Reporter |
Editor |Xie Xin
According to a Bloomberg report on July 8, Pfizer plans to seek emergency use authorization in the United States in August for a third booster dose of its COVID-19 vaccine.
Previously, Pfizer released additional data regarding the efficacy of the third-dose booster vaccine, indicating that the booster may take effect 6 to 12 months after the second dose to enhance protection against new variants and provide the highest level of immunity. The neutralizing antibody levels induced by the booster are 5 to 10 times higher than those observed after the initial two-dose regimen.
This decision is also considered to be aimed at combating the increasingly severe spread of the novel coronavirus Delta variant. As the country with the highest global vaccination rate for the Pfizer/BioNTech mRNA COVID-19 vaccine, the Israeli Ministry of Health stated on July 5 local time that, due to the spread of the Delta variant, the effectiveness of the Pfizer/BioNTech mRNA COVID-19 vaccine has decreased by approximately 30%, dropping from 95% in May to 64%.
The Delta variant, first identified in India, is reported to be 50% more transmissible than the Alpha variant first detected in the United Kingdom. The Delta variant has become the dominant strain among new cases in a growing number of countries. In China, the local outbreaks that emerged in Guangzhou and Shenzhen in late May, as well as the recent outbreak in Ruili, Yunnan, have both been confirmed to be caused by Delta variants carrying distinct mutation sites, with genomic sequencing results revealing a high degree of homology. The Delta strain is becoming the predominant circulating variant in many countries, and cases of infection have already been reported in 98 countries and regions.
Israel has the highest COVID-19 vaccination rate globally. According to data from Our World in Data, as of July 5, at least 65.43% of the population had received at least one dose of a COVID-19 vaccine, making it one of the countries with the highest vaccination rates worldwide. However, the spread of the Delta variant has reignited the epidemic in Israel, resulting in breakthrough infections among individuals who received the Pfizer vaccine in January or February. The Israeli Ministry of Health stated that the Delta variant is now virtually dominant in the country, accounting for 90% of newly reported cases over the past two weeks.
Under these circumstances, Pfizer and BioNTech are in discussions with U.S. drug regulatory authorities to finalize clinical trial protocols, with trials expected to commence as early as August. The two companies are the first to develop vaccines targeting the Delta variant.