Waiting for the Omicron Booster: “Doesn’t change the game”?

If the Federal Health Minister Karl Lauterbach gets his way, people over the age of 60 should receive the recommended fourth corona vaccination as soon as possible. “Waiting for adapted vaccines is too long and too risky.” Preparations for this have been in full swing for months. The Omikron-adapted vaccine should hit the market in spring, as existing Covid-19 vaccines are much less effective against this highly contagious variant. It’s fall and the federal government has high hopes for a new refresh campaign. However, many experts warn that elderly and vulnerable people in particular should not wait for new legal highs. Especially since some scientists say they shouldn’t change the game we’re counting on.

“Since the population is already largely immunized by vaccination or infection with more original strains of the virus, the addition of certain omicron variants in downstream boosting applications is unlikely to have as much impact as desired on pandemic control.” Sebastian Ulbert, head of the Department of Vaccines and Infection Models at the Institute of Cell Therapy and Immunology Fraunhofer in Leipzig. In Berlin, however, they want to be prepared for any eventuality: the Ministry of Health assumes that a vaccine will be available in the fall that is adapted to the sub-variant BA.1 of omicron and against the sub-variant BA.5. The BA.1 variant caused a huge spike in infection last winter, but BA.5 has almost completely supplanted the other variants in Germany.

Criticism of the government’s plans comes from the opposition: “Minister Lauterbach continues to buy without taking into account the costs, although the country is facing an economic crisis. Massive surplus of vaccines must already be discarded as demand is minimal and the minister’s vaccination campaign has been going on for months, ”says CDU health expert Tino Sorge. The European Medicines Agency EMA recently pointed out that no one is able to say which crown variant is dominant in the fall.

In their view, BA.5-aligned vaccines for planned fall vaccination campaigns may be ready too late. In this regard, EMA recently pointed to the preference for vaccines adapted by Moderna, BioNTech and Pfizer over the BA.1 variant, which they have been working on since the end of 2021 and of which significant volumes have now been completed. Because while existing vaccines still provide good protection against hospitalization and death, their effectiveness has declined as the virus evolved and new variants emerged.

Bilavente vaccines are coming

Preliminary data showed that booster vaccination with adapted vaccines elicited a stronger immune response than existing vaccines. They also performed well against the BA.4 and BA.5 variants – albeit to a lesser extent than against BA.1. The US Food and Drug Administration (FDA) has already advocated adapted vaccines to combat BA.4 and BA.5, which together dominate the infection process in the US, and no longer expect any new clinical trials to do so. Overall, regulators have signaled their preference for bivalent vaccines, i.e. vaccines that target the original Wuhan virus variant in addition to Omicron. The combination is expected to help increase resistance to the new variants while maintaining the primary immune response.

Moderna relies on two bivalent boosters for fall: In addition to a candidate who has already been tested in a large clinical trial – a combination of its original Spikevax vaccine and one against BA.1. targeted vaccine – also for a booster dose, which in addition to Spikevax is directed against BA.4 / 5. Biontech and Pfizer are also gearing up to convert their production to BA.4 and BA.5. Partners expect significant quantities to be available by early October. Companies completed the marketing authorization application for their BA.1-adapted bivalent vaccine candidate on Tuesday at the EMA.

WHO: “Get the second amp now”

But the World Health Organization (WHO) also advises people over 60 not to wait until fall. Because nearly three million new cases of Covid were reported in Europe last week, almost half of all new cases worldwide. During the same period, the number of hospitalizations doubled. “Time is running out. Immunity is weakening, we have the BA.5 sub-option, which has a big advantage in transmission, ”WHO Regional Director Hans Kluge told Reuters. “Get your second amp now.” If an adapted vaccine came out in the fall, it could be given three to six months after the last immunization. In Germany, only 61.8 percent of people received a booster vaccination, 7.6 percent received a second booster dose. A good 76 percent are primary immunized. The EU health authorities are now recommending a second crown booster vaccination “as soon as possible” to all over the age of 60.

Immunologist Leif Erik Sander of Charite recently pointed out in the NDR Corona podcast that the long-term goal must not be to further vaccinate the general public. So far, however, there is no solution to this problem, even with new afterburners. “The vaccines adapted to the BA.1 variant will have a small added benefit, but I don’t think it will change the rules of the game,” said Sander.

Vaccine expert Ulbert criticizes the idea that the booster only needs to be adapted to circulating variants in order to optimally protect the population is understandable but also somewhat naive. “The immune system doesn’t work that way. The population is having massive primary immunization against the primary virus, be it through vaccination and / or infection, and this also dominates the booster response. ” It is also a natural property of the immune system to be able to expand its repertoire of immune responses to future potential variants of the same pathogen. “In this respect, the selection of the omicron sub-option is likely to be less important than the primary immunization and associated protection against major disease.”

Immunologist Andreas Radbruch, member of the Leopoldin Academy of Sciences and Scientific Director of the German Center for Rheumatism Research, even assumes that no specific booster vaccination is required for the variants: is effective in protecting us from infection, in order to be protected by BA.5. “He expects the tide of infection to be mitigated and most of them will be vaccinated and healed.” We only need a new vaccine when SARS-CoV-3 appears, which it is as different from SARS-CoV-2 as SARS-CoV-2 is from SARS-CoV (-1). The virus that targets our immune system is entirely new. “

(Reuters)

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