VARIANT BA.5. In France, the increase in Covid-19 cases is notably due to the presence of a new sub-variant, BA.5, linked to BA.4. Origin, symptoms, contagion, dangerousness… We explain everything to you.
The coronavirus pandemic was not limited to a simple vaccine-stoppable virus. A whole bunch of variants of Covid-19 have appeared over the months, due to the mutation of the initial virus. British, South African, Indian variant, then Alpha, Beta, Delta and, more recently, Omicron… So many names that have evolved over time. And which become even more complex, the Covid-19 having not ceased its mutations. The two latest to date: the BA.4 and BA.5 variants. While, in people’s minds, the Covid pandemic is a thing of the past, the virus continues to circulate in different forms. These last two are regularly mentioned lately. “A progressive replacement of BA.2 has been observed for several weeks with an increase in the detection of BA.5 (41%) and BA.4 (6%)” observed Public Health France at the end of June. But what does this correspond to? What are the symptoms that make it possible to detect them? Is it more contagious or even dangerous? Lighting.
What do the BA.4 and BA.5 variants correspond to?
BA.4, BA.5… Designations worthy of an administrative form to fill out. However, it is indeed one of the many names of the coronavirus disease. In reality, they are sub-variants of the Omicron variant, as the scientists have indicated. A mutation of mutation, therefore. The two letters and the number assigned to them correspond to a specific scientific classification. These two sub-variants have been classified as “variants of interest” by the World Health Organization (WHO).
What is the origin of the BA.4 and BA.5 variants?
If these sub-variants are now very present in France, it is far from France that they find their origin. BA.4 and BA.5 were indeed detected for the first time in South Africa, as early as November. However, there is nothing to confirm that they appeared in this country at that time. It was only thanks to the sequencing carried out by local scientists that they could be isolated in the fall, without providing any insight into their exact origin.
What are the symptoms of the BA.4 and BA.5 variants?
This has been the big question since the appearance of the Covid-19 pandemic: how do you know if you have contracted the virus or not? For the BA.4 and BA.5 sub-variants, several elements can raise suspicion. Asthenia (fatigue) is the symptom that recurs most often according to a report from Public Health France. It should also be noted that the loss of smell and taste can be indicators. Other signs such as cough, fever, headache or runny nose are reported, but only in one out of two cases. It is therefore difficult to rely on it with certainty. On the other hand, an element can put the chip in the ear: that of the duration of these symptoms. They can last about 7 days.
Are the BA.4 and BA.5 variants more contagious?
While the Omicron variant had been presented as dangerous by the authorities given its particularly transmissible nature, the BA.4 and BA.5 sub-variants would also have the ability to be transmitted easily between humans, according to the first analyses, commented on by Public Health France. However, these calculations are based on a small number of cases and there is a high degree of uncertainty. Analyzes are underway to further assess the transmissibility of these subvariants, including investigating whether or not they manage to evade the vaccine.
How dangerous are the BA.4 and BA.5 variants?
For now, scientists lack perspective on these two sub-variants. However, the first elements communicated by Public Health France indicate that no “increase in severity” was observed between the BA.4 and BA.5 sub-variants, compared to the other variants, mainly affecting people at risk. , as for the other variants of Covid.
How effective are vaccines against the BA.4 and BA.5 variants?
While calls to receive a new booster dose of the Covid vaccine have multiplied in recent days, the effectiveness of the vaccines against the BA.4 and BA.5 sub-variants seems however uncertain. Indeed, a study published in The New England Journal of Medicine explains that “BA.4 and BA.5 significantly escape neutralizing antibodies induced by both vaccination and infection.” Antibodies generated by the infection are also lower than with the other variants. “Suggesting that the Omicron variant has continued to evolve with an increased capacity for immune escape,” it adds. New adapted vaccines should thus see the light of day. Pfizer and Moderna are in any case working in this direction.