4/12—South African variant may evade protection from Pfizer vaccine
South African variant may evade protection from Pfizer vaccine, Israeli study says
[Media report.] The study, released ahead of peer review on the medRxiv website on Friday, compared almost 400 people who had tested positive for COVID-19, 14 days or more after they received one or two doses of the vaccine, against the same number of unvaccinated patients with the disease. It matched age and gender, among other characteristics. The South African variant, B.1.351, was found to make up about 1% of all the COVID-19 cases across all the people studied, according to the study by Tel Aviv University and Israel’s largest healthcare provider, Clalit. But among patients who had received two doses of the vaccine, the variant’s prevalence rate was eight times higher than among the unvaccinated - 5.4% versus 0.7%.
Evidence for increased breakthrough rates of SARS-CoV-2 variants of concern in BNT162b2 mRNA vaccinated individuals
[Preprint.] We performed a case-control study that examined whether BNT162b2 vaccinees with documented SARS-CoV-2 infection were more likely to become infected with B.1.1.7 or B.1.351 compared with unvaccinated individuals. Vaccinees infected at least a week after the second dose were disproportionally infected with B.1.351 (odds ratio of 8:1). Those infected between two weeks after the first dose and one week after the second dose, were disproportionally infected by B.1.1.7 (odds ratio of 26:10), suggesting reduced vaccine effectiveness against both VOCs under different dosage/timing conditions.
World leaders call for an international treaty to combat future pandemics.
[Media report. See also EU Council and WHO joint release.] Citing what they call “the biggest challenge to the global community since the 1940s,” the leaders of more than two dozen countries, the European Union and the World Health Organization on Tuesday floated an international treaty to protect the world from pandemics.
SARS-CoV-2 spike variants exhibit differential infectivity and neutralization resistance to convalescent or post-vaccination sera
We monitored neutralization potency of convalescent or Pfizer-BTN162b2 post-vaccination sera against pseudoviruses displaying spike proteins derived from wild-type SARS-CoV-2, or its UK-B.1.1.7 and SA-B.1.351 variants. Compared to convalescent sera, vaccination induces high titers of neutralizing antibodies, which exhibit efficient neutralization potential against pseudovirus carrying wild-type SARS-CoV-2. However, while wild-type and UK-N501Y pseudoviruses were similarly neutralized, those displaying SA-N501Y/K417N/E484K spike mutations moderately resist neutralization. Our study validates the importance of the Pfizer vaccine but raises concerns regarding its efficacy against specific SARS-CoV-2 circulating variants.