Vaccines that are injected into the muscle – i.e., the interior of the body – will only induce IgG and circulating IgA, not secretory IgA. Such antibodies cannot and will not effectively protect the mucous membranes from infection by SARS-CoV-2. Thus, the currently observed “breakthrough infections” among vaccinated individuals merely confirm the fundamental design flaws of the vaccines. Measurements of antibodies in the blood can never yield any information on the true status of immunity against infection of the respiratory tract.