Vaccines
In 2020 we celebrate 75 years of the anniversary of our founding with a year of activities dedicated to demonstrating the impact of microbiologists’ past, present and future – bringing together and empowering communities that help shape the future of microbiology. We are launching new collections of digital content throughout the anniversary year. The third digital hub is ‘Vaccines: the global challenge for microbiology’, which will explore how vaccines work, how they are produced, herd immunity and disease eradication.
This Vaccine collection brings together the work of our journals on current and future vaccines, how they protect not just humans but animals as well, and how they are created.
Collection Contents
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Protective efficacy of an inactivated chimeric H5 avian influenza vaccine against H5 highly pathogenic avian influenza virus clades 2.3.4.4 and 2.3.2.1
More LessThe H5 subtype of highly pathogenic avian influenza (HPAI) viruses pose a serious challenge to public health and the poultry industry in China. In this study, we generated a chimeric QH/KJ recombinant virus expressing the entire haemagglutinin (HA)-1 region of the HPAI virus A/chicken/China/QH/2017(H5N6) (clade 2.3.4.4) and the HA2 region of the HPAI virus A/chicken/China/KJ/2017(H5N1) (clade 2.3.2.1). The resulting chimeric PR8-QH/KJ virus exhibited similar in vitro growth kinetics as the parental PR8-QH and PR8-KJ viruses. The chimeric PR8-QH/KJ virus induced specific, cross-reactive haemagglutination-inhibition and serum-neutralizing antibodies against both QH and KJ viruses, although PR8-QH and PR8-KJ exhibited no cross-reactivity with each other. Furthermore, the chimeric PR8-QH/KJ vaccine significantly reduced virus shedding and completely protected chickens from challenge with HPAI H5N6 and H5N1 viruses. However, the Re-8 vaccine against clade 2.3.4.4 viruses provided specific-pathogen-free chickens only partial protection when challenged with QH virus. Our results suggest that the antigenic variation of these epidemic viruses occurred and they can escape the current vaccine immunization. The Re-8 vaccine needs an update. The chimeric PR8-QH/KJ vaccine is effective against H5 HPAI virus clades 2.3.4.4 and 2.3.2.1 in chickens.
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Pasteurella multocida inactivated with ferric chloride and adjuvanted with bacterial DNA is a potent and efficacious vaccine in Balb/c mice
Purpose. Pasteurella multocida (P. multocida) is a principal pathogen of domestic animals and an opportunistic pathogen of humans. It is the causative agent of pneumonia and haemorrhagic septicaemia in cattle, sheep and goats, fowl cholera in chickens and progressive atrophic rhinitis in swine. In this study, we investigated the humoral and cellular immune responses and protective immunity conferred by an iron-inactivated vaccine with bacterial DNA (IIV+bDNA) as an adjuvant in mice.
Methodology. P. multocida was grown in BHI broth, inactivated with formalin and FeCl3 and adjuvanted with alum and bDNA. Mice were immunized with two whole-cell inactivated vaccine doses 2 weeks apart. The animals were challenged 4 weeks after booster immunization. Immunogens (vaccines and bDNA) posed no safety problems when mice were injected subcutaneously (s/c) with these preparations. The serum antibody titres were tested by ELISA. At 28 days post immunization, cell-mediated immunity responses were determined. The responses were measured by assay of IL-6 and IL-12 in lymphocyte spleen culture supernatants.
Results. ELISA results showed that the levels of antibodies in iron inactivated with bDNA adjuvant groups were higher than in the formalin inactivated with alum adjuvant vaccine group. The protection rate of IIV+bDNA adjuvant vaccine was superior to that of the other vaccines and it protected 100 % of the challenge group mice. Following immunization, bDNA promoted increased production of interleukins compared to the control groups.
Conclusion. These studies indicate that bDNA is effective as an immune adjuvant, and along with stimulatory bDNA represent promising new humoral and cellular immune enhancers for vaccination applications. In addition, this vaccine is able to provide long-term protection against infection.
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Pneumococcal vaccine impacts on the population genomics of non-typeable Haemophilus influenzae
The implementation of pneumococcal conjugate vaccines (PCVs) has led to a decline in vaccine-type disease. However, there is evidence that the epidemiology of non-typeable Haemophilus influenzae (NTHi) carriage and disease can be altered as a consequence of PCV introduction. We explored the epidemiological shifts in NTHi carriage using whole genome sequencing over a 5-year period that included PCV13 replacement of PCV7 in the UK’s National Immunization Programme in 2010. Between 2008/09 and 2012/13 (October to March), nasopharyngeal swabs were taken from children <5 years of age. Significantly increased carriage post-PCV13 was observed and lineage-specific associations with Streptococcus pneumoniae were seen before but not after PCV13 introduction. NTHi were characterized into 11 discrete, temporally stable lineages, congruent with current knowledge regarding the clonality of NTHi. The increased carriage could not be linked to the expansion of a particular clone and different co-carriage dynamics were seen before PCV13 implementation when NTHi co-carried with vaccine serotype pneumococci. In summary, PCV13 introduction has been shown to have an indirect effect on NTHi epidemiology and there exists both negative and positive, distinct associations between pneumococci and NTHi. This should be considered when evaluating the impacts of pneumococcal vaccine design and policy.
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Porcine circovirus type 1 was undetected in vaccine but could be cultured in the cell substrate of Lanzhou lamb rotavirus vaccine
More LessIn 2010, Rotarix was found to be contaminated with infectious porcine circovirus type 1 (PCV1). In China, the Lanzhou lamb rotavirus (LLR) vaccine is the only vaccine used to prevent rotavirus disease. From 2006 to September 2014, more than 54 million doses of LLR vaccines have been lot released. It is a safety issue whether PCV1 is present in the LLR vaccine. Although the cell substrate of LLR, bovine kidney (BK), is different from that of Rotarix, we have investigated the cell’s permissivity for PCV1 by both infectivity and full-length PCR analysis. We have assessed the LLR using a quantitative PCR (qPCR) assay. A total of 171 random batches of LLR final products over a period of 5 years were tested, and no PCV1 was detected (0/171). Infectivity studies showed that two strains of PCV1, the PCV1-prototype, which was derived from PK-15 cells, and the mutant, PCV1-GSK, which was isolated from Rotarix, were capable of replicating in BK cells over a wide m.o.i. ranging from 10 to 0.01. After culture for 6 days, copies of PCV1-prototype DNA were higher than those of PCV1-GSK on average. The genome of the virus was detected at 6 days post-infection. In summary, the LLR vaccine is free of PCV1. Nevertheless, because PCV1 can replicate in the BK cell substrate, manufacturers need to be vigilant in monitoring for this adventitious agent.
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