The UK's drug regulator on Monday said it had approved an updated Moderna vaccine which is supposed to offer better protection against the so-called "Omicron" variant of COVID-19. 

The Medicine and Healthcare products Regulatory Agency (MHRA) said in a statement that it had approved the vaccine for adult booster doses "after it was found to meet the UK regulator's standards of safety, quality and effectiveness." 

As in late 2020, when the UK rushed to become the first country to approve the first COVID vaccine, the MHRA decision came ahead of pending ones expected soon from European regulators, among others. 

Moderna calls the new vaccine "bivalent" because it is designed to stimulate an immune response against two different antigens — both the original COVID variant and the first "Omicron" (or BA.1) variant, which has demonstrated a degree of resistance to existing vaccines. 

The MHRA's top official said the approval did not mean that existing COVID vaccines were no longer useful, however. 

"The first generation of COVID-19 vaccines being used in the UK continue to provide important protection against the disease and save lives," MHRA's Chief Executive June Raine said. "What this bivalent vaccine gives us is a sharpened tool in our armory to help protect us against this disease as the virus continues to evolve." 

US waiting for BA.4 and BA.5 compatibility

Moderna says it expects similar approval from regulators in Europe, Canada, Australia and elsewhere in the coming weeks. 

The Food and Drug Administration (FDA) in the US, however, has said it will seek specific inclusion of the newer Omicron subvariants, BA.4 and BA.5, in any new vaccines to receive domestic approval. 

Although this Moderna vaccine was not designed to counter these, the MHRA also on Monday cited an exploratory analysis suggesting the shot still generates a "good immune response" against the new sub-variants as well. 

The Omicron variant accelerated COVID's spread, proving to be more resistant to vaccines and more readily spread than some other variants. But on the other hand, it also tends to cause more mild symptoms, settling more in the nasal passages than in the lungs. 

Who still needs boosters? 

The UK government said last month that it would start a vaccine booster program in "early autumn" and that renewed doses would be offered to over 50's, individuals in clinical risk groups, frontline workers and care home staff.

Similar debates over how widespread future vaccination drives should be are occupying several other countries including Germany.

With a largely non-lethal virus like COVID, and one which is increasingly becoming endemic, meaning most people have some natural immunity either from past vaccinations or past illness or both, the costs and even the minor risks of universal vaccination might soon be deemed unwarranted. 

Currently, the German STIKO vaccination commission only recommends a second "booster" or fourth vaccine dose to over 70's and at-risk groups. However, Health Minister Karl Lauterbach, a physician who recently suffered a bout of COVID himself, has recommended considering more widespread booster shots. 

msh/wmr (AFP, Reuters)