Preliminary laboratory studies of the mRNA vaccines by Pfizer and Moderna have shown decreased effectiveness against the double mutant variants discovered in India, the World Health Organization said in a note. This comes on the back of the multilateral agency classifying the mutated virus strain, B.1.617, as a variant of concern, reported Mint.
“Preliminary laboratory studies awaiting peer review suggest a limited reduction in neutralization by antibodies; however, real-world impacts may be limited,” WHO said in its note.
The WHO’s note was primarily describing the characteristics of the B.1.617, which was earlier this week categorized as a “variant of concern”, meaning that the mutant strain and its sublineages (B.1.617.1, B.1.617.2 and B.1.617.3) appear to have higher rates of transmission, including observed rapid increases in prevalence in multiple countries. So far, the strain has been found in 44 countries after first being discovered in Maharashtra in October.
To be sure, while laboratory data suggests these vaccines may see lower effectiveness against the mutant strain, the issue remains inconclusive until studies in real-world settings are conducted.
The global health agency cited three studies, all of which are awaiting peer review, that showed that antibodies generated by the vaccines developed by Pfizer and Moderna had significant reduction in the ability to neutralize the mutant virus and its sublineages.
On the other hand, it cited another non-peer reviewed study that showed that Covaxin was largely effective against the mutant strain of the virus.
One of the studies was jointly conducted by researchers from Emory University School of Medicine in Georgia, US, Stanford University School of Medicine and Vaccine Research Center of US’ National Institute of Allergy and Infectious Diseases. The study conducted tests on blood serum of 24 people who had recovered from covid-19, 15 people vaccinated with Moderna’s vaccine and 10 with Pfizer’s vaccine.
The study concluded that, when compared with the original strain isolated in the US, the variant from India was nearly seven-fold less susceptible to neutralization by blood serum from people who have earlier been infected with covid-19 or those vaccinated with either jabs. However, despite more resistance from the mutant strain, the majority of the sera from infected individuals and all vaccinated individuals were still able to neutralize the variant, the study said.
