COVID Booster: Human challenge studies, misinformation, and foreign news coverage

First human challenge results come through

Human challenge studies – which involve deliberately infecting healthy individuals with a pathogen to test vaccines or treatments – are a very controversial issue. On the one hand, they can yield data that no other test can, and if young and healthy volunteers are chosen, the risks are low. On the other, they still carry a much higher risk for volunteers than traditional clinical trials – and they can only generate data on people who are in the lowest-risk groups.

The first set of results from a COVID-19 human challenge study has been published as a pre-print (non-peer reviewed) study.

The trial, which inoculated 34 volunteers aged between 18 and 29 with a tiny amount of SARS-CoV-2, was carried out before vaccines were available, and prior to the rise of the Alpha, Delta and Omicron variants.

Of the 34, 18 (53%) volunteers became infected, and none had serious adverse health effects.

The researchers have been able to study the characteristics of early infection in detail, and they say they’ve found a number of indicators that haven’t shown up in other studies.

Fact-checking can help counter COVID misinformation, but the effects don’t last 

The spread of misinformation related to COVID-19 has been a perennial issue through the pandemic. Can we stem the tide by spreading facts instead?  

A recent study published in Nature Human Behaviour suggests that the answer is complicated.  

Thousands of survey respondents in the US and Great Britain were asked to rate the accuracy of both true and false claims about COVID-19, and were then provided with accurate information to fact-check some of the false claims before rating the claims’ accuracy again.  

Immediately after fact-checking, participants rated the debunked false claims as less accurate. However, the researchers did not find any evidence that exposure to fact-checking continued to decrease participants’ false beliefs a few months later.  

In some ways, countering the impact of misinformation and misperception may prove to be an even greater challenge than the development of new vaccines and therapeutics to combat COVID-19. 

Over half of overseas COVID media coverage focusses on US, UK

Over 53% (apparently an important number this week) of Australian foreign news focussed on the US and the UK, according to a study in Australian Journalism Review.

Only 5% of foreign news focussed on our nearest neighbours in Southeast Asia.

Dr Ross Tapsell, a researcher at the Australian National University’s College of Asia and the Pacific, tracked foreign COVID coverage in the ABC’s 7PM news, ABC’s 7:30 program, and three newspapers – the Australian, the Sydney Morning Herald, and the West Australian.

“Why does the Australian media cover US and UK so comprehensively but rarely covers COVID in our region?” Tapsell asked on Twitter.

“This isn’t a criticism of foreign correspondents’ work (I argue for more). The Australian media has for the past decade reduced its number of reporters in Asia Pacific & has steadily dismantled programmes & positions that allowed for reasonable (if not extensive) coverage.”

COVID-19 boosters and some antiviral medications appear to neutralise Omicron

The Omicron variant has already proved more resistant to COVID-19 vaccines compared to the Delta strain, but new research shows that boosters and the antiviral medications remdesivir and molnupiravir still act in a similar way with Omicron when compared to Delta.

The new paper, published in Nature, has shown that the approximately 36 mutations to the spike protein of Omicron alter how the virus infects cells, and reduces its sensitivity to some therapeutic and vaccine-elicited antibodies.

They analysed the interactions between antibodies and the Omicron spike protein and found that casivirimab and imdevimab, which have been shown to be particularly effective at neutralizing Delta when used together, lose this activity against Omicron.

They also saw a 10-fold reduction its neutralisation compared to Delta after exposure to serum from individuals vaccinated with two doses of either the Pfizer–BioNTech or Oxford–AstraZeneca vaccine. However, sera from individuals boosted with Pfizer–BioNTech as a third dose was shown to increase this neutralisation.

COVID-19 the worst killer in Sweden, Switzerland and Spain since 1918 influenza

A paper published in Annals of Internal Medicine states that in three countries, COVID-19 has caused more excess deaths than any other event in the past century.

The researchers, who are based at two universities in Switzerland, examined mortality data from Sweden, Switzerland, and Spain, from 1851, 1877, and 1908, respectively.

These three countries were chosen because they have essentially consistent mortality data over those time periods, were neutral in both world wars, and haven’t had significant changes in their borders.

In all three countries, the only event which had a greater effect on excess deaths than COVID-19 was the 1918 influenza pandemic.

“Only time will tell what the long-term effect of the COVID-19 pandemic will be,” conclude the authors in their paper.