With the advent of more infectious new strains and / or mutations of the SARS-CoV-2 virus, Scientists around the world are competing against time to find out how they affect approved vaccines for emergency use against COVID-19..
In this context, New study of new corona virus strains from the UK and South Africa predicts current immunizations Some monoclonal antibodies may be less effective in neutralizing these variants. And brand new versions threaten to overhaul the overhaul.
The Research Published in the prestigious science journal Natural On March 8, January 26, after a pre-print in biroxie, it was reviewed.
“The study’s predictions are now confirmed with the results of the first report of the Novavox vaccine,” explained David Ho, the study’s lead author and microbiologist. The developer of one of the approved vaccines against COVID-19 recently reported it The vaccine was nearly 90% effective in the company’s UK trial, but only 49.4% in its South African trial, Most of the COVID-19 cases are caused by variant B.1.351.
“Our research and data from the new clinical trial show that the virus is moving in the direction of escaping our current vaccines and treatments that have been activated against the virus spike,” said Ho, director of the Aaron Diamond AIDS Research Center.
“If the widespread spread of the virus continues and more significant mutations accumulate, we may be doomed to continue to grow SARS-CoV-2., As we have done for a long time with the influenza virus, ”the researcher added. He warned, “For such surveys we must stop the spread of the virus as soon as possible, redouble our mitigation measures and expedite the start of vaccination.”
After vaccination, the immune system responds and produces antibodies that can neutralize the virus.
Ho and his team were able to observe that antibodies in blood samples taken from those vaccinated with the Moderna or Pfizer vaccine were less effective in neutralizing both types B.1.1.7, and P1.351, which were released in the UK last September. It emerged from South Africa in late 2020. Against the UK variant, neutralization was roughly halved, but against the South African variant, neutralization was reduced by 6.5 to 8.5 times.
However, Ho was rescued: “The large “cushion” of residual neutralizing antibody activity is unlikely to result in approximately twice the loss of neutralizing activity against the UK variant. We see this reflected in the NovaVox results, where the vaccine was 85.6% effective against the UK variant ”.
The study data on the loss of neutral function against the South African variant are of great concern. “Neutralizing the process against South African diversity is commendable, and now based on the NovaVox results, we see it reducing security efficiency,” Ho warned.
The new report does not examine the most recent variation found in the Brazilian manas (p.1.1.28), but the researchers team believes that the South American national variation should behave in the same way, given similar spike mutations between the Brazilian and South African varieties. Just like the South African variant.
“We need to stop copying the virus, which means starting the vaccine faster and sticking to our mitigation measures, such as concealment and physical distance. Stopping the spread of the virus will lead to more mutations,” Ho said.
They also found that some of the monoclonal antibodies now used to treat COVID patients do not work against the South African variant. Based on the results with plasma from COVID patients previously infected with the infection, the B.1.351 variant from South Africa has the potential to cause relapse.
One of these findings A detailed analysis of the variants reported mutations in two recent SARS-CoV-2 strains compared to other recent studies.. All mutations in the two types of spike protein were examined. Vaccines and monoclonal antibody therapies work by recognizing this SARS-CoV-2 spike.
To do this, the researchers developed the SARS-CoV-2 pseudovirus (a virus that produces the corona virus spike protein but cannot cause infection) with eight mutations found in the UK variant and nine mutations found in the South African variant.
Then Sensitivity of this pseudovirus to monoclonal antibodies developed to treat COVID patients is measured, Uniform serum from patients previously infected and serum from patients vaccinated with the Moderna or Pfizer vaccine.
This study measures the neutralizing activity of 18 different monoclonal antibodies, including antibodies in two products licensed for use in the United States.
Compared with the UK variant, most antibodies were potent, although the neutral activity of the two developing antibodies was moderately weakened.
However, Against the South African variant, the neutral activity of the four antibodies was completely or significantly eliminated. Those antibodies include Pamlanivimab (LY-CoV555, approved for use in the United States) and the approved antibody cocktail (REGN-COV) 58, which was completely inactivated against the South African variant, and Kasirivimab, one of the two antibodies. Less effective in neutralizing the South African variant compared to the parent virus. The second antibody in the cocktail, Imdevimab, retained its neutralizing ability just like the whole cocktail.
“Decisions on the use of this treatment largely depend on the local distribution of the South African and Brazilian varieties.It highlights the importance of virus genetic monitoring and the effective development of next-generation antibody therapies. “
Implications of restructuring
Serum from most patients who recovered from COVID before infection had 11 times less neutralizing activity against the South African variant and 4 times less neutralizing activity against the UK variant.
“The concern here is that restructuring is more likely if these species are confronted, especially in South Africa.The microbiologist concluded.
These findings were analyzed by the Irving Medical Center at Columbia University in the United States, and suggest that vaccines and monoclonal antibody therapies provide less neutralizing activity against SARS-CoV-2 strains in the United Kingdom and South Africa.