I present in the European Hematology Association meeting another presentation regarding the efficacy of the Pfizer vaccine for health workers and octogenarians who have been vaccinated in my center. So, I’m going to present data from more than 250 health workers between the age of 25 and 65, and also 110 healthy, so-called healthy individuals, so patients, individuals who have had no hematological or any other malignancy, that they had no [inaudible] impairment and no autoimmune disorder under treatment...
I present in the European Hematology Association meeting another presentation regarding the efficacy of the Pfizer vaccine for health workers and octogenarians who have been vaccinated in my center. So, I’m going to present data from more than 250 health workers between the age of 25 and 65, and also 110 healthy, so-called healthy individuals, so patients, individuals who have had no hematological or any other malignancy, that they had no [inaudible] impairment and no autoimmune disorder under treatment. So, these are the characteristics of these 110, 12 I think, individuals who are octogenarians. The median age are 85.
In this study, we measured both antibodies against the spike RBD of the SARS-CoV-2 virus, and also neutralizing antibodies against the SARS-CoV-2 virus with FDA approved methodology. We measured them on day one, before the first dose of the vaccine, on day eight, day 22, which is before the second dose of the vaccine, day 36 and day 50, so two and four weeks after the vaccine second dose.
What we’ve seen; first of all, the majority of the health workers at the time of first vaccine had not had any antibody against the virus. Only 9% of them had the neutralizing antibody against the virus, suggesting that these 9% had been in contact with the virus, either they knew it or not.
So, the results of the other 91% is that after eight days almost nothing happened, after the first dose of the vaccine. After three weeks there were around 40 to 50% of the health workers who had neutralizing antibodies more than 50%, which is the clinically significant point. This is what it is described in all the vaccine studies. And after the second dose of the vaccine, two weeks after, so almost all health workers had neutralizing antibodies more than 50%, and the vast majority more than 90%. So, almost 90% of the health workers get neutralizing activity of more than 90% for the virus two weeks after the second dose. And four weeks after the second dose this was continued, although there was a very slow reduction in the number of the antibodies, which is also confirmed by the IgG antibodies against the spike RBD.
Regarding the octogenarians, we’ve seen that they had the same pattern, however at lower neutralizing activity. So, four weeks after the second dose the vast majority had neutralizing antibodies against the virus. However, there were around 10% of the octogenarians, especially males, who had not had very good neutralizing activity, more than 50% I mean, in their blood.
So, the conclusion of this study is that first of all, the majority of health workers managed to have neutralizing antibodies after the second vaccine dose, and especially two weeks after that. Four weeks after that, the majority continues to have very high titers, suggesting that possibly if this reduction in the neutralizing antibody follows what’s happening with the healers of the vaccine, possibly 10 to 12 months after the second vaccine dose the vast majority will continue to have neutralizing antibodies. Regarding the octogenarians, 10% of them will not develop very high titers after the second vaccine dose, so they have to continue to have the measures and everything. And I think another important conclusion is that the second dose of this Pfizer vaccine is totally needed, especially for those who are elderly than 50 years of age.