Antibodies increase by 6 to 20 times after second Pfizer dose – Sheba

People who received their second dose of the Pfizer vaccine saw a six to 12 times increase in the amount of antibodies produced to defend against the novel coronavirus, according to preliminary research released Monday by Sheba Medical Center.The results were based on 102 cases of medical personnel vaccinated at the hospital. The results also showed that these people’s antibodies were even higher than those of people who were severely infected with the virus and recovered.“The results of the survey are in-line with Pfizer’s experiment and even better than expected,” said Prof. Gili Regev-Yochay, director of the medical center’s Infectious Disease Epidemiology Unit, in a briefing Monday. “I expect that the survey results of the other employees participating will be similar. There is certainly reason for optimism.”She said that the result of the data is that Israel should see a reduction in the outbreak of the coronavirus across the country as more people receive their second doses.Two people did not develop antibodies, one who is immunocompromised, explained Regev-Yochay. She said there is still no explanation for why the second person did not develop antibodies and the hospital is investigating the matter.So far, some 7,106 employees of Sheba were vaccinated with the first dose – approximately 80% of all staff. Of those, some 4,484 have received their second dose as of January 18. As mentioned, this study only involved 102 cases, but Regev-Yochay said that others were being evaluated.The study is specifically looking at immunoglobulin G (IgG) antibodies, which determine whether a patient has developed immunity. The study does not indicate how long the immunity will last or if a person who has antibodies can still carry the virus and infect others, Regev-Yochay stressed. However, she did say that it is the preliminary understanding on her part that people who have been vaccinated will not shed the virus.

She also noted that while people who were sick and recovered are not yet eligible to receive the Pfizer vaccine in Israel, if further research shows that the vaccine produces improved immunity, it is possible that these people will be inoculated in a second phase, at least with the booster shot. Source