Citat:
Ursprungligen postat av
sno
Folk har ju haft antikroppar 17 år (!) efter insjuknandet i SARS. Jag tror inte att du heller kan säga något med säkerhet även om du tycks vilja läxa upp andra skribenter här i tråden och dumförklara dem trots att du själv tycks ha klent på fötterna med dina tvärsäkra uttalanden.
Nej, inte alla, och det är ju själva poängen med mitt resonemang. Och jag vill dessutom återigen påpeka att "antikroppar" är en alldeles för luddig definition att använda i den här debatten.
Just i fallet med SARS vill jag minnas att försökspersonerna fortfarande uppvisar en immunrespons, men det gäller som sagt inte "antikroppar" utan helt andra delar av immunförsvaret. Vad gäller immunoglobulin G kan man inte mäta nivåerna hos 50% av försökspersonerna efter tre år. De har försvunnit - precis som jag påpekade att de gör.
Among the cohort, 163 (92.61%) of 176 (χ2 = 200.11, p = 0.000002) were IgG positive, which indicated that most patients who met the WHO case definition were indeed infected with SARS-CoV. As shown in the Table, at ≈7 days after the onset of symptoms, the percentage who were IgG positive was ≈11.80%. This percentage continued to increase, reached 100% at 90 days, and remained largely unchanged up to 200 days. Furthermore, after 1 and 2 years 93.88% and 89.58% of patients, respectively, were IgG positive, which suggests that the immune responses were maintained in >90% of patients for 2 years. However, 3 years later, ≈50% of the convalescent population had no SARS-CoV–specific IgG. The OD changes correlated with the changes to the IgG-positive percentage, although the rate of change varied. Both the OD readings (0.93) and positive percentages peaked at 90–120 days; however, the rate of reduction of the average OD readings was much faster, dropping by 22% (0.73) and 40% (0.54) at 1 and 2 years, respectively, after symptom onset (Figure 1).
Our results provide strong evidence that SARS-CoV antibodies are reduced >3 years after the symptom onset. Because antibodies play an important role in protective immunity against SARS-CoV (15), the findings from this study will have important implications with regard to assessing risk for reinfection among previously exposed populations (e.g., hospital staff) and evaluating the duration of antibody-mediated immunity that any candidate vaccine could provide.
https://wwwnc.cdc.gov/eid/article/13/10/07-0576_article
Hope that helps.