Savior "dead vaccine"?
Studies on Novavax and Valneva make people sit up and take notice
Created: 12/21/2021, 09:39 AM
From: Jonas Raab
With Novavax and Valneva, two new vaccines could soon be approved, which are commonly referred to as "dead vaccines".
This is how they work.
And do they also work?
Munich - On Christmas Day 2020, a 101-year-old woman received the first corona vaccination in Germany.
72.6 percent of the population (as of December 13) have done the same as the home resident from Halberstadt and had themselves vaccinated against Covid at least once - too little, as experts prophesied and confirmed the first winter months.
A considerable part of the German population is still skeptical about the Covid vaccination.
For some, the lateral thinkers, that doesn't seem to change anymore.
With others, the skeptics, it is not uncommon that they miss long-term studies - or that they are waiting for a dead vaccine, such as one known from hepatitis or polio vaccines.
According to a survey by the University of Erfurt, vaccination skeptics rate such preparations as safer.
“Whatever the reason,” Health Minister Karl Lauterbach recently commented on this phenomenon on Twitter.
Novavax and Valneva: Two new vaccines in the starting blocks
With the Covid-19 vaccines "Nuvaxovid" from the US manufacturer Novavax and the vaccine "VLA2001" from the French pharmaceutical company Valneva, two such dead vaccines are about to receive EU approval. Both are currently being tested extensively and are nourishing the hope of a “vaccination boost” for those who have not yet made up their minds - a dead vaccine is only one of the two vaccines, however, and initial studies are scratching the product's image of salvation a little.
What's the difference?
And what are dead vaccines anyway?
According to the current definition, they either consist of inactivated pathogens or pathogen components.
This applies to the French Valneva vaccine as well as to Novavax - and in fact also to mRNA and vector vaccines, because their components cannot multiply either.
There are nevertheless differences;
they lie in the mode of action of the individual vaccines.
That is the difference between mRNA, vector and dead vaccines
mRNA vaccines
(for example Biontech or Moderna) contain gene segments of the SARS-CoV-2 virus in the form of messenger RNA (mRNA for short), which is also known as messenger RNA. Starting from the mRNA, proteins are produced in body cells after inoculation, which then stimulate the immune system to generate specific antibodies against SARS-CoV-2 and a cellular defense against SARS-CoV-2-infected cells, thus generating an immune reaction. Proteins that stimulate an immune response are called antigens.
Vector-based vaccines
(
e.g.
AstraZeneca) consist of viruses that are harmless to humans and that have been genetically modified so that their genome contains the genetic sequence with the blueprint for one or more components of the pathogen (antigen) against which the vaccine is directed . The Covid-19 vector vaccine candidates contain harmless, well-studied carrier viruses whose genome contains a gene that contains the blueprint for the SARS-CoV-2 surface protein, the spike protein.
Inactivated vaccines
do not contain any viruses that can replicate.
They contain killed pathogens or pathogen components that can neither multiply nor trigger a disease.
“The dead vaccine is called dead vaccine because it does not multiply in the body.
That which is in the syringe in it, that alone acts as a kind of vaccine, "explains Martina Sester, professor of immunology at the University of Saarland, opposite
br.de
.
In contrast to the classic inactivated vaccine Valneva, Novavax is a recombinant protein vaccine, as Florian Krammer, Professor of Vaccination Studies, recently made clear on Twitter.
"That's true.
But because so many unvaccinated people only want dead vaccine, for whatever reason, Novavax will soon be available as such, ”Lauterbach replied.
So be it.
In any case, Novavax consists of the spike protein that sits on the surface of the coronavirus and was produced using genetic engineering methods.
"In principle, almost all vaccines nowadays, and also many drugs, are manufactured using genetic engineering or at least the most modern laboratory technology," explains Leif Erik Sander, head of the Infection Immunology and Vaccine Research Research Group at Charité Berlin in
Der Spiegel
.
In contrast to Valneva, Novavax is not a dead vaccine - but they have one thing in common
The main difference between the Covid-19 vaccines is that the inactivated vaccine from Valneva and the protein vaccine from Novavax - in contrast to the vaccines that have already been approved - have to be treated with potentiometers so that they generate a reliable immune response Vaccine expert continues.
Such amplifiers are necessary because the body otherwise produces relatively few antibodies after a dead vaccine injection and the T cell response is also weak.
Novavax is commonly referred to as a dead vaccine, but is actually a "recombinant protein vaccine".
© Sven Simon / imago
Both the inactivated vaccine Valneva and the protein-based vaccine Novavax have shown respectable results in initial studies.
Novavax reduces the risk of symptomatic Covid disease by at least 86 percent.
In contrast to Novavax, Valneva achieved the same results as AstraZeneca during the Delta times.
Novavax and Valneva: Direct comparisons with Biontech, AstraZeneca and Co. are still missing
According to the data known so far, both vaccines are well tolerated, says vaccine expert Sander im
Spiegel
.
"Directly comparable data on basic immunization with mRNA and vector vaccines are still missing." A large-scale comparison of the new vaccines with Biontech, Astra and Co. is currently only available for the booster effect - i.e. use as a third vaccination.
All boosters worked, but the mRNAs cut off the best by far.
Leif Erik Sander
2,900 people with a primary vaccination in Great Britain were given either one of the four approved vaccines or Novavax or Valneva.
Moderna did the best, Valneva the least.
“All the boosters worked, but the mRNAs were by far the best,” summarizes Sander in
Der Spiegel
.
“I would actually have expected the protein vaccine from Novavax to increase antibody titers to a similar extent.
That was not the case in the study, ”says the head of the Infection Immunology and Vaccine Research research group at the Charité in Berlin.
How well do Novavax and Valneva work?
Experts express concern
According to
Spiegel
, experts also assume that inactivated vaccines such as Valneva are inferior to vector and mRNA vaccines in the omicron variant.
The news magazine quotes vaccine expert Florian Krammer: At Omikron, he is more concerned about “the inactivated vaccines” - that is, about Valneva and Novavax, they say.
There is another downer;
it is provided by the above-mentioned survey by the University of Erfurt on willingness to be vaccinated.
"It should not be expected that the majority of the previously unvaccinated people will be vaccinated with a dead vaccine that may be available in the future," it says.
(yo)
