COVID-19
It’s well over two weeks since the last update, and that is the longest interval between updates since COVID-19 began. There has been a lot of information arriving, but often without a clear picture emerging. The WHO Director-General said last week the fact there had been a nearly 90% drop in weekly COVID-19 deaths globally (9400 last week, compared to 75000 weekly in February) provided cause for optimism, but still urged vigilance against the pandemic as variants continue to crop up.
There are now over 300 subvariants in circulation, and not surprisingly the picture remains unclear – you may have seen reference to BQ.1, BN.1, BE.9, BR.2.1, CK.2.1.1 and CH.1.1 amongst others. There is optimism from the BQ.1.1 wave in France where hospitalisations declined despite a wave of a highly immune evasive variants. Similarly in Germany and Italy, increased case numbers were not accompanied by proportionate surges in hospitalisations and deaths. This figure from Fisch reproduced in YLE (Your Local Epidemiologist) gives some sense of the overall patterns:
There are increases in cases in Asia (particularly Indonesia, South Korea and Japan) with concomitant increases in numbers of deaths. There have also been surges in numbers in China, with the Zero-COVID strategy continuing but accompanied by some relaxation of travel restrictions (such as shortened quarantine, reducing from two pre-flight tests to one, and lifting of the “circuit-breaker” bans on airlines with cases). We wait to see how these outbreaks progress.
Meanwhile in the USA, the concerns rest not solely with a possible COVID-19 wave, which may not be eventuating, but with the simultaneous seasonal increase in cases of Respiratory Syncytial Virus (RSV) and influenza as winter sets in.
VACCINES
Concerning vaccines, there has been progressively more information suggesting serological advantage of bivalent booster vaccines, compared with the original “wild type” vaccines – see this summary from epidemiologist Eric Topol:
Meanwhile, this report on boosters was published by Canetti et al in Israel: https://www.nejm.org/doi/full/10.1056/NEJMc2211283
In this prospective cohort study, a third dose of the BNT162b2 vaccine led to an improved and sustained immunologic response as compared with two doses, but the additional immunologic advantage of the fourth dose was much smaller and had waned completely by 13 weeks after vaccination. This finding correlated with waning vaccine effectiveness among recipients of a fourth dose, which culminated in no substantial additional effectiveness over a third dose at 15 to 26 weeks after vaccination. These results suggest that the fourth dose, and possibly future boosters, should be timed wisely to coincide with disease waves or to be available seasonally, similar to the influenza vaccine. Whether multivalent booster doses will result in longer durability remains to be seen.
And another study is included mainly because it was performed with the staff of a Middle East airline, by Moghnieh et al: https://www.mdpi.com/2076-393X/10/10/1596 - “a homologous BNT162b2 booster after a BNT162b2 primary vaccination induced a higher humoral immune response when compared to that induced by a heterologous BNT162b2 booster after a Gam-COVID-Vac primary vaccination. However, the VE of both booster regimens against the Omicron variant was almost equal (64% in the homologous regimen and 57% in heterologous regimen). Hybrid immunity evidenced a better humoral response and a greater and longer protection against Delta and Omicron infections compared to vaccination-induced immunity in COVID-19-naïve individuals. Finally, the findings show that VE waned with time during the same wave, highlighting the importance of reinforcing primary and booster COVID-19 vaccination mainly at the beginning of each wave during the surge of a new variant of concern.”
OTHER COVID-19 STUDIES
Increased excess mortality, mostly due to cardiovascular disease, is reported here in an actuarial study on COVID-19:
https://www.actuaries.digital/2022/11/04/covid-19-mortality-working-group-another-month-of-high-excess-mortality-in-july-2022/
Work continues on possible nasal vaccines (Airfinity) including in China. There has been some evidence that rebound after Paxlovid is much less common than had been feared, and that Paxlovid (nirmaltenivir) may help prevent “long COVID” (Eric Topol newsletter).
The large Veterans Affairs study on reinfection by Bowe et al (https://www.nature.com/articles/s41591-022-02051-3) concluded that the acute and post-acute sequelae of infection are significantly worse in reinfection than in first infection. The major weakness of the study, as identified by the authors, is that because so many cases of infection are not detected, there is considerable scope for misclassification between the groups because of previous mild, undetected infection.
OTHER CONDITIONS (Various sources)
Nepal’s outbreak of dengue fever has reached the highest numbers yet experienced there. Meanwhile, as dengue outbreaks rage in many Asian and Central American locations, a case in Phoenix USA may have been contracted locally.
In Africa, there are concerns that control of malaria is being hampered by the spread of the malaria mosquito Anopheles stephensi, which has been found to be resistant to insecticides.
The ebolavirus outbreak (Sudan strain) in Uganda has reached 160 cases, with almost 80 deaths. Nigeria is reportedly considered to be at high risk according to its Health Ministry, however the global risk is still considered by WHO to be low. There is a WHO EPI-WIN webinar on the Ebola situation on Thursday, 24 November 2022, 14:00-15:00 CET which will be able to be viewed on Youtube afterwards, please visit the EPI-WIN website.
Cholera – during the intense outbreak there, over 2000 cholera cases have been hospitalised in Haiti. There are also outbreaks in Malawi, Syria and Lebanon, similarly consequent on natural and man-made disasters.
And finally, MONKEYPOX. There was a recent paper suggesting that there can be pre-symptomatic transmission of monkeypox. You will have perhaps observed that the case increases have been slowing, with global cases now at almost 80,000 and deaths under 50. Yet a couple of weeks ago, the conclusion of the WHO Emergency Committee meeting on monkeypox was that its status as a PHEIC (Public Health Emergency of International Concern) was extended.
OTHER MATTERS
You may have seen in media about a technical report from CEN (the European Committee on Standardization) on prevention of exposure to cabin air fumes – there are recommendations on improvements in design/maintenance/ops. See https://eturbonews.com/european-transport-union-demands-new-cabin-air-safety-standards/ for press report. The recommendations include: filtration (pending available technology – this was one of the areas which was opposed, since the technology doesn’t exist so far); chemical sensors (similarly – pending available technology); “best practices in maintenance” including avoiding over-servicing; reporting systems; and education.
Best wishes,
David Powell
IATA Medical Advisor