This article is from the source 'bbc' and was first published or seen on . It last changed over 40 days ago and won't be checked again for changes.

You can find the current article at its original source at https://www.bbc.co.uk/news/health-55659820

The article has changed 72 times. There is an RSS feed of changes available.

Version 70 Version 71
BA.4 and BA.5 Omicron: How worried should we be? BA.4 and BA.5 Omicron: How worried should we be?
(8 days later)
Two new fast-spreading subvariants of Omicron are causing fresh surges of Covid around the world.Two new fast-spreading subvariants of Omicron are causing fresh surges of Covid around the world.
BA.4 and BA.5 were first identified in South Africa and may soon become the dominant strains in Europe and the US, health experts say.BA.4 and BA.5 were first identified in South Africa and may soon become the dominant strains in Europe and the US, health experts say.
What exactly are BA.4 and BA.5?What exactly are BA.4 and BA.5?
Ever since it first emerged, Covid has been mutating or shape-shifting. The new genetic versions that keep appearing are called variants.Ever since it first emerged, Covid has been mutating or shape-shifting. The new genetic versions that keep appearing are called variants.
There have been a few major variants already, such as alpha and delta, that have caused massive waves of infection.There have been a few major variants already, such as alpha and delta, that have caused massive waves of infection.
The latest ones experts are concerned about - BA.4 and BA.5 - are very closely related to the Omicron variant behind last winter's wave.The latest ones experts are concerned about - BA.4 and BA.5 - are very closely related to the Omicron variant behind last winter's wave.
They were added to the World Health Organization's monitoring list in March and have also been designated as variants of concern in Europe.They were added to the World Health Organization's monitoring list in March and have also been designated as variants of concern in Europe.
Where are they spreading?Where are they spreading?
They were spotted circulating in South Africa at the beginning of the year and now appear to be spreading much more quickly than other variants.They were spotted circulating in South Africa at the beginning of the year and now appear to be spreading much more quickly than other variants.
Most European countries now have them and they look set to overtake other types of Covid soon. That's already happened in Portugal - BA.5 is now dominant there.Most European countries now have them and they look set to overtake other types of Covid soon. That's already happened in Portugal - BA.5 is now dominant there.
In the US, officials say they are seeing rising numbers of infections caused by the two new subvariants.In the US, officials say they are seeing rising numbers of infections caused by the two new subvariants.
Covid infections in the UK are also showing early signs of a possible rise, driven by BA.4 and BA.5. Covid infections in the UK are also increasing, driven by BA.4 and BA.5.
Australia has reported cases too.Australia has reported cases too.
Will they be harmful?Will they be harmful?
Experts are unsure how hard countries will be hit.Experts are unsure how hard countries will be hit.
BA.4 and BA.5 Omicron are not thought to be any more lethal than other types of Covid.BA.4 and BA.5 Omicron are not thought to be any more lethal than other types of Covid.
Lots of people have built up some immunity from past infections and vaccination, which is helping to make the disease less risky overall.Lots of people have built up some immunity from past infections and vaccination, which is helping to make the disease less risky overall.
But the new subvariants do appear to be spreading more easily.But the new subvariants do appear to be spreading more easily.
This is partly because immunity may be waning, but also because of the mutations the virus has undergone.This is partly because immunity may be waning, but also because of the mutations the virus has undergone.
Many countries have also lifted their Covid restrictions, meaning people are mixing more, which gives the virus more chances to spread.Many countries have also lifted their Covid restrictions, meaning people are mixing more, which gives the virus more chances to spread.
BA.4 and BA.5 appear to be able to infect people even if they've recently had other types of Omicron.BA.4 and BA.5 appear to be able to infect people even if they've recently had other types of Omicron.
A wave of new infections could lead to more hospitalisations and some more deaths.A wave of new infections could lead to more hospitalisations and some more deaths.
How can we protect against them?How can we protect against them?
As with other Covid variants, the risk or serious illness remains highest for people who are elderly, or who have significant underlying health conditions.As with other Covid variants, the risk or serious illness remains highest for people who are elderly, or who have significant underlying health conditions.
Although current vaccines are not a perfect fit, they are still the best line of defence.Although current vaccines are not a perfect fit, they are still the best line of defence.
They have cut the risk of severe illness against the other major Covid variants, including Delta, Alpha, Beta and Gamma.They have cut the risk of severe illness against the other major Covid variants, including Delta, Alpha, Beta and Gamma.
Doctors say it is vital people get the recommended number of doses to gain maximum protection against existing and emerging variants.Doctors say it is vital people get the recommended number of doses to gain maximum protection against existing and emerging variants.
Extra Covid booster in spring for over-75s and high riskExtra Covid booster in spring for over-75s and high risk
How many people have been vaccinated so far?How many people have been vaccinated so far?
How quickly could we get new vaccines against variants?How quickly could we get new vaccines against variants?
Updated versions of vaccines against Covid variants are already being designed and tested.Updated versions of vaccines against Covid variants are already being designed and tested.
Manufacturers could scale up production quickly too, and regulators have already discussed how to fast-track the approval process.Manufacturers could scale up production quickly too, and regulators have already discussed how to fast-track the approval process.
Why do variants occur?Why do variants occur?
Viruses make carbon copies of themselves to reproduce, but they aren't perfect at it. Errors creep in that change the genetic blueprint, resulting in a new version of the virus.Viruses make carbon copies of themselves to reproduce, but they aren't perfect at it. Errors creep in that change the genetic blueprint, resulting in a new version of the virus.
If this gives the virus a survival advantage, the new version will thrive.If this gives the virus a survival advantage, the new version will thrive.
The more chances coronavirus has to make copies of itself in us - the host - the more opportunities there are for mutations to occur.The more chances coronavirus has to make copies of itself in us - the host - the more opportunities there are for mutations to occur.