A new coronavirus variant, known as B.1.621, and first detected in Colombia, has shown signs of evading the immune response triggered by either COVID-19 vaccines or previous infection.
According to Reuters, Public Health England (PHE) says the variant "is under investigation" but is not yet a "variant of concern", a designation that can trigger strong policy responses.
"There is preliminary laboratory evidence to suggest that vaccination and previous infection may be less effective at preventing infection with (B.1.621)," it said. There have been 37 confirmed cases of the variant in England.
PHE scientists also warn of early signs that people already vaccinated against COVID-19 could still transmit the Delta variant of the virus as easily as those who have not.
These findings echo those from the US Centers for Disease Control and Prevention (CDC), which recently raised concerns that vaccinated people infected with Delta could, unlike with other variants, readily transmit it.
The highly infectious Delta variant has become the dominant coronavirus type globally, sustaining a pandemic that has already killed more than 4.4 million people, including more than 130,000 in Britain. Vaccines have been shown to provide good protection against severe disease and death from Delta, especially with two doses, but there is less data on whether vaccinated people can still transmit it to others.
“Some initial findings … indicate that levels of virus in those who become infected with Delta having already been vaccinated may be similar to levels found in unvaccinated people,"”PHE said, but this is “early exploratory analysis and further targeted studies are needed to confirm whether this is the case”.
Reuters notes that of confirmed Delta cases that had ended up hospitalised since 19 July, 55.1% were unvaccinated, while 34.9% had received two doses of a COVID-19 vaccine.
Nearly 75% of the British population has had two vaccine doses, and PHE said that “as more of the population gets vaccinated, we will see a higher relative percentage of vaccinated people in hospital”.
See more from MedicalBrief archives:
CDC warns: Delta more transmissible than Ebola, as contagious as chickenpox
Delta variant: Not just hyper-contagious but also multiplies more rapidly inside respiratory tract
COVID-19 vaccines highly effective in most people in clinical risk groups — Massive UK study