A new study cautiously suggests that our existing vaccines may be less effective against the South African corona variant.
In the meantime, a new variant of the corona virus has emerged in both Great Britain and South Africa. No one is surprised that the coronavirus is undergoing changes. All viruses evolve. In addition, variants of SARS-CoV-2 have been in circulation since the pandemic began. These are simply the result of a natural process that allows viruses to develop and adapt to their hosts. Yet the South African corona variant may be a different story. Because researchers now cautiously state in a study that this variant may be able to withstand our coveted vaccines.
On the surface of the coronavirus are so-called ‘spikes’: proteins that allow the virus to bind to the ACE2 receptor and penetrate human cells. And now researchers have discovered one mutation in this so-called ‘spike protein’ of the virus in the British variant and two mutations in the virus’s spike protein in the South African variant. These mutations have been associated with higher infectivity, although it does not seem to make people more seriously ill. However, it could mean that the virus spreads faster and that way infects more people. In addition, the mutations can have consequences for how easily you can be re-infected by a variant of the corona virus and for the developed corona vaccines..
When you have contracted the coronavirus, your body produces antibodies to fight the virus. These antibodies ensure that you may remain protected against the virus for several months. The chance of re-infection is therefore smaller during this period. But the South African corona variant now appears to be able to avoid these protective antibodies. “The South African corona variant appears to be able to escape the neutralizing antibody response, largely due to the presence of the E484K and K417N mutations,” explains virologist Julian Tang, associated with the University of Leicester to. This means that the South African variety may have found a way to bypass our immune system, increasing the chance of reinfection.
The mutant worries scientists. “This variant of the SARS-CoV-2 virus may be able to partially evade immune protection or a previous infection,” says virologist Lawrence Young, who is associated with the Warwick Medical School, together. This suggests that people could potentially become infected again with a variant of SARS-CoV-2, even if they have previously had COVID-19. It also shows that we urgently need to investigate whether people can still become infected with this variant after vaccination. ” Indeed, because according to the researchers it could mean that the mutations limit the effect of the corona vaccine. “The mutations mean that in some people this may reduce the efficacy of spike protein-based vaccine-induced antibodies,” said Tang.
How did the researchers reach that conclusion? In the study, the researchers analyzed the recovering plasma from previously infected corona patients. They then studied the impact of the specific mutations in the spike protein and how they affect the binding of neutralizing antibodies. The research team then observed a high degree of resistance to the restorative plasma. In almost half of the cases (21 of 44, so 48 percent), the plasma turned out to offer no protection against the new variant. It means that previously infected persons may be more susceptible to reinfection. In addition, as mentioned, it also has implications for the effectiveness of current SARS-CoV-2 vaccines which are all based on the original spike protein.
While that may sound alarming, it does not necessarily have disastrous consequences. Our body also has other ways to get rid of a virus. “Later in the study, the researchers did find significant binding to the South African corona variant via other, non-neutralizing antibodies,” says Tang. “And they can still provide significant protection.” Moreover, we could also look further than just these antibodies. Our body also has T cells, for example. This is a type of white blood cell that specializes in recognizing virus-infected cells. These T cells are thus an essential part of the immune system. In other words, T cells are immune cells and clean up the infection, as it were. Whether the South African corona variant also affects these cells is still unknown.
Battle for the arm
All in all, the researchers are therefore keeping a close eye on things for the time being. “The data is alarming, but it is important to emphasize that these are still laboratory findings,” said Liam Smeeth, professor of clinical epidemiology. “It is very unwise to extrapolate this stage to the clinical effects in humans.” In addition, the study has not yet been peer-reviewed, which means it has not yet been peer-reviewed. Although that will probably not be long. “The research is well done,” says the director of it Rosalind Franklin Institute James Naismith. “It’s not good news, but it’s not entirely unexpected. However, we must not panic. The human immune response in the real world is more than neutralization based on antibodies. ”
Still, the findings do put scientists on edge. Because what exactly is the situation with the British variant of the corona virus? Recent research has also been carried out on this by another research group. The scientists examined whether the Pfizer vaccine also offers protection against this variant. Twenty-one days after the participants received the second dose of the Pfizer vaccine, 16 of them had a little blood drawn. The researchers then considered the antibodies. And the results are encouraging. It seems that the vaccine is just doing its job and also blocks an infection from the mutated British coronavirus.
How the vaccine works
Most of us are familiar with how traditional vaccines work. You are injected with a weakened or dead virus, on which your body produces antibodies against that virus. When you then actually come into contact with that virus, you are protected and you will not become or at least less seriously ill. The vaccine that Pfizer developed works differently. The vaccine – designated BNT162b2 – is a so-called mRNA vaccine. The vaccine does not harbor weakened or dead SARS-CoV-2, but messenger RNA (mRNA): a molecule that contains the genetic instructions for making the characteristic spike proteins found on the outside of the virus. After vaccination, our cells start working with these instructions and produce these spike proteins, after which our body can produce antibodies against them. It is a completely new approach, which is very promising, especially in the case of COVID-19, because mRNA vaccines can be produced much faster than traditional vaccines. It is also easier to scale up and produce large quantities of the vaccines.
Thus, the findings indicate that the Pfizer vaccine should still be optimally effective against the UK variant. Why does the vaccine protect against the British mutant and may be less effective against the South African? “Unlike the South African variety, the British variety has only one mutation (N501Y),” explains Tang. So it remains to be seen whether the Pfizer vaccine will protect against other variants as well, as some mutations are more significant than others. Moreover, there are probably more mutations to come. “The more the virus circulates among people, the more mutations there will be,” says Ayfer Ali, associate professor at the Warwick Business School. “And the more mutations, the greater the chance that the vaccine will not work. However, the fact that the Pfizer vaccine produces antibodies that can neutralize the British variant is reassuring. ”
Vaccination, vaccination, vaccination
Several studies are now needed to properly map the true impact of the South African corona variant. “In the meantime, we just have to keep vaccinating,” Tang emphasizes. “We also have to observe the current lockdown restrictions in order to protect the vulnerable until each of them has been vaccinated.” Naismith also underlines that it is essential to continue the vaccination program. “We need to vaccinate as many people as possible,” he says. “Current vaccines, even if they do not provide complete protection against future hypothetical variants, may still be effective enough to reduce the severity of a possible new infection.”
In short, it seems that a single vaccine is unlikely to end the corona crisis. “However, we will soon be able to develop new, modified vaccines,” said Naismith. “We must not become discouraged; we have the resources to understand and understand the story. However, it will take time and there will always be some setbacks. ”
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