Dialogue through AP-The new variant of SARS-CoV-2 spread rapidly in the UK, with more than 1,400 cases since September. SARS-CoV-2 is the virus that causes COVID-19. It usually accumulates mutations slowly over time, but this new variant has rapidly accumulated many mutations.
If this new version of the virus seems to be retained, what does that mean? Will this new version of the virus replace the old version? Will it be easier to catch? And, most importantly, are the current vaccines still effective?
This is interesting to me because I am an evolutionary microbiologist who studies the link between the spread of infectious diseases and evolution. In particular, I spent a lot of time considering the impact of vaccines on pathogen evolution and the impact of pathogen evolution on vaccines.
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What new SARS-CoV-2 mutants have appeared?
A new version of SARS-CoV-2 (called the B.1
Eight of these 23 mutations affect the spike protein. This is important because the spike protein allows the virus to enter human cells, and it is a key target of our immune response. It can fight the virus during infection and protect us from disease after being vaccinated with Pfizer and Moderna.
If changes in the spike protein help the virus enter human cells more easily, then the virus can spread from person to person more easily.
These mutations may also change the host’s immune system’s ability to resist viruses, which may reduce the effectiveness of current vaccines.
What is the difference between this new version of SARS-CoV-2?
New virus samples isolated from patients indicate that the relative frequency of this mutation has been increasing over the past three months.
As it implied (but did not prove), the increase in frequency is worrying, indicating that the B.1.1.7 isolate of SARS-CoV-2 is more likely to spread than the original virus. Some people estimate that the transmission capacity of the new virus may be 70% higher than that of the old virus. Although these estimates are consistent with the data, it is still too early to make a clear conclusion.
If this increased transmission can be confirmed, it may be due to mutations in the spike protein that enable it to bind more tightly to the ACE2 receptor, thereby providing a way for the virus to enter human cells.
But this may also be due to any other changes in the virus.
Is it more dangerous? If so, why?
If the new version B.1.1.7 is indeed easier to spread than the old virus, in a sense it will make more people sick, which will be even more dangerous.
However, I do not know that there is sufficient evidence that the severity of the disease caused by the new virus is different compared with the old virus. Although there are so few, but few known cases, it is too early to say.
Can Pfizer and Moderna vaccines still be effective against this new strain?
Both Pfizer and Moderna vaccines work by training our immune system to recognize specific versions of viral spike proteins. The version of the spike protein used in the vaccine is designed to match the old virus, not the B.1.1.7 virus. This means that if this new virus spreads widely, the effectiveness of the vaccine may be lower than expected.
For scientists responsible for developing seasonal flu vaccines, the mismatch between vaccines and viruses is an ongoing challenge. But even if there is a virus-vaccine mismatch, the flu vaccine can reduce the likelihood and severity of the disease.
Therefore, the question is not whether the vaccine is effective, but how effective the vaccine will be. The severity of the mismatch is important, but the only way to determine the impact of this situation is through scientific research. As far as I know, no relevant data has been collected. In other words, it is too early to say whether and how this new variant will affect the overall efficacy of Pfizer and Moderna vaccines.
Should people still get a new mRNA vaccine?
The emergence of the new version B.1.1.7 makes it more important for people to get vaccinated as soon as possible.
If this new version is easier to spread, or the effectiveness of the vaccine is reduced due to a mismatch between the virus and the vaccine, more people need to be vaccinated to achieve herd immunity and control the disease.
Moreover, we now have evidence that the synaptic protein of SARS-CoV-2 can change dramatically in a short period of time, so it is important to control the virus to prevent its further development and completely disrupt vaccination efforts.