Doctors have warned that a new strain of Covid can re-infect people just weeks after they recovered from the virus. Concerns are growing over the BA.5 variant, which is the dominant strain in the US and in other places across the world.
It has long been the case that people who catch Covid-19 then have a level of immunity in the weeks afterwards, the Mirror reports. But doctors from across the world are seeing a different picture with BA.5 as people test positive shortly after recovering from the virus.
Andrew Roberston, chief health officer in Western Australia, told News.com.au: “What we are seeing is an increasing number of people who have been infected with BA.2 and then becoming infected after four weeks.
“So maybe six to eight weeks they are developing a second infection, and that’s almost certainly BA.4 or BA.5.”
Immunology professor Danny Altmann, author of a recent paper on the strain wrote in the Guardian how Omicron infections were a “poor booster” of immunities to other Omicron infections.
He added: “Most people – even when triple-vaccinated – had 20 times less neutralising antibody response against Omicron than against the initial ‘Wuhan’ strain. Omicron infection was a poor booster of immunity to further Omicron infections”.
“It is a kind of stealth virus that gets in under the radar, even having had Omicron, we’re not well protected from further infections.”
Covid-19 infections in the UK have fallen to their lowest level for two months, in fresh evidence the current wave of the virus is receding, figures released last week showed. The number of patients in hospital with Covid-19 is also continuing to drop, though health experts warned infections are likely to rise again in the autumn and winter.
A new booster jab will be offered to everyone in the UK aged 50 and over from next month, as well as those with underlying health conditions, to increase protection ahead of future waves.
A total of 1.7 million people in private households are estimated to have had Covid-19 in the week to August 8, according to the Office for National Statistics (ONS). This is a drop of 34% from the previous estimate of 2.6 million for the week ending July 26.
Sarah Crofts, head of analytical outputs for the ONS Covid-19 infection survey, said: “Infections have continued to fall across much of the UK to levels last seen in mid-June. Our latest data show these decreases are among nearly all ages in England, with the lowest levels seen among children.
“We will continue to monitor the data closely to understand the impact of the summer holidays.”
The current wave has been driven by the Omicron BA.4 and BA.5 subvariants of the virus and saw weekly infections climb as high as 3.8 million in early July. This was not as steep as the record 4.9 million infections at the peak of the Omicron BA.2 wave in late March, however.
