9th March 2021.
High level of antibodies after the first dose of vaccine
People who had recovered from COVID-19 had a considerably high level of antibodies after the first dose of vaccine, which did not increase after the second shot, so they most probably will not need a second dose, the director of the Hospital for Infectious Diseases in Zagreb, Alemka MarkotiŠ, said on Monday.
Speaking at a regular press conference given by the national COVID-19 response team, MarkotiŠ presented the results of a study conducted by the hospital among its staff. The results have also been requested by the European Medicines Agency.
Women responded better than men
All staff had statistically considerably higher immunoglobulin levels a month after the second dose of vaccine compared with the first dose. Women responded better and had higher levels than men, especially after the second dose. There was a slightly negative correlation with age, as elderly subjects had a weaker response, which was moderate, MarkotiŠ said.
After the second dose, there was a considerable rise in the level of antibodies. None of the staff fell ill after the vaccination, and no differences were established among staff in respect of their job at the hospital, she added.
So far 426 (55.3%) of the staff at the Hospital for Infectious Diseases have received two doses of the Pfizer vaccine. Eight of them developed allergic reactions after the first dose and were not administered a second dose.
Initial serological tests were done on 420 staff three weeks after the administration of the first dose and shortly before the second dose, while second serological tests were performed on 82 staff four weeks after the second dose.
The subjects were 344 women and 89 men. They included 321 health workers and 112 workers in the healthcare system who are not in as close contact with patients as health workers.
Women better responded to the vaccine after the first and second shots. There is a negative correlation between the level of antibodies and age, which was expected given that the immunology system becomes less responsive with ageing, MarkotiŠ said. (hina)