Professor Christine Carrington believes that while there’s still a lot of uncertainty around the highly transmissible Brazilian P1 variant of the Covid-19 virus, getting vaccinated with the AstraZeneca vaccine can provide sufficient protection against it.
Carrington, who is a Professor of Molecular Genetics and Virology at the University of the West Indies, said with the use of genome sequencing on Monday, the presence of P1 was detected in a local sample received from the Ministry of Health via the Caribbean Public Health Agency (CARPHA).
Speaking at Wednesday’s virtual Covid-19 press conference, Carrington gave a scientific explanation to the genesis of vaccine variants and the origin of the P1 variant.
“A virus with one or more new mutations is sometimes referred as a variant of the original virus. Now the vast majority of mutations have little or no effect on a virus’ ability to cause infection or disease but occasionally you do get mutations that arise that affect the virus’ properties.
“For example, a mutation might cause a virus to spread more quickly or less quickly, or it might cause the virus to cause more severe disease or less severe disease. Or you can get mutations that influence the way the virus interact with the immune system.”
She said over the past year, as SARS-CoV-2 (Covid-19) mutations have continued to accumulate, they begun to see the emergence of more and more variants with new properties, some of which are of concern.
She noted that those mutations led to the P1, the B.1.351 or South African variant, and the variant first detected in the UK, B.1.1.7, now known as the three major variants of concern.
“The main concern about P1, 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."
Noting that the P1 variant has 11 mutations in the spike protein region, 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.
“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 vaccine 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,” Carrington said.
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.
“So, how do we prevent this P1 variant from spreading? Exactly as we would prevent any other SARS-CoV-2 lineage or variant. All the other ones that are in circulation, the answer is the same.
“So, wear your mask properly and consistently. Keep your distance from others. Avoid mass gatherings. Practice hand hygiene, and get vaccinated,” Carrington said.