Антитела после болезни и возраст

[chuka_lis]

В продолжение к посту  о затухающем иммунитете после прививок. Другое долговременное международное исследование уровней антител  IgG к белкам коронавируса (S, N) в крови после ковида, выявило зависимость  падения уровней антител от возраста переболевших.
Соглано их данным, ковид (легкий и умеренный) приводит к тому, что вырабатывается гуморальный иммунитет,  но у  пожилых (старше 60 лет)- ответ более мощный. Однако, у них же  уровни антител и снижаются довольно быстро, по сравнению с другими возрастными категориями. В среднем, за 125-130 дней (т е полгода), антитела в крови  переболевших спустились ниже уровня определения.
Медленее всего снижались титры у возрастных групп 40-50-60 лет.
Зависимости уровней антител или их снижения со временем, от пола - не обнаружено
Возможно, для пожилых стоит разрабатывать отдельные стратегии бустерного прививания.

We recruited 402 individuals with confirmed SARS-CoV-2 infection (PCR) and mild to moderate COVID-19 symptoms (Table 1). We tested an average of 9.8 blood samples per donor (range: 1-34) that were collected between 18 and 403 days after the suspected date of infection. The first blood sample collected following recovery was labeled as patient baseline. Over 92% (372/402) of individuals mounted detectable IgG immune responses against the SARS-CoV-2 30 spike (S) and nucleocapsid (N) proteins (measured by the YHLO iFlash IgG assay). Individuals in the highest age class (60+) had the fastest rates of IgG decay (slope; iFlash = -0.59 and Architect = -0.79), while individuals in the age groups 40 – 49 and 50 – 59 had the slowest average rate of decay in both assays compared to all other age groups. We did not detect an effect of biological sex on IgG levels or decay rate in our cohort. Although the assays have different targets (anti-S/anti-N vs. anti-N IgG), antibodies to both regions of the virus had comparable decay kinetics with IgG levels falling to below the limit of assay detection after 125.5 days (95% CI 116.8-134.4) for the iFlash assay and132.2 days (95% CI 119.6-144.9) for the Architect assay.
Using long-term (>400d) sequential serum samples from recovered COVID-19 patients, our results demonstrate a rapid decay of IgG levels in all age groups with the fastest decay rates observed in 60+ year-old adults. Collier et al. also reported heterogeneity in immune response participants of different ages following vaccination where older participants had lower antibody levels (quantity) and/or lower antibody affinity (quality) (17).
Although antibody responses against SARS-CoV-2 have been seen to be longer lived following mRNA vaccination compared to natural infection (14), the rapid decay in IgG observed in our study suggests that further longitudinal studies are needed to accurately predict long-term immunity in vaccinated and infected individuals. If anti-S/anti-N IgG titers are a good surrogate for protective immunity against SARS-CoV-2, then vaccine boosters will be required by the second year of post-infection recovery and/or immunization to protect against re-infection. Further, our data suggests the optimal timeline for vaccine booster may depend on the age of the patient, for example by prioritizing groups with more rapid decay of antibodies.