(1/4) Vietnam has reported the emergence of a variant which combines elements of the UK (B.1.1.7) & Indian (B.1.617.2) variants. According to the Health Minister it could spread “very fast” in the air.
➡️ straitstimes.com/asia/se-asia/v…
Vietnam is struggling to contain the new variants.
(2/4) A common feature of coronaviruses is their ability to exchange their genetic material (recombination).
This probably happens in all infected people. As the virus reproduces, its copies may exchange genetic material with each other.
Most changes are probably unremarkable.
(3/4) But it’s also possible for people to be infected with different variants at the same time. This is riskier. The more community transmission there is, the more likely this is to occur.
(4/4) Many of these events will have no clinical significance, but there is a risk that more transmissible or virulent variants could emerge.
This is why it’s crucial to suppress transmission of the virus as much as possible until everyone has had the chance to be vaccinated.
Addendum: It looks like the B.1.617.2 variant acquired the Y144 deletion. Given there’s limited community transmission in Vietnam (in relative terms), this probably represents a more simple case of convergent evolution.
Convergent evolution describes the process by which different organisms find the same evolutionary solution to the same problem. Many mutations lead nowhere, but some may give the virus an advantage in reproduction or transmission. We can expect these to pop up around the world.
But co-infection with two (or more) variants is possible and has been previously reported. It’s possible for more serious variants to emerge out of this situation.
Policymakers shouldn’t be trying to manage COVID-19 as if it were seasonal influenza. It’s not and never will be. SARS-CoV-2’s greater transmissibility leads to faster viral evolution. This means waves of disease throughout the year, rather than a single winter COVID season. 🧵
Thanks to vaccination, COVID-19 is far less deadly than it used to be. But a virus doesn’t have to put people in hospital to be disruptive. Leaving aside the issue of long COVID, frequent waves of infection will grind down economic productivity.
Many seem to believe COVID-19 will become seasonal, but why should it? Influenza generally isn’t very transmissible and infects a small number of people each year. There’s plenty of time to design vaccines based on what’s happening in the opposite hemisphere of the globe.
(1/6) Respiratory viruses are much more likely to spread indoors than outdoors, but outdoor super-spreading events can still occur if the conditions are right.
A new study describes a SARS-CoV-2 outbreak affecting 131 people at a night market. 🧵
(2/6) The outbreak happened when a family of 3 people infected with the omicron BA.5.2 variant visited a night market in Zhejiang Province, China, in July 2022. They spent 1 hour and 4 minutes at the market.
(3/6) On the evening of the outbreak, it was warm (27 degrees Centigrade), humid, and there was very little wind.
Most of the market stalls had big umbrellas and it was crowded. The market had a capacity of 5,000 people.
Could future vaccines be administered via a patch? Researchers have developed skin patches containing tiny “microneedles” made of sugar and salt which dissolve on contact with skin, painlessly administering a vaccine in the process. 🧵 asm.org/Articles/2022/…
A key advantage of this technology is that a vaccine patch can induce a special kind of immunity in the skin, known as mucosal immunity, which can prevent infection and transmission. Injectable vaccines may only prevent severe disease.
Skin patch vaccines are also likely to have fewer side effects because of the way they slowly dissolve over minutes to hours.
This slow-release formula is less likely to trigger flu-like symptoms that sometimes follow injectable vaccines.
Imagine if you could rapidly detect COVID-19 in public places by testing the air. Now you can! Researchers have developed a groundbreaking new air monitor that can detect the presence of an infected person in as little as 5 minutes. 🧵 nature.com/articles/s4146…
The compact device, which measures 12 x 10 x 10 inches, has a sensitivity of ~80% and can detect as few as 7 viral RNA copies per cubic metre of air with a resolution of 5 minutes.
The major limitation of the prototype is noise (75-80 dB; similar to heavy traffic), although the researchers are trying to develop a quieter version with low-noise motors and/or sound-proofing.
A representative survey of US adults in mid-2022 found that 7% had long COVID (4-week definition; using questions developed by the UK’s Office for National Statistics).