‘Unsure how effective Pfizer vaccine is against South African variant’
"It includes several mutations and Pfizer tested only one mutation – and that is not enough."
By MAAYAN JAFFE-HOFFMANVials with a sticker reading, "COVID-19 / Coronavirus vaccine / Injection only" and a medical syringe are seen in front of a displayed Pfizer logo in this illustration taken October 31, 2020(photo credit: REUTERS/DADO RUVIC/ILLUSTRATION/FILE PHOTO)
It is still unclear how effective the Pfizer coronavirus vaccine is against the South African variant, a top Health Ministry official said Tuesday in a meeting of the Knesset Constitution, Law and Justice Committee.According to Health Ministry Central District Officer Ofra Havkin, “We started examining people who had returned from South Africa and tested positive for coronavirus to see if they had the mutation, as well as people who came in contact with them.”As reported by the Health Ministry, Havkin said that the first group of 12 people screened revealed two South African chains of infections. Another 13 people were sampled over the weekend and the results are forthcoming.“We do not know definitively how much the vaccine is effective against it [the South African mutation]. It will be tested here too, because it includes several mutations. Pfizer tested only one mutation and that is not enough,” Havkin said. “Therefore there is concern and we want as much as possible to stop the South African variant [from spreading].”The Health Ministry first told the public about the cases of the South African mutation on Saturday. On Friday morning, Pfizer reported that its vaccine appeared to work against both of these new variants, according to a laboratory study it conducted.The study, which is not yet peer-reviewed and was conducted by the US company in collaboration with scientists from the University of Texas Medical Branch, indicated that the vaccine was effective in neutralizing the virus with the so-called N501Y mutation of the spike protein.Havkin said that the British variant has spread throughout the United Kingdom and also in Israel.She noted that at the beginning of December, 2% to 3% of people screened carried the British mutation. Now, 50% of those screened for the variant test positive.Variants or mutations are not uncommon in viruses and occur when a genome changes in some way during replication.“Think about if you had to make handwritten copies of the genome – there is a very great likelihood of having a typographical error,” Prof. Jonathan Gershoni from the Shmunis School of Biomedicine and Cancer Research at Tel Aviv University explained. “So whereas in printing books or copying documents, typos are common and understandable, the same is true when replicating a genome. But we call those typos mutations, and the virus bearing those mutations is [called] a mutant or variant.”
With replication, there is a direct relationship between how many copies are being made at a given time and the mutations that are going to be accumulated, he said. If the infection rate is low, then the number of mutations tends to be relatively small. Any time the infection rate is enhanced, so will errors increase.Prof. Nadav Davidovitch, acting chairman of the Association of Public Health Physicians, said that genetic screening for mutations is a common part of Israel’s public health practices.The committee was meeting to review a decision by the Health Ministry to require all Israelis who were in South Africa, Botswana, Zambia or Lesotho to quarantine in a state-run coronavirus hotel within 14 days of their arrival in Israel for between 10 to 14 days.In accordance with the Big Coronavirus Law, the committee was not required to approve the decision because it pertains to fewer than five countries and applies for less than 20 days. The goal of the committee was simply to review it.The decision about people returning from these countries going to hotels is valid through January 17, at which time it will be reevaluated.“The fear of the mutation is clear,” Davidovich said. “The question is whether it is right in terms of public trust to make people isolate straight away in hotels, or to require home isolation but enforce it.”
