What You Need to Know About Moderna's New Vaccine For Omicron

Moderna Inc. has just received approval from the UK for a Covid-19 booster shot that targets omicron, the version of the virus that's now the world's most widespread. The snappily-named Spikevax Bivalent Original/Omicron has been given the green light for use in the UK and is expected to be rolled out in other countries soon.

Here's all you need to know about the new booster:

Why is the new Moderna vaccine called bivalent?

The new shot targets two separate strains of Covid-19 - the original version of the virus that emerged in the central Chinese city of Wuhan along with the BA.1 subvariant, the earliest version of omicron. Other versions of omicron, BA.4 and BA.5, are now more prevalent, but the virus is evolving faster than new vaccines can be formulated and tested, and this is the closest match available that has received clearance. Moderna has another shot available that targets the BA.4 and BA.5 subvariants, which has been ordered by the US, but not yet cleared.

How effective is it?

Moderna says the drug triggered a strong immune response against the original virus and BA.1 subvariant. It also generated a good immune response against omicron's latest subvariants BA.4 and BA.5., according to the UK government. However, these are findings from laboratory studies that look at levels of disease-fighting antibodies, which is just a proxy for protection in the real world. There's no solid data yet from human trials showing this booster demonstrates superior protection against omicron infections compared to the existing shots.

Who is currently eligible for the bivalent booster?

The bivalent shot has been approved for use as a booster in adults only. So far, it's only approved in the UK, where it could play a role in the fall booster campaign when people aged over 50 or with weakened immunity will be offered another shot. Still, British health officials said people should take any booster offered to them, as existing shots continue to provide excellent protection against severe disease and death.

Which countries will get Moderna's new shot next?

The drugmaker says it has completed regulatory submissions for the updated shot in Australia, Canada, and the European Union and expects further authorization decisions in the coming weeks. The EU recently switched the remaining doses left on its contract with Moderna to the company's new bivalent shot and inked another deal to buy 15 million more doses. The US has purchased 66 million doses of Moderna's other bivalent candidate that targets BA.4 and BA.5; the country has the option to order up to 234 million more.

How often will you need to get the shot?

It's not clear yet how often boosters - bivalent or otherwise - are needed, but experts see annual top-ups for vulnerable people as plausible because Covid immunity wanes over time and the emergence of new variants is inevitable. It's reasonable to expect that Covid shots could be given on a similar annual schedule like the vaccine against the flu, which also changes constantly.

What isn't clear is whether shots will need continual updating, as the original vaccines produced at the height of the pandemic still provide defense against severe disease and death.

How safe is the omicron-targeting booster?

Moderna says the shot's safety profile is similar its original Covid vaccine.

Are there any other bivalent vaccines on the market?

Pfizer is also developing a bivalent vaccine based on the BA.1 strain and has filed for approval with EU drug regulators. GSK Plc and Sanofi are also trialing a shot that targets parts of the beta variant, an earlier iteration of the coronavirus first detected in South Africa. Chinese developers Sinovac Biotech Ltd. and Sinopharm are also updating their inactivated Covid vaccine with omicron variant. None of these shots have been authorized by regulators.

What other new Covid shots are around the corner?

Some drug companies are trying to combine flu and Covid vaccines into one shot. Scientists are also developing pan-coronavirus vaccines that are hoped to guard against Covid along with other cousins in the coronavirus family, including SARS and MERS. The hope, of course, is to develop a shot that not only prevents illness, but forestalls infection altogether. If achieved, such a tool could potentially eliminate the virus for good.

(Except for the headline, this story has not been edited by NDTV staff and is published from a syndicated feed.)