Developing a less reactogenic
whole-cell vaccine might be a workaround, but it hasn't been done yet.
Several countries have transitioned from using mouse brain-derived vaccine to newer, less reactogenic
vaccines with simpler dosing schedules, as recommended by WHO (1).
Our responsibility: Do not become discouraged or lose enthusiasm for aP, but explain to parents that, because aP is less reactogenic
, it produces less protection and is less durable, particularly in school-age children.
Alternative approaches to developing this vaccine included attempts at attenuation of RSV, which generally resulted in vaccine candidates that were either too reactogenic
or too attenuated.
Only one negative reactogenic
side-effect was associated with the vector vaccine, i.
However, full exploitation of OMVs as vaccines is prevented by: i) presence of potentially reactogenic
compounds such as LPS, virulence factors, and toxins, ii) presence of several irrelevant proteins, which dilute immune responses, iii) lack of broadly applicable molecular tools to load OMVs with foreign antigens.
Because of side effects of WCV, such as high rates of fever and local reactions, and variable efficacy of WCVs, a less reactogenic
acellular vaccine (ACV) was developed in the 1980s.
Waning of protective immunity after natural infection or vaccination and shifting from reactogenic
Wc vaccines to safer but less effective Ac vaccines are some reasons for pertussis resurgence (3).
botulinum being spore former, a dedicated facility is required; (ii) yields of toxin production are very low; (iii) the toxoiding process involves large quantities of toxin and thus dangerous; (iv) toxoid proteins are not purified thus other proteins may influence immunogenicity or reactivity of the vaccine; and (v) since the residual levels of formalin are part of the product formulation to prevent reactivation of toxin, the vaccine is reactogenic
In this first direct comparison of an AS03B adjuvanted split virion versus whole virion non-adjuvanted H1N1 vaccine, the adjuvanted vaccine, while more reactogenic
, was more immunogenic and, importantly, achieved high seroconversion rates in children aged less than 3 years.
Finally, DNA vaccines are easy to prepare and are not reactogenic
Lepto vaccines are the most reactogenic
of all the vaccines, even more so than the rabies vaccines.