Immunogenicity and safety of a pentavalent acellular pertussis combined vaccine including diphtheria, tetanus, inactivated poliovirus and conjugated Haemophilus Influenzae type b polysaccharide for primary vaccination at 2, 3, 4 or 3, 4, 5 months of age in infants in China

Post-Marketing Safety Surveillance of a Childhood Pentavalent Diphtheria-Tetanus-Acellular Pertussis-Polio and Haemophilus influenzae Type B (DTaP-IPV//Hib) Vaccine in South Korea

INTRODUCTION

PENTAXIM™ (Sanofi), DTaP-IPV//Hib, a pentavalent combination vaccine for protection against diphtheria, tetanus, pertussis, poliomyelitis, and invasive infections caused by Haemophilus influenzae type b, has been licensed in South Korea by the Ministry of Food and Drug Safety (MFDS) on May 9, 2016, and is currently used in routine vaccination. The aim of this phase IV study, conducted as a post-licensure commitment in South Korea, was to evaluate the safety of the DTaP-IPV//Hib vaccine when administered in infants at 2, 4, and 6 months of age in the real-world clinical practice.

METHODS

This multicenter, observational, post-marketing surveillance (PMS) study was conducted in real-world practice in South Korea. Infants aged 2 months or older were enrolled across seven centers from July 31, 2018 to February 11, 2020. The study outcomes included occurrence, time to onset, duration, intensity, and causality assessment (for unsolicited adverse events [AEs] only) for several pre-listed solicited injection-site and systemic reactions, unsolicited AEs, and serious adverse events (SAEs).

RESULTS

Data from 619 participants were included in the safety analysis. Overall, 618 AEs were reported by 273 (44.1%) participants consisting of 121 solicited injection-site reactions (15.4%), 344 solicited systemic reactions (24.6%), and 153 unsolicited AEs (15.7%) of which, 124 were unexpected AEs (12.9%) (regardless of intensity). None of the unsolicited AEs were reported to have a causal relationship with the study vaccine. One SAE of pyrexia (solicited reaction) was reported. Most AEs were of mild intensity, and all participants recovered.

CONCLUSION

This PMS study of the DTaP-IPV//Hib vaccine confirmed its safety profile in a real-life setting in South Korea and justified that the vaccine is well tolerated when used in infants aged 2 months or older for the primary series.

Economic impact of switching from partially combined vaccine "Pentaxim® and hepatitis B" to fully combined vaccine "Hexaxim®" in the Malaysian National Immunization Program

Background

The decision to implement new vaccines should be supported by public health and economic evaluations. Therefore, this study was primarily designed to evaluate the economic impact of switching from partially combined vaccine (Pentaxim® plus hepatitis B) to fully combined vaccine (Hexaxim®) in the Malaysian National Immunization Program (NIP) and to investigate healthcare professionals (HCPs)’ and parents’/caregivers’ perceptions.

Methods

In this economic evaluation study, 22 primary healthcare centers were randomly selected in Malaysia between December 2019 and July 2020. The baseline immunization schedule includes switching from Pentaxim® (four doses) and hepatitis B (three doses) to Hexaxim® (four doses), whereas the alternative scheme includes switching from Pentaxim® (four doses) and hepatitis B (three doses) to Hexaxim® (four doses) and hepatitis B (one dose) administered at birth. Direct medical costs were extracted using a costing questionnaire and an observational time and motion chart. Direct non-medical (cost for transportation) and indirect costs (loss of productivity) were derived from parents’/caregivers’ questionnaire. Also, HCPs’ and parent’s/caregivers’ perceptions were investigated using structured questionnaires.

Results

The cost per dose of Pentaxim® plus hepatitis B vs. Hexaxim® for the baseline scheme was Malaysian ringgit (RM) 31.90 (7.7 United States dollar [USD]) vs. 17.10 (4.1 USD) for direct medical cost, RM 54.40 (13.1 USD) vs. RM 27.20 (6.6 USD) for direct non-medical cost, RM 221.33 (53.3 USD) vs. RM 110.66 (26.7 USD) for indirect cost, and RM 307.63 (74.2 USD) vs. RM 155.00 (37.4 USD) for societal (total) cost. A similar trend was observed for the alternative scheme. Compared with Pentaxim® plus hepatitis B, total cost savings per dose of Hexaxim® were RM 137.20 (33.1 USD) and RM 104.70 (25.2 USD) in the baseline and alternative scheme, respectively. Eighty-four percent of physicians and 95% of nurses supported the use of Hexaxim® in the NIP. The majority of parents/caregivers had a positive perception regarding Hexaxim® vaccine in various aspects.

Conclusions

Incorporation of Hexaxim® within Malaysian NIP is highly recommended because the use of Hexaxim® has demonstrated substantial direct and indirect cost savings for healthcare providers and parents/caregivers with a high percentage of positive perceptions, compared with Pentaxim® plus hepatitis B.

Trial registration

Not applicable.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12913-021-07428-7.

Bordetella pertussis Infection in Infants and Young Children in Shanghai, China, 2016-2017: Clinical Features, Genotype Variations of Antigenic Genes and Macrolides Resistance

BACKGROUND

The global resurgence of pertussis in countries with high vaccination coverage has been a concern of public health.

METHODS

Nasopharyngeal swabs were collected for Bordetella pertussis culture from children with suspected pertussis. Clinical and vaccination information were reviewed through electronic medical chart and immunization record. Antibiotics susceptibility was evaluated using E-test for erythromycin, azithromycin, clarithromycin and sulfamethoxazole/trimethoprim. The MLST genotypes and 7 antigenic genes (ptxP, ptxA, ptxC, Prn, fim3, fim2 and tcfA) of Bordetella pertussis were identified by polymerase chain reaction amplification and sequencing.

RESULTS

During January 2016 to September 2017, a total of 141 children 1-48 months of age were culture-confirmed with pertussis, of whom 98 (69.5%) were younger than 6 months, 25 (17.7%) had completed at least 3 doses of DTaP and 75 (53.2%) had a clear exposure to household members with persistent cough. Fully vaccinated cases manifested milder disease than unvaccinated and not-fully vaccinated cases. All strains were MLST2. High-virulent strains characteristic of ptxP3/prn2/ptxC2 constituted 41.1% (58/141) and were all susceptible to macrolides while low-virulent strains characteristic of ptxP1/prn1/ptxC1 constituted 58.9% (83/141) and 97.6% (81/83), respectively, were highly resistant to macrolides.

CONCLUSIONS

Pertussis is resurging among infants and young children in Shanghai, and household transmission is the main exposure pathway. The high-virulent strains harboring ptxP3/prn2/ptxC2 and the macrolide-resistant Bordetella pertussis strains are quite prevalent. These issues impose a public health concern in Shanghai. Our findings are important to modify the DTaP vaccination strategy and the management guideline of pertussis in China.

Determination of Depth-Dependent Intradermal Immunogenicity of Adjuvanted Inactivated Polio Vaccine Delivered by Microinjections via Hollow Microneedles

PURPOSE

The aim of this study was to investigate the depth-dependent intradermal immunogenicity of inactivated polio vaccine (IPV) delivered by depth-controlled microinjections via hollow microneedles (HMN) and to investigate antibody response enhancing effects of IPV immunization adjuvanted with CpG oligodeoxynucleotide 1826 (CpG) or cholera toxin (CT).

METHODS

A novel applicator for HMN was designed to permit depth- and volume-controlled microinjections. The applicator was used to immunize rats intradermally with monovalent IPV serotype 1 (IPV1) at injection depths ranging from 50 to 550 μm, or at 400 μm for CpG and CT adjuvanted immunization, which were compared to intramuscular immunization.

RESULTS

The applicator allowed accurate microinjections into rat skin at predetermined injection depths (50-900 μm), -volumes (1-100 μL) and -rates (up to 60 μL/min) with minimal volume loss (±1-2%). HMN-mediated intradermal immunization resulted in similar IgG and virus-neutralizing antibody titers as conventional intramuscular immunization. No differences in IgG titers were observed as function of injection depth, however IgG titers were significantly increased in the CpG and CT adjuvanted groups (7-fold).

CONCLUSION

Intradermal immunogenicity of IPV1 was not affected by injection depth. CpG and CT were potent adjuvants for both intradermal and intramuscular immunization, allowing effective vaccination upon a minimally-invasive single intradermal microinjection by HMN.

Adjuvants and inactivated polio vaccine: a systematic review

Poliomyelitis is nearing universal eradication; in 2011, there were 650 cases reported globally. When wild polio is eradicated, global oral polio vaccine (OPV) cessation followed by use of universal inactivated polio vaccine (IPV) is believed to be the safest vaccination strategy as IPV does not mutate or run the risk of vaccine derived outbreaks that OPV does. However, IPV is significantly more expensive than OPV. One strategy to make IPV more affordable is to reduce the dose by adding adjuvants, compounds that augment the immune response to the vaccine. No adjuvants are currently utilized in stand-alone IPV; however, several have been explored over the past six decades. From aluminum, used in many licensed vaccines, to newer and more experimental adjuvants such as synthetic DNA, a diverse group of compounds has been assessed with varying strengths and weaknesses. This review summarizes the studies to date evaluating the efficacy and safety of adjuvants used with IPV.

The safety advantages of pentavalent vaccines

The ever-growing vaccination schedule can cause patients, parents, and nurse practitioners undue concern. Combination vaccines may provide an answer. This integrative review demonstrates that pentavalent vaccines offer adequate immunity, are well tolerated, and safe when compared to vaccines administered separately.