The key question in 2021 is whether the new strains of coronavirus will be able to eradicate the vaccine-induced immunity.
This paper on JAMA by John P Moore and Paul A Offit of Cornell and Pennsylvania Universities has been recently published on JAMA.
The protection that vaccines provide against COVID-19 infection is mediated primarily by neutralizing antibodies directed against the S protein of SARS-CoV-2, which the virus uses to invade human cells.
The new strains show variations in the S protein that increase affinity for the ACE2 receptor and create an advantage in virus-to-individual transmission. Theoretically, the effectiveness of vaccines could be influenced by new strains of the virus that can be created when there is evolutionary pressure on the virus by antibodies that restrict but do not eliminate viral replication.
Under such conditions, the virus can find ways to escape the immune response and reproduce efficiently. This is one of the main reasons why the second dose of the vaccine should not be delayed. The evolutionary biology of the virus has been a reality since the early stages of the pandemic.
The first major predominance of a new strain of SARS-CoV-2 was observed in March-April 2020 when the original strain was replaced by the new strain D614G. Although the strain did not escape the immune response from neutralizing antibodies, it was a warning signal. In August 2020 a new strain, B.1.1.7, began to spread in the United Kingdom and was the main strain of COVID-19 cases from November 2020 to January 2021. Fortunately, there are recent indications that Pfizer vaccines / BioNTech and Moderna remain effective against this new executive.
Another important strain that has recently been identified in South Africa and Brazil is B.1.351, which carries mutations that are close to or within the binding region of neutralizing antibodies to protein S and is of particular concern for vaccine efficacy. which remains to be proven.
With all of the above in mind, the authors suggest six steps to take.
-It is essential that SARS-CoV-2 viruses be isolated and fully characterized by all individuals treated for COVID-19 but previously vaccinated against SARS-CoV-2. Only then will new strains with immunity to vaccine-induced immunity be detected.
Secondly, international cooperation is necessary in order to organize and implement both at the national and international level an active system of sequencing of the virus genomes and a monitoring system so that there is tracing of new strains.
-Thirdly, it is advisable to create banks of biological material with sera vaccinated against SARS-CoV-2. In this way, the effectiveness of immunization against new emerging strains can be investigated.
-In addition, it is necessary to reduce the worldwide spread of new strains such as N501Y.V2 and related strains found in Brazil.
Fifth, the design of vaccines based on mRNA technology and adenoids can be adapted to take into account the most important mutations of the new emerging strains.
-Finally, it is worth noting that new strains are not more likely to be transmitted by aerosol compared to previous strains identified in 2020. Therefore, the use of masks, keeping distance and other measures to prevent transmission can prevent spread of the COVID-19 pandemic.
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