British data would show that the main symptoms of a covid infection have changed dramatically. They are perceived as milder and have gradually become more like cold symptoms. That is hardly surprising, thinks Steven Van Gucht, virologist at Sciensano. He explains why.
–
Of Britse app Join-ZOE assesses the symptoms experienced by people with a covid infection on a daily basis. It is a collaboration between King’s College London University and the pharmaceutical company ZOE. About four million people use the app to keep track of their possible symptoms of a Covid-19 infection on a daily basis. This showed that ‘new symptoms’ of an infection had been reported for a month.
‘A virus can evolve over time’, agrees virologist Steven Van Gucht, ‘but it is very important to be careful when interpreting these data. I see three possible explanations for those milder symptoms.’
1/ Larger share of young people become infected
‘When the elderly become infected, they usually show more severe symptoms than young people,’ says the virologist. ‘Over the past months and weeks we have seen a rejuvenation of the people who are infected. A third of the infections occurred in people in their twenties in the past week. Then it is quite normal that you notice much milder complaints.’
Van Gucht explains: ‘In the elderly, corona infection more often leads to oxygen deficiency or pneumonia. In young people, such an infection is in many cases limited to an infection of the nose. She often passes without any symptoms.’
2/ Vaccination protects against severe symptoms
‘Occasionally, people who have been vaccinated can still contract an infection,’ says Van Gucht. ‘Even then we see milder complaints: infection of the nose, some laryngitis…’
This is clearly evident from the results of the British app. After a full vaccination, people who do become infected report headaches (primarily, just like unvaccinated people), a runny nose, sneezing and sore throat as the main symptoms.
Sore throat is in second place among the unvaccinated. A runny nose, fever and persistent cough complete the top five.
3/ Virus variants
Covid often causes vague complaints, but loss of smell and taste is rather exceptional with other viruses, according to Van Gucht. The complaint is still the fifth most reported symptoms for vaccinated people, while it has fallen to number 9 among the unvaccinated. Breathlessness has even tumbled all the way to thirtieth place for the latter group.
The authors who app results proposals clearly see the influence of the new variants in such shifts. Van Gucht does not want to go that far. ‘You have to come up with hard evidence for that. I’m not ruling it out, but there are just too many other factors that influence these results, the age of the infected people for example.’
‘Symptoms are subjective’
Another caveat to the results is whether they are objective enough. ‘A symptom is something you feel and describe yourself, which is subjective and can change under social pressure. When everyone talks about a sore throat, you feel a sore throat more quickly. But with larger numbers, such as in the app, the quality of the data starts to improve’, says Van Gucht.
‘It is interesting data, but you have to be careful with conclusions. It is normal for a virus to evolve over time’, concludes the virologist.
To what extent should we then rely on those new lists of main symptoms? With every runny nose with some headache, should we get a test, instead of brushing it off like a mild cold?
‘That’s nothing new’, Van Gucht says sternly. ‘Since we have our testing capacity in order, you should actually be tested for symptoms of a cold. That has been the case for over a year now.’
Some people then get a swab in the nose every two weeks. Isn’t that an exaggeration? ‘Certainly in the autumn, when there are many cold complaints, this means that some people have to be tested very often. That can act as a brake on the system’, admits Van Gucht. ‘However, rapid testing is necessary to keep yourself and those around you safe. Testing doesn’t hurt, it doesn’t cost any money, the test centers are open… Just do it.’
‘In Belgium we test 60,000 to 70,000 people a day. Internationally, that is a high figure, but we do not see many cases. Many people shed the virus without knowing it. That is why we keep asking for masks to be worn on public transport, for example.’
– .
