Scientists from the United States found out that three months after vaccination with Pfizer and Moderna, humoral – associated with antibodies – the immune response to COVID-19 decreases. The article of researchers has been published in the journal Scientific Reports.
Scientists from the North-West University tested blood samples of 27 adults – 13 with a positive test for coronavirus and 14 healthy. The study participants donated blood three times: for the first time after two or three weeks after the first dose of the vaccine, in the second one after the same period after the second, and in the third one two months after it. Researchers evaluated the level of antibodies in the blood and how efficiently over time they block the binding of the protein protein of the coronavirus with ACE2 receptors – the main mechanism of the penetration of SARS-COV-2 into the cell.
The level of production of antibodies in the blood of participants in three months has noticeably decreased. The average level of suppression of antibodies three weeks after the second dose was 98 percent, but after three months it decreased by 20 percent. Humoral immune response for those who have surpassed COVID-19, was expected above. However, it was found that those who suffered a sickness asymptomatic, it was comparable to those of people with a negative test on COVID-19.
Humoral immune response to new strains of coronavirus was lower – three weeks after the second dose of the vaccine, the level of blocking of the pelemaker protein for the “gamma” -Stamma was 70 percent, and for “beta” -stamma – 67. After three months, these were shown decreased by 31 and by 27.5 percent, respectively.