Natural vs Vaccine Immunity
” On the basis of hemagglutination-inhibiting and complement-fixing antibody responses, 80 per cent of those vaccinated and 3.4 per cent of those who were naturally immune were reinfected.”
” Naturally immune recruits had significantly higher antibody titres (1:160) than the recruits belonging to the vaccinated age group (1:54). However, 23% of the unvaccinated recruits lacked antibodies against rubella.”
” Although the serum IgG antibody responses persisted for at least eight to 12 months (to date) after either form of infection, the antibody activity appeared to be four- to eight-fold higher after natural infection than after immunization.”
” Natural infection with wild virus was shown to induce more vigorous immune responses than did either vaccine: antibody titers were higher, decreases were smaller, and none fell to <1:8 (HAI) or <1:4 (NT). “