“ So studies showing decreasing natural immunity over time without vaccination supports your statements that natural immunity lasts longer…”
Well, yes, when other studies show immunity after the vaccine waning after 4 months.
“ Effectiveness declined gradually thereafter, with the decline accelerating after the fourth month to reach approximately 20% in months 5 through 7 after the second dose.” (NEJM paper above)
And those studies do show that immunity after infection is durable for 9-12 months in the majority which is what I have stated on this thread. :)
“ The updated evidence summary identified 19 large cohort studies involving over 640,000 previously infected individuals, including six studies with over ten months’ follow-up. Across studies, the risk of SARS-CoV-2 reinfection was consistently found to be low. No study reported an increase in reinfection risk over time. More limited data were identified in relation to the immune response to SARS-CoV-2 infection. The identified studies suggest that immune memory develops in most or all people that have been infected with SARS-CoV-2 and lasts for at least nine months”
“ Here we show that in convalescent individuals who had experienced mild SARS-CoV-2 infections (n = 77), levels of serum anti-SARS-CoV-2 spike protein (S) antibodies declined rapidly in the first 4 months after infection and then more gradually over the following 7 months, remaining detectable at least 11 months after infection.”
“ This in-depth longitudinal study demonstrates that durable immune memory persists in most COVID-19 patients, including those with mild disease, and serves as a framework to define and predict long-lived immunity to SARS-CoV-2 after natural infection.”