Understanding modern-day vaccines: what you need to know

Abstract

Vaccines are considered to be one of the greatest public health achievements of the last century. Depending on the biology of the infection, the disease to be prevented, and the targeted population, a vaccine may require the induction of different adaptive immune mechanisms to be effective. Understanding the basic concepts of different vaccines is therefore crucial to understand their mode of action, benefits, risks, and their potential real-life impact on protection. This review aims to provide healthcare professionals with background information about the main vaccine designs and concepts of protection in a simplified way to improve their knowledge and understanding, and increase their confidence in the science of vaccination ( Supplementary Material ). KEY MESSAGE Different vaccine designs, each with different advantages and limitations, can be applied for protection against a particular disease. Vaccines may contain live-attenuated pathogens, inactivated pathogens, or only parts of pathogens and may also contain adjuvants to stimulate the immune responses. This review explains the mode of action, benefits, risks and real-life impact of vaccines by highlighting key vaccine concepts. An improved knowledge and understanding of the main vaccine designs and concepts of protection will help support the appropriate use and expectations of vaccines, increase confidence in the science of vaccination, and help reduce vaccine hesitancy.

Liposomes used as a vaccine adjuvant-delivery system: From basics to clinical immunization

“…For example, in recent years, immunization of oral polio vaccines consisting of the live attenuated polioviruses was astonishingly found by gene sequencing to be the cause for several pandemics of polio, due to the reversion of the vaccine strains to the neurovirulent and transmissible state of wild polioviruses [47]. By comparison, the vaccines made of inactivated microorganisms are relatively safe, but they stimulate rather weak and even target-deviated immunoresponses, as a result of both the inactivation process, which may alter the sequence of authentic Ags, and the comprehensive components, which are likely to induce the irrelevant immunoresponses and even trigger unwanted inflammations due to existence of reactogenicity [48].…”

RNA is taking its Toll: Impact of RNA‐specific Toll‐like receptors on health and disease

“…Live attenuated vaccines saved countless lives and have helped to eradicate or control serious infectious diseases such as smallpox, measles, or polio . The advantages of live vaccines include easier application (eg, orally or nasally), the long‐term protection, and that booster injections are often dispensable .…”

Disruption of the cpsE and endA Genes Attenuates Streptococcus pneumoniae Virulence: Towards the Development of a Live Attenuated Vaccine Candidate

“…S. pneumoniae live attenuated vaccines (LAVs) would ideally colonise in the upper respiratory tract of the host and induce effective immune protection by activating all phases of the immune system, provide more durable immunity that require boosters less frequently and have a lower cost. Attenuated vaccines are considered the most effective type of vaccine that induce durable immunity against diseases, with a lessened need for booster doses [22]. Unencapsulation is one of the effective strategies to attenuate the bacteria and to expose pneumococcal surface proteins to the immune system.…”