COVID-19 long haulers, smell tests, and other updates

This week’s highlights go to a relatively unknown face of COVID-19, the role of smell tests in case detection, plus new developments in the vaccines & treatments race.

Enjoy the focused bits of knowledge!

Another face of COVID-19: long haulers

There’s a trend I’ve been hearing for the past few weeks about COVID-19 disease course: the persistence of symptoms for long periods of time. Some people start by having mild symptoms and think they might be up for about two weeks of disease, as this is the norm for younger people without underlying health conditions.

But some of these apparently mild infections can prolong for several weeks or even months, placing an excessive burden on patients, who are now known as ‘long-haulers’. In a piece for the BMJ blog, Paul Garner, a professor of infectious diseases at Liverpool School of Tropical Medicine, discusses his experience of having covid-19 for seven weeks, describing his symptoms that would wax and wane, but would render him exhausted most days. Having some knowledge of the ‘supposed’ timeframe of the disease didn’t help, because he couldn’t place his symptoms and their duration in that timeframe.

And what are those symptoms? Some are familiar—like headaches, shortness of breath, and loss of sense of smell­—but others are more peculiar, like developing a foggy mind, tachycardia, and extreme fatigue. The strangest thing is that the symptoms don’t develop in a continuum, but they come and go, making the patients feel that they’re getting better, only to get worse a couple of days later.

It is still unclear why these ‘long-haulers’ take more time to recover, and it’s also unclear if they are still shedding significant amounts of virus during the entire disease course. This piece of information adds to what we know so far about the weirdness of COVID-19 infection. Only time (and more investigation) will give us the rest of the puzzle pieces.

Smell tests vs temperature checks

Now that two of my boys are back in kindergarten, some things have changed for me. First, I’m slightly relieved of my snack-making and story-reading activities for some hours. Second, there’s a new kindergarten drop-off ritual. I walk them to kindie, but parents can’t go inside the building. Before they go inside, the kids leave their shoes outside (they have another pair just to use there), sanitise their hands, get a temperature check, and off they go.

I’ve been biting my tongue every time they go through the temperature check. I want to tell them about all the people that never develop fever while they’re sick with COVID-19. There are also other causes for fever, although irrelevant in this case (their policy was always not allowing kids with fever, which makes sense).

Bottom line is that a simple temperature check can’t rule out (or in) COVID-19. I believe its widespread use is because it’s a simple thing to do and people feel they’re doing something to prevent SARS-CoV-2 infections.

Anosmia—the medical term for the loss of sense of smell—on the other hand, has been reported in many COVID-19 cases, and this study found 40% anosmic patients among 45 PCR-positive individuals.

A smell test, albeit a little more time-consuming than a temperature check, may be a useful addition to control stations. Not in a kindergarten, but maybe at airports or workplaces. This article sums up nicely the opportunities and challenges of implementing smell tests to detect COVID-19 cases.

Drugs & vaccines

The race to find vaccines and suitable treatments for COVID-19 continues, and this week the spotlight goes to the Pfizer-BioNTech collaboration and to Abivax.

On July 1^st, a BioNTech press release announced early positive data from an ongoing phase 1/2 study for their mRNA-based vaccine candidate against SARS-CoV-2. According with their results, published as a MedRxiv preprint, their vaccine candidate (BNT162b1) was well tolerated and generated dose-dependent immunogenicity, measured by SARS-CoV-2 neutralizing antibody titres, as well as concentration of IgG against the receptor binding domain (RBD) of the virus. You can read more details about the results in the MedRxiv preprint or in this BioSpace article.

On July 2^nd, Abivax announced the treatment of the first patient in phase 2b/3 COVID-19 clinical trial with their ABX464 drug. They claim ABX464 “works via unique triple action: antiviral, anti-inflammatory and tissue repair.” It’s administrated orally once a day, allowing for treatment of both hospitalised and non-hospitalised patients, a clear benefit over other drugs, like remdesivir. The study results are expected by the end of the year, and you can read more about Abivax on their website.

Highlight of the week

EMWA’s journal June issue is now online! If you’re an EMWA member you can expect the physical edition to reach your physical inbox soon, otherwise you can go to the journal website and read the feature articles, they’re all open access.

Do you have any comment or question? Leave me a comment below!