According to a study published Tuesday in the journal Science Immunology, immunity to CoVid-19 lasts at least 8 months. Australian researchers analyzed blood samples taken from 25 SARS-CoV-2 positive patients. These samples were compared to a healthy control group. The researchers then introduced pieces of the virus to see how the blood reacted. In the immune system, it is the T cells and memory B cells – which are part of the white blood cells – that provide long-lasting immune memory. This study shows that even 8 months after a first infection, memory B lymphocytes remember the virus and quickly produce protective antibodies. In addition, the researchers show that these cells recognized one of the two components of SARS-CoV-2: the spike and core proteins. It is still too early to say how long specific immunity can last, but these results offer real hope for long-term vaccine protection.
SARS-Cov-2: the South African variant detected in England
England has confirmed having identified two cases of SARS-CoV-2 variant linked to South Africa, because the other variant that worries is the one discovered in South Africa. Last week, the country’s health minister said the strain was more contagious and also affected young people. Yesterday, the British Minister announced that two cases of this variant have been identified in England, and that it would be more contagious than the other English variant which is already worrying. Is it a statistical effect? For the moment, this variant is still being analyzed. Again, many experts believe that these mutations will not stop vaccines from working. Stricter measures will be taken tomorrow in the UK.
A probiotic intestinal bacteria to fight obesity?
A study published in eBioMedicine describes the discovery of an intestinal microbiota that could help fight obesity, one of the most common chronic diseases in the world. The treatments are limited and ineffective. These Irish researchers have discovered a new strain of bifidobacterium longum with probiotic effects. It was named APC 1472. This strain has been tested in mice, then in overweight and healthy people. Researchers have observed significant beneficial effects on their metabolism. It would help reduce their fasting blood sugar and normalize the levels that stimulate hunger and stress: ghrelin and cortisol. Here is more proof of the close links between microbiome, metabolic diseases and mental health.
Free violence among octopuses?
Finally, according to a study published in the journal Ecology, octopus were caught hitting fish. Free violence among cephalopods? Perhaps. A Portuguese team analyzed videos of octopuses hitting fish with their tentacles, like slaps, which occur in a particular context: when hunting. We know that octopus and certain species of fish work together to hunt prey together. The octopus can therefore slap a fish for practical reasons: to retrieve prey. However, the videos also show octopuses randomly hitting the fish for no apparent reason. We definitely have a lot to learn from the complexity of inter-species relationships, and from the intelligence of the octopus.
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