Corona: This is how vaccines are adapted to Omikron - experts classify combined products as promising
Created: 06/29/2022, 16:46
By: Judith Brown
So far there is no corona vaccine adapted to Omikron.
Manufacturers are working on its development, following a 5-step plan.
After two years of the pandemic, experts, politicians and scientists are still dealing with the
corona
virus.
They are constantly faced with new challenges.
Because
SARS-CoV-2 is constantly changing
.
The omicron subtype BA.5 is currently responsible for increasing case numbers
and
is not only the
dominant variant
in Germany .
Vaccination
is still considered a
proven
method in the fight against the corona virus
.
There are now various
vaccines
on the market that are used to prevent the spread of the virus.
In order to guarantee vaccination protection, the manufacturers are adapting their already approved vaccines to the new corona variants.
To do this, they must
follow
a 5-step plan specified by the European Medicines Agency (EMA) .
Corona: This is how vaccines are adapted to Omicron
Vaccine manufacturers are currently working on adapting the corona vaccine to the omicron variant.
Health Minister Karl Lauterbach (55, SPD) does not expect approval until autumn 2022.
© Bihlmayerfotografie/IMAGO
Vaccine
manufacturers such as
BioNTech and Pfizer or Moderna
have already developed approved vaccines against the coronavirus.
For the
further development of the vaccines
, the companies adapt their vaccines to the new variants in five steps planned by the EMA.
In individual cases, however, the EMA can also decide to deviate from the guidelines they have specified.
Step 1
: First, the already approved vaccine is adapted to the new variant in the laboratory.
In the case of the
mRNA and vector virus vaccines
, an exchange takes place: the RNA or DNA section, which represents either the entire construction manual or just a piece of the
spike protein
, is removed and replaced with a corresponding section for the spike protein of the new variant replaced.
Step 2
: Following the adjustment, a
technical quality
check is carried out .
The vaccine is examined for
the concentration of the ingredients
,
stability
and
purity
.
However, its effectiveness or compatibility with animals or cell cultures has not been tested.
Step 3
: In the next step, the adapted vaccine is compared with the original vaccine in
two parallel clinical studies
on volunteer study participants.
One of the studies is for initial vaccinations, the other for booster vaccinations for refresher purposes.
The formation of antibodies
is then measured in the laboratory
.
In order to render the new virus variant harmless, sufficient antibodies must reliably be formed.
It is crucial that the adapted vaccine performs better than the original one.
For this test, however, the participants do not have to be infected with the virus first.
Step 4
: The vaccine must finally be
approved by the EU Commission
.
To do this, the manufacturer applies to the EMA for approval of the adapted vaccine, known as the
type II variation
, which can approve it after prioritized testing.
According to the EMA, there is a list of changes that are considered Type II changes.
"In addition, any other variation that may have a significant impact on the quality, safety, or efficacy of the drug must be submitted as a Type II variation," the website says.
Step 5
: If the vaccine is approved, the manufacturer and its production partners convert all or part of the
large-scale production
of the vaccine to the vaccine adapted to the variant.
Companies that produce mRNA or vector virus vaccines have it easy here, as little changes in the process.
Manufacturers have been working on adapted vaccines for the past year
Manufacturers have been developing adapted vaccines for the past year.
For example, Biontech and Pfizer have been working on new versions of their mRNA vaccine since November 2021.
A
monovalent vaccine
should then only protect against omicron.
However, there should also be a
combination vaccine
that
carries mRNA for the spike protein of the Wuhan strain and at the same time the omicron variant
.
Since January, the effectiveness and tolerability of both vaccines have been tested and compared in clinical studies.
Although Biontech and Pfizer announced their Omicron-adapted vaccine for April or May 2022, the process is still ongoing and the vaccine is not yet available.
"mRNA can indeed be adapted very quickly to new variants," explained Dr.
Rolf Hömke from the Association of Research-Based Drug Manufacturers (vfa) in an interview with "Deutschlandfunk" in April 2022. Regulatory authorities, however, had the idea of not only developing vaccines against a specific variant, but also bivalent vaccines that contain components for several variants.
This vaccine should then protect both against, for example, Omicron and against other variants.
Expert considers the development of combination vaccines to be promising
Since the two vaccine manufacturers Moderna and Biontech and Pfizer are currently working on two vaccines in order to compare them with each other, the process of developing the adapted vaccine is taking longer than expected.
But apparently it's worth it: "It has been observed in various places: when different but similar
antigens
are offered to the
immune system
, the
immune reaction
is a bit broader and not fixated on the fact that exactly the right pathogen has to come," says Hömke.
Therefore, the strategy of developing bivalent vaccines that can be used against several variants is promising.
(
jbr
)