I truly think the new concern is the Beta variant (and Delta Plus, which has the Beta mutation).
I note that the UK govt is in recent talks with AstraZeneca to enhance the Beta protection.
UK is talking to AstraZeneca about beta variant COVID jab
The AZ/Oxford University vaccine and other shots from Pfizer/BioNTech and Moderna are known to have less efficacy against the beta variant – also known as B.1.351 – which is estimated to be around 50% more transmissible than earlier strains.
UK is talking to AstraZeneca about beta variant COVID jab -
The Delta Plus variant contains an additional mutation called K417N on the coronavirus spike, which has been found in the Beta and Gamma variants, first found in South Africa and Brazil respectively (Beta was linked to increased hospitalisation and deaths during South Africa's first wave of infections, while Gamma was estimated to be highly transmissible).
Delta plus India: Scientists say too early to tell risk of Covid-19 variant