Antibodies do not determine immunity any immunologist should know this.
Science and their assumptions,
All that the presence of antibodies in a person means is that the person has come into contact with a particular pathogen, it does not mean that they have immunity.
Antibodies are just ONE part of the immune system response.........maybe antibodies meant something after experiencing a disease as antibody titres were there AS WELL as the rest of the immune response (which isn't measured). But in vaccines antibodies just mean exposure and do NOT mean the immune system went through all it needed to to give lasting immunity or any immunity.

By the way, (vaccine) research has found that IgA antibodies are a much better indication of immunity than IgG antibodies, but when you have gone through the infection naturally (i.e. the antigen has entered through the natural portals of entry), both would be present anyway. When you inject the vaccine ingredients directly into the system, however, you basically bypass the production of IgA, which is another reason why we know immunologically that vaccines are ineffective. Indeed it is the quiet realization of this significant error that is prompting efforts to produce vaccines that are inhaled instead of injected, e.g. the 'flu vaccine (though they will still be pointless and contain harmful ingredients).

It has been theorized by some that vaccines overstimulate the humoral immune response (which incorporates the production of antibodies) at the expense of the other major part of the immune system - the cell-mediated immune response (the production of T cells). I would say that even this is being too kind to vaccines, because it clearly does not even stimulate a normal humoral immune response. The immune system is very complex and with important inter-relationships between its components. The development of immunity requires many processes to occur and complete, requiring the whole team work of all the required immune system components. This simply will not occur other than when the body contracts the infection naturally, and this is only when IT, THE BODY, wants to, not when man wants it to.
http://www.wellwithin1.com/antibodies&immunity.htm