Omicron: How effective are vaccines to date?

Spread the love

Read Time:4 Minute, 11 Second

The new virus variant Omicron caused a great stir worldwide. The WHO has classified it as “worrying”, it is feared that Omicron is more contagious than Delta. However, it is still unclear which course of the disease it favors and whether the already known vaccines are effective. The fear is that the mutation could have the potential to circumvent the protection of the vaccines currently in use. All major vaccine manufacturers said they immediately began investigating the variant and adapting their vaccines if necessary.

Effectiveness of the vaccines against Omicron
“At the moment, it is being looked at whether the antibodies of test persons who have been vaccinated with the current vaccine still neutralize sufficiently. This was done with the Delta variant as well, and it was shown that the protection provided by the antibodies worked well. With Omicron, however, there are several mutations at the very sensitive spike protein,” says vaccine expert Christina Nicolodi. By midweek, we will know a little more about whether or not it needs adjustment, Nicolodi says. In response to a question from ZDFheute, German virologist Christian Drosten explained that the new variant is probably not capable of completely paralyzing immune protection and that the available vaccines basically continue to protect.

On the adjustments of the COVID Vaccines
If adjustment were necessary, it would happen relatively quickly with mRNA vaccines. “I estimate it takes about three months before the vaccine can be used. To do this, the mRNA sequence is exchanged so that it fits the omicron variant exactly. Then quality tests and studies on safety and immune response follow. Approval is handled very quickly because it would not be a completely new vaccine, but a modification of an already approved one,” Nicolodi points out. This process is similar to the annual adjustment of the flu vaccine, he said. With the mRNA vaccines from Biontech/Pfizer and Moderna, the adjustment is easier than with vaccines based on modified viruses, such as that from AstraZeneca or Johnson & Johnson. This tends to be more prone to errors and more time-consuming.

All vaccine manufacturers are analyzing the new variant by computer as well as in the laboratory. Moderna announced “three lines of defense”: work on an Omicron-specific booster vaccine, a higher-dose booster of Moderna’s vaccine – known as Spikevax – and booster candidates designed to detect mutations like the current Omikron variant. Within 60 to 90 days, the company would be able to move new production candidates into clinical trials, it said. In a BBC interview, Moderna CEO Paul Burton even spoke of an adapted vaccine “being able to be manufactured on a large scale” as early as early 2022. “This is a dangerous-looking virus,” Burton said. “But I think we have a lot of tools in our arsenal now to fight it, so I’m optimistic,” Burton said.

Biontech/Pfizer also made preparations months ago to rapidly develop a modified vaccine variant, the company announced. Within six weeks, the vaccine could be adapted to variants and initial batches shipped within 100 days, he said. Neither mRNA vaccine maker would yet commit to whether a modification is necessary. They expect clarity in “two” (Biontech) or “a few weeks” (Moderna) at the latest. Pharmaceutical companies AstraZeneca and Johnson & Johnson also started analyses. AstraZeneca began testing in Botswana and Swaziland to examine how well the vaccine protects against the new variant.

Novavax, a U.S. biotech company whose protein-based vaccine has not been approved, also says it has started work on a modification targeting the Omikron variant. The vaccine has so far been approved only in the Philippines. Development and approval have been delayed by production problems. In general, protein-based vaccines are more time-consuming, which is also challenging in terms of responding to new variants.

Should we wait for new vaccines before booster or first vaccination?
No – numerous experts agree. “All people who get vaccinated don’t start from scratch when they are infected with a new variant,” said Lothar Wieler, president of the Robert Koch Institute (RKI) in Berlin, for example. They would have in any case already a certain vaccination protection. Christina Nicolodi also shares this view. “The delta variant is still predominant and the current vaccines work well. We need to take pressure off the healthcare system, get the ICUs free, and break the chains of infection. A missing booster can already lead to disease, so there should be no waiting at all,” Nicolodi stressed.

Molecular biologist Martin Moder advised on Twitter not to wait. “In the spike protein there are effective and less effective antibody binding sites. Many of the particularly effective ones have changed and will probably no longer be recognized. But: even less effective ones can do a lot if antibody levels are high enough. I would be extremely surprised if boosted patients had no advantage in terms of severe progression,” Moder said. In addition, the T cells, which target different spike protein sites than the antibodies, would also protect.