Scientists at Ben-Gurion University of the Negev have examined the effectiveness of the Pfizer vaccine against the original corona virus and against the British and South African strains.
Additional strains bearing different combinations of mutations that appear in the envelope protein of the virus have also been tested.
The study findings suggest that the vaccine is effective against the original corona virus and against the strain carrying the British mutation, but provides less protection against the South African version of the virus, and against variants that combine the British and South African mutations.
The data were collected from people who recovered from COVID19, and others who were vaccinated with the first or second dose of Pfizer vaccine. Blood samples were taken 21 days after the first dose of the vaccine, or about ten days after the second dose.
“Our findings show that the effectiveness of the vaccine against the South African strain is less, although it still exists,” says lead researcher Prof. Ran Tauba of the Department of Microbiology, Immunology and Genetics named after Shraga Segal in the Faculty of Health Sciences at Ben-Gurion University of the Negev.
Prof. Taube and his team also tested the level of antibodies that neutralize the blood of corona recoverers, compared to blood taken from vaccines, and compared the ability of these antibodies to protect against infection in the British strain. The findings indicate that the vaccine provides protection levels 11 times higher than the protection levels observed in patients who recovered and were not vaccinated. Also, relative to recovering patients, the first vaccine dose increased the level of protection against infection in the British strain 6 times, and the second vaccine dose resulted in a further 2-fold increase in the virus’ neutralizing ability.
Along with these encouraging results, the effectiveness of the vaccine against the South African strain is 7 times lower relative to the neutralization of the original strain or the British strain.
The research team included Dr. Alona Kuzmina from Prof. Tauba’s laboratory and other partners from Soroka University Medical Center – Yara Khalaila, Olga Voloshin, Dr. Ayelet Keren-Naus, Dr. Liora Bohm, Dr. Yael Raviv, Prof. Yonath Shemer-Avni and Dr. Eli Rosenberg.
This research is supported by grants from the Ministry of Science and Technology in Israel, the National Science Foundation and a task force for the study of the coronavirus of Ben-Gurion University of the Negev.