Allegation: “Face masks do not work”
Wearing a face mask is certainly not a foolproof guarantee that you will not get sick – viruses can also be transmitted through the eyes and tiny viral particles, called aerosols, can penetrate the masks. However, masks are effective at capturing droplets, which are the primary route of transmission for the coronavirus, and some studies have estimated protection approximately five times over the lack of a barrier alone (although others have found levels lower efficiency).
If you are likely to be in close contact with an infected person, a mask reduces the risk of transmission of the disease. If you have symptoms of coronavirus or have been diagnosed, wearing a mask can also protect others. Masks are therefore crucial for health and social care workers who care for patients and are also recommended for family members who need to care for a sick person – ideally the patient and caregiver should have a mask.
However, masks will likely make little difference if you’re walking around town or taking a bus, so there’s no need to buy a huge amount in bulk.
Affirmation: It turns into a more deadly strain
All viruses accumulate mutations over time and the virus that causes Covid-19 is no different. The spread of different strains of a virus depends on natural selection – the versions that can spread the most quickly and replicate effectively in the body will be the most “successful”. This does not necessarily mean the most dangerous for people, since viruses that quickly kill people or make them so sick that they are incapable may be less likely to be transmitted.
Genetic analysis by Chinese scientists from 103 samples of the virus, taken from patients in Wuhan and other cities, suggest that at the outset two main strains emerged, designated L and S. Although the L strain appears to be more widespread than the strain S (approximately 70% of the samples belonged to the first), the S branch of the virus turned out to be the ancestral version.
The team behind this research suggested that this could indicate that the L strain is more “aggressive”, either by transmitting more easily or by reproducing faster inside the body. However, this theory is speculative at this point – there has not yet been a direct comparison to see if people who catch a version of the virus are more likely to transmit it or suffer from more severe symptoms.
Statement: “It is no more dangerous than winter flu”
Many people with coronavirus will experience nothing worse than the symptoms of seasonal flu, but the overall profile of the disease, including its death rate, seems more serious. At the start of an epidemic, the apparent mortality rate can be overestimated if many mild cases are missed. But this week, a WHO expert suggested that this was not the case with Covid-19. Bruce Aylward, who led an international mission to China to learn more about the virus and the country’s response, said the evidence did not suggest that we only saw the tip of the iceberg. If these tests are confirmed, it could mean that current estimates of a mortality rate of around 1% are correct. This would make Covid-19 about 10 times more deadly than the seasonal flu, which is expected to kill between 290,000 and 650,000 people a year worldwide.