Thread by @sailorrooscout

Very encouraging data out of South Africa. A study released by NICD shows South Africans contracting COVID-19 in the current fourth wave of infections are 80% LESS likely to be hospitalized if infected with Omicron compared with other strains.

Let’s talk about this and more! 🧵

It is IMPORTANT to note severity of disease in humans is NOT determined only by virus replication but also by the host immune response to the infection. Make sure you are PROTECTED. Regarding sources for the information above:
•bloomberg.com/news/articles/…
•medrxiv.org/content/10.110…

Once admitted to the hospital though, the risk of severe disease doesn’t differ from other variants. Compared to Delta infections in South Africa between April and November, Omicron infections are associated with a 70% LOWER risk of severe disease.

https://twitter.com/miamalan/status/1473635481397215236?s=21

Falling in line with data out of South Africa, early real-world severity data out of the U.K. Health Security Agency (UKHSA) shows Omicron is causing a milder illness than Delta in most Britons, with some VERY important caveats.

https://twitter.com/miamalan/status/1473605883976429575?s=21

Regarding sources for the information above:
•politico.eu/newsletter/lon…
•politico.eu/article/omicro…

U.K. government scientists are set to conclude that Omicron is causing a milder disease than the Delta strain in most Britons. The U.K. Health Security Agency is due to publish its early real-world data on the severity of the disease this week.

The most encouraging news in the early data is that Britons who fall sick with Omicron are LESS likely to become severely ill than those who caught Delta. More people are likely to have a mild illness with less serious symptoms- probably in part due to Britain’s large number of

vaccinated and previously infected people, and possibly because Omicron may be intrinsically milder. Chief Medical Officer Chris Whitty has previously cautioned against too much optimism based on the initial optimistic signs from South Africa in the past few weeks.

However, the UKHSA’s view after studying cases in Britain is that Omicron is indeed usually less severe than Delta. Important Caveat. While Omicron seems to be milder overall, the UKHSA has found it is not necessarily mild enough to avoid large numbers of hospitalizations.

Experts have found evidence that for those who do become severely ill, there is still a high chance of hospitalization and death. UKHSA confirmed that transmissibility of Omicron is very high, meaning that even though it is milder, infections could increase to the point people

still end up in hospital. Great news is, BOOSTERS MAKE A DIFFERENCE. UKHSA is expected to conclude that booster doses SIGNIFICANTLY reduce the chances of BOTH symptomatic infection AND ending up in the hospital with Omicron. So make sure YOU ARE PROTECTED.

The number of people ending up in hospital after testing positive for COVID has decreased to one of the lowest points in the entire pandemic, with just 1.95% being admitted. Similar data regarding mild symptoms and low hospitalizations out of NYC: cnbc.com/2021/12/20/cov…

Summary:
•Difficult to disentangle if less severity is due to prior IMMUNITY (vaccine or natural infection) OR intrinsic virulence of Omicron, BUT Omicron IS causing milder illness
•Vaccine immune escape (in regards to nAbs ONLY), protection against SEVERE infection sustained

•GET PROTECTED. GET BOOSTED.
•Boosters give strong protection against BOTH symptomatic infection AND severe illness
•Don’t walk around IMMUNE NAIVE!
•UPDATE: NEW data out of Scotland reflects findings out of South Africa and UK: research.ed.ac.uk/en/publication…