Jul 30, 2021 14:00:00

Pfizer announces that 'booster shots' of three vaccinations will increase protection against delta mutants

In principle , the new coronavirus vaccine developed by Pfizer and Moderna is inoculated twice. On July 28, 2021, Pfizer announced the results of a study showing that 'booster shots', in which the company's vaccine is given three times, are effective against the delta mutant strain of the new coronavirus.

Pfizer data suggest third dose of Covid-19 vaccine'strongly' boosts protection against Delta variant --CNN
https://edition.cnn.com/2021/07/28/health/pfizer-third-dose-data-bn/index.html

Delta variant: Israel to give Pfizer Covid booster shots to elderly
https://www.cnbc.com/2021/07/29/delta-variant-israel-to-give-pfizer-covid-booster-shots-to-elderly-.html

In its second quarter 2021 (PDF file) earnings report released on July 28, Pfizer said, 'People aged 18-55 years after the third vaccination will target the delta mutant. Antibodies increased more than 5 times, and in people aged 65-85 years, antibodies increased more than 11 times. '

Of the following, the graph on the left is the result of a booster shot clinical trial targeting 18 to 55 years old (11 subjects) and the right is a graph of 65 to 85 years old (12 subjects). The green graph showing the antibody titer of the non-mutant strain is '310' after the second inoculation for people aged 18 to 55 years, '1547' after the third inoculation, and the blue graph showing the delta mutant strain is '241'. It was confirmed that the number increased from to '1321', and this effect was also seen in people aged 65 to 85 years.

The results of this study are small, with a total of 23 subjects and have not been peer-reviewed, but Pfizer's medical department head, Michael Dorsten, said, 'More than six months have passed since the vaccination was completed and the preventive effect has begun to diminish. It has been suggested that a third dose of vaccination can increase a subject's antibody titer by up to 100-fold at the same time. Data from this preliminary study show that delta mutants are rampant. It's very encouraging inside. '

As of July 2021, US health officials have been cautious about the need for booster shots. 'I don't think people need to be vaccinated with booster shots,' MHLW's medical director Vibeck Mercy told CNN. According to experts, it is unknown how antibody levels are associated with immunity, so simply increasing antibodies does not mean that immunity to the new coronavirus is increased. In addition, the functions of immune systems other than antibodies, such as

B cells and T cells, have not been completely elucidated.

Meanwhile, the Israeli government, which vaccinated early, will provide a third vaccination to people over the age of 60 on July 29, given the spread of delta mutant infections in the country. I decided that. The Israeli Ministry of Health has shown that the effectiveness of the second vaccination is reduced to 39% , while the third vaccination is 88% for hospitalization and 91% for aggravation. It is said that the effectiveness of

'We are continuing discussions with regulators about the third vaccination, and depending on the outcome of the talks, we plan to apply for an emergency use authorization for booster shots as early as August,' Dorsten said at a financial results briefing. I told you.