Two variants of the coronavirus, a South African and a British mutation, may be a lot more contagious than the original virus. The variants originated separately, but also have a few striking similarities.
On Wednesday, the British Health Minister announced that a second coronavirus variant, which may be very contagious, has been found in the United Kingdom. This second variant comes from South Africa. In the United Kingdom, there is now the so-called ‘British variant’ and the ‘South African variant’ that are of great concern. What are the similarities and differences between these two?
Several variants are to be expected
The South African and the British variant are two of the many variants of the coronavirus that we now know. It is not surprising that there are many variants; viruses are constantly changing a bit.
Eric Snijder, professor of molecular virology at the Leiden University Medical Center (LUMC), previously explained to NU.nl that most changes do not affect the properties of the virus. The changes that the South African variant and the British variant have undergone seem to have influenced the characteristics of the virus.
Research on virus spread
Marion Koopmans, professor of virology at Erasmus MC, explains that the South African and the British variants have an important similarity: they seem to spread much faster. This is a strong indication that the two variants are more contagious.
This is not entirely certain, according to Koopmans. Coincidence can also contribute to a variant spreading more quickly. Scientists are therefore now researching the variants in the lab.
Specific mutation match
Another similarity between the British and the South African variant, according to Koopmans, is that they have both undergone a striking number of changes. One specific change is common to the British and South African variants. This change is called N501Y. Previous research in mice found evidence that this change makes the coronavirus more contagious.
However, much is uncertain about the significance of this change. Emma Hodcroft is one of the developers of Nextstrain, an online database that tracks the development of coronavirus variants. She imposes Twitter explains that it is possible that the virus will not become much more contagious with just the change N501Y, but that N501Y in combination with yet another change makes the virus a lot more contagious.
British variant is different from the South African
It is therefore not the case that if the South African variant is found to be extremely contagious, this automatically also applies to the British variant. The British and South African variants differ from each other in many ways and originated separately from each other. Koopmans explains that you will therefore have to research both variants separately.
It is now being investigated whether the corona vaccines are equally effective against both variants. Experts expect that the vaccines will still work and vaccine developer Pfizer has no evidence that their vaccine does not protect against these British and South African variants.
How can coincidence influence the spread of a variant? A calculation example:
- There is a village where 50 people are infected with a virus. 25 people have variant A and 25 people have variant B. A big party is held in the village, but not everyone in the village goes there. By coincidence there are 10 people at the party who are infected with virus variant A and 2 people who are infected with virus variant B.
- It’s busy and anyone infected with one of the two variants infects 3 other people. This means that during the party, 30 people become infected with variant A and 6 with variant B. This drastically changes the relationship between the two virus variants in the village.
- After the party, 30 people joined with variant A, so in total there are now 55 people with this variant. In addition, there are 6 extra people with variant B, which brings the total to 31 people with this variant. As a result, variant A occurs almost twice as often as virus variant B after the party, while the two variants before that occurred about as often.