Why Did COVID Symptoms Change Between Variants:

Epicentre News • 09 December 2021

What do researchers say about sympoms changing between variants?

It is theorised that awareness of COVID-19 symptoms may also have changed over time which may have affected people’s reporting (Molteni, Sudre, Canas, Bhopal, Hughes, Chen, & Duncan, 2021).

According to an article in the Conversation, which claims Academic rigour, with a journalistic flair, the way a virus causes illness is dependent on two key factors:

1. Viral factors; which includes things like speed of replication, modes of transmission, and so on. These ‘viral factors’ change as the virus evolves.

2. Host factors: these are specific to the individual who is infected. They include age, gender, medications, diet, exercise, health and stress which can all affect host factors.

Another influencing factors according to this article is:

1. Vaccination: given the higher rates of vaccination coverage in older age groups, younger people are now accounting for a greater proportion of COVID cases, and they tend to experience milder symptoms.

An interesting thing to note is that this article also claims that a runny nose, a relatively rare symptoms in other strains, was claimed as a common symptom in the Delta strain. This may explain the sudden rise in people experiencing a mysterious ‘other’ symptom, but that is unprovable without further research on this data set.

Furthermore, it’s worthwhile noting that this article claims that most of their data was originally coming from patients presenting to hospitals, which may have skewered their results to more serious cases. But Epicentre’s data does not have this problem, as it was all collected outside of hospitals. As we tested at our Drive-through branches, at homes and workplaces.

According to a study which was conducted in the UK and published in May 2021 in the Lancet journal, they found no change in reported symptoms or disease duration between the Alpha or B.1.1.7. Variant and the original covid strain.

This study measured the total number of different symptoms reported over a period of 2 weeks before and 2 weeks after the test, and the relation with asymptomatic infection, defined as users reporting a positive test result but no symptoms in the 2 weeks before or after the test. If you would like to read more about this study, you can click on this link.

However, it should be noted that this study focused on the total number of symptoms rather than the type of symptoms experienced. Furthermore, the Alpha strain has been de-escalated as a variant of concern as drastically reduced circulation. Thus, it is difficult to apply this data to contexts like South Africa, as we have been affected by completely different variants.