IATA Medical Contact Group - update COVID-19

Firstly, a request for your input please – for those of you who are airline medical advisors, would you please be able to complete a very short survey which has been compiled by Dr Rui Pombal at TAP, on your role within the airline:  https://www.surveymonkey.com/r/XH95JLG  

WHO reports that COVID-19 cases are increasing in 50 countries, despite rapidly declining rates of testing, but that so far deaths and hospitalisations are increasing much less, and remain at much lower levels than in previous waves.  Areas with low levels of vaccination remain vulnerable, and a number of concerns remain over access, especially in low-middle income countries, to vaccines and anti-viral treatments. 

EASA and ECDC have published an updated version of the Aviation Health Safety Protocol (AHSP), found at the following link: https://www.easa.europa.eu/document-library/general-publications/covid-19-aviation-health-safety-protocol

There is in particular, modified advice on mask wearing and distancing, in parallel with reduced recommendations for cleaning and dinsinfection.  You may find more information at the following link: https://www.easa.europa.eu/newsroom-and-events/press-releases/easaecdc-take-first-steps-relax-covid-19-measures-air-travel

WHO estimates, in keeping with some previous published estimates, that global COVID-19 deaths are at least 15 million to date.

COVID-19 RESEARCH:

The UK “COV-BOOST” study on booster effectiveness found that “peak responses after the fourth dose were similar to, and possibly better than, peak responses after the third dose.”  Munro et al:  https://www.thelancet.com/journals/laninf/article/PIIS1473-3099(22)00271-7/fulltext 

A pre-print article from a small group at Harvard suggested that contrary to the conclusions of most papers so far, Omicron is as severe (in terms of hospitalisations and deaths) as previous variants, after controlling for demographics, co-morbidities and vaccination status - Strasser et al: https://www.researchsquare.com/article/rs-1601788/v1   However, this conclusion depends heavily on the denominator of case numbers, which may be underestimated to a much greater degree since the emergence of Omicron.

Aircraft wastewater analysis detected Omicron entering France in December 2021 even though passengers had tested negative – Le Targa et al: https://www.medrxiv.org/content/10.1101/2022.04.19.22274028v1

BlueDot summary on BA.2.12.1 (increasing in USA), BA.4 and BA.5 (both increasing in South Africa) –
Early data suggest that all these new Omicron subvariants spread faster than BA.2, but there is still insufficient evidence to conclude whether they could cause more severe disease. Protection against severe disease among those vaccinated and/or previously infected is likely to remain consistent with previous variants. However, the impact of cumulative re-infections on disease severity over time among populations is not well understood. 

Cao et al pre-print on BA.2.12.1, BA.4 and BA.5 escape antibodies elicited by Omicron infection - https://www.biorxiv.org/content/10.1101/2022.04.30.489997v1

“Together, our results indicate that Omicron can evolve mutations to specifically evade humoral immunity elicited by BA.1 infection. The continuous evolution of Omicron poses great challenges to SARS-CoV-2 herd immunity and suggests that BA.1-derived vaccine boosters may not be ideal for achieving broad-spectrum protection.”

Carazo et al Canada https://www.medrxiv.org/content/10.1101/2022.04.29.22274455v2.full.pdf on vaccine effectiveness post infection. 

Without vaccination, prior non-Omicron infection reduced the Omicron re-infection risk by 44% overall, but protection decreasing (from 66% at 3-5 months to 35% at 9-11 months post-infection, and less thereafter).  The more severe the prior infection, the greater the risk reduction (8% for prior asymptomatic, 43% for symptomatic ambulatory, and 68% for hospitalized).  

See table for mRNA vaccine effectiveness against Omicron infection:

mRNA vs Omicron total infection

1 vax dose

2 vax doses

3 vax doses

Prev Infected

65%

68%

83%

Not prev infected

20%

42%

73%

 And note the effect of successive doses, at preventing hospitalisation:

Prev infection protection vs Omicron hospitalisation 

No vax

1 vax dose

2 vax doses

3 vax doses

81%

86%

94%

No waning 11 mths

97%

(no difference from 2)

 

Over two-thirds of children in the US are estimated to have been infected with SARS-CoV-2 according to estimates derived from lab samples by CDC – Clarke et al: https://papers.ssrn.com/sol3/papers.cfm?abstract_id=4092074   

 

OTHER:

The number of unexplained hepatitis cases in children is around 350 cases, with some liver transplants and a small number of deaths.  Of the 20 countries reporting them, only 6 countries have reported 5 or more cases, and around 160 cases have been in UK.    Although studies have not yet clearly confirmed a causative agent, infectious or otherwise, adenovirus was identified in a large proportion of the UK cases.  There also is some evidence of increased risk in those who are positive for COVID-19.

The new Ebola virus outbreak in central Africa has so far registered three cases, all fatal (one was a high risk contact of the first one, and tested positive just over a week after being vaccinated). 

Meanwhile, currently, 38 human cases of Japanese encephalitis have been reported in Australia this year with 4 deaths.

Finally, details of the 2022 Cabin Ops Safety Conference (COSC) to be in Lisbon, Portugal 14-16 June, are here: https://www.iata.org/en/events/cabin-ops-safety-conference/     Later in the year is the Aviation Health Conference, in Paris, France 20-21 September: https://quaynote.com/conference/aviation-health-2022/

 

Best wishes,
David Powell
IATA Medical Advisor