With the highly transmissible Brazilian P1 variant of the Covid-19 virus now present in TT via one local sample, Professor of Molecular Genetics and Virology at the University of the West Indies, Christine Carrington is assuring citizens that the AstraZeneca vaccine can provide adequate protection.
Speaking at today’s virtual Covid-19 press conference, Carrington stated that over the past year, Covid-19 mutations have continued to accumulate, and they have begun to see the emergence of more and more variants with new properties, some of which are of concern.
She said “The main concern about P1 (the Brazilian variant), and also some of the other variants, is that they contain a large number of mutations including mutations in a part of the virus called the spike protein. And that spike protein is a major target for the protective immune response, and it’s also the protein around which Covid-19 vaccines were designed.”
The P1 variant has 11 mutations in the spike protein region and Carrington said laboratory tests have shown that because of these mutations in the spike protein, the P1 variant is a little less neutralised by antibodies produced in response to infection with other non-P1 variants, making it possible for people to be re-infected with this variant, if they were infected with another lineage of the virus before.
“However, very importantly, this resistance to antibody neutralisation is not as great as in B.1.351, the variant first identified in South Africa.
“Also, in terms of vaccine efficacy, while there is evidence that some vaccines may be less effective against P1, a recent scientific article that is yet to be peer reviewed, showed good evidence that antibodies from people who had received the Oxford-AstraZeneca vaccine and also those who received the mRNA vaccine, the antibodies in their sera were able to effectively neutralise P1.
Carrington said “So on the basis of this, it is expected that those vaccines will offer sufficient protection against P1. And it’s also important to remember even in cases where there is reduced vaccine efficacy against a particular variant, the vaccines still work well enough to protect against severe disease, hospitalisation and death. So even where the P1 variant is present or the other variants are detected, it is still worth getting vaccinated.”
She said there is evidence to support P1 being a bit more transmissible than other variants but the extent of the difference and whether it is an inherent property of the virus, meaning you will see the same degree of transmission in other countries as seen in Brazil, still needs to be confirmed.
Carrington also noted that the impact of P1 on disease severity or the duration of an infection, is not clear yet.