A new CDC report on waning of third dose – efficacy against emergency room attendance/hospitalisation declines from 87/91% (2 months) to 66/78% (four months). Ferdinands et al: https://www.cdc.gov/mmwr/volumes/71/wr/mm7107e2.htm This is consistent with earlier results from the UK Health Security Agency.
And a US study with several CDC authors, a case-control design looking at hospitalisation vs vaccination status, here – Lauring et al https://www.medrxiv.org/content/10.1101/2022.02.06.22270558v1 This showed that 2 doses of vaccine provided 65% effectiveness against hospitalisation with Omicron. However, 3 doses provided protection against hospitalisation with Omicron similar (86%) to that provided by 2 doses against Delta or Alpha (85%). It confirmed severity was higher for Delta, than Alpha, and lower for Omicron. In all cases, severity was lower amongst the vaccinated.
Similar results are available in this JAMA article, Accorsi et al: https://jamanetwork.com/journals/jama/fullarticle/2788485 with 3 doses reducing the risk of Omicron by 67% and of Delta by 93%, compared with no vaccination.
Also, a German study with favourable results in terms of duration of serum neutralisation against Omicron in elderly boosted people – Vanshylla et al: https://www.medrxiv.org/content/10.1101/2022.02.02.22270302v1.full.pdf
Some studies similar to previous ones, showing reduced protection against Omicron but improvement with boosters – from Portugal Kislaya et al: https://www.medrxiv.org/content/10.1101/2022.01.31.22270200v1 and from Netherlands, Andeweg et al: https://www.medrxiv.org/content/10.1101/2022.02.06.22270457v2
ECDC considerations on face masks in the community: https://www.ecdc.europa.eu/sites/default/files/documents/Considerations-for-use-of-face-masks-in-the-community-in-the-context-of-the-SARS-CoV-2-Omicron-variant-of-concern.pdf
And ECDC has reported favourably on boosters in adolescents: https://www.ecdc.europa.eu/en/news-events/covid-19-vaccines-adolescents-offer-very-high-level-protection-against-infection
Possibly useful in your airlines, from WHO, is this recent presentation summarising where we are with Omicron and vaccines: Update on COVID-19 vaccines & immune response: 3 February 2022
According to a recently published case study that has not yet been peer-reviewed, the first evidence of hamster-to-human transmission of the SARS-CoV-2 virus, (similar to the much earlier isolated reports showing mink-to-human transmission) has been reported. The study is reported here: https://papers.ssrn.com/sol3/papers.cfm?abstract_id=4017393 and also here: https://www.nature.com/articles/d41586-022-00322-0
And here is a piece in Nature talking about how to get better incidence numbers, including random sampling, now that reported case numbers have become progressively less reliable: https://media.nature.com/original/magazine-assets/d41586-022-00336-8/d41586-022-00336-8.pdf
Best wishes,
David Powell
IATA Medical Advisor