade masks in indoor & crowded spaces, we're continuing to be in denial.

We can contain this- this is an airborne virus. Many countries have done this far more successfully than we have. But the biggest threat we face now isn't SARS-CoV-2. It's denial that we need change and long-term solutions. Denial will prolong the pandemic and kill many more.

We need a suppression strategy. This level of illness, death, mass disruption of healthcare systems and education isn't something we can and should live with. We can do so much better. Why aren't we? We're still continuing to rely solely on vaccines even as we watch efficacy wane

Every time a new variant of concern emerges our vaccines become less and less robust and durable, but we're doing nothing to manage the huge uncertainty associated with this. We need suppression strategies. Countries that have done this are doing *much* better.

This is really the only way of 'living with it' that's sustainable and feasible. It's better for health, economy, society. Why aren't we doing this? An appeal to journalists- please stop platforming deniers.

We need solutions, but we can't even discuss these if the narrative is 'it's over'. We need to move on from this part of narrative to discussing long-term solutions, but that needs us to stop normalising what is a pandemic and a crisis, so we can act.

If you believe 'it's over', just look around you- talk to healthcare workers, teachers, parents, those living with long COVID, carers, clinically vulnerable people, frontline workers. It isn't over. Not by a long shot.