Considerations for hepatitis B as part of a combination vaccine

A worldwide overview for hexavalent vaccines and a glimpse into Turkiye's perspective

The surge in recommended vaccinations for child's has spurred the development of combination vaccines, notably hexavalent vaccines, which provide multiple immunizations in a single dose. These vaccines offer various advantages, such as streamlining vaccination schedules, minimizing injection-related pain and exposure to preservatives, expanding vaccine coverage, and reducing administration costs. However, the intricate and expensive development of these vaccines presents substantial challenges, requiring increased investment and healthcare provider education to optimize their utilization and sustain high vaccination rates. Turkey, known for its robust vaccine coverage, strategic geographic location, and the influx of refugees, is at a critical juncture for integrating hexavalent vaccines into national programs. This transition is especially relevant given the rising vaccine hesitancy and the potential resurgence of vaccine-preventable diseases. This review assesses the deployment of hexavalent vaccines, examining their benefits and challenges through clinical trials and global experiences, with a specific emphasis on Turkiye's public health context.

PEDIARIX™: clinical trials

PEDIARIX is the first pentavalent combination vaccine licensed for use in infants in the USA. This vaccine is indicated for the prevention of diphtheria, tetanus, pertussis, hepatitis B and poliovirus. This article reviews the available data regarding the vaccine's immunogenicity and safety.

Characterization and immune effect of the hepatitis B-BCG combined vaccine for using a needle innoculation

OBJECTIVE

To prepare the hepatitis B-Mycobacterium bovis Bacillus Calmette-Guérin combined vaccine (HB-BCG combined vaccine) and resolve a needle problem of the two kinds of hepatitis B vaccine (HB vaccine) and M. bovis Bacillus Calmette-Guérin (BCG) for the innoculation.

METHODS

The hepatitis B surface antigen (HBsAg) was prepared by the genetic engineering technique, BCG was produced using routine biological technique, and then the finished products of the HB-BCG combined vaccine were processed on the above foundation. The content of HBsAg was measured by Enzyme linked immunosorbent assay (ELISA), the immune effect of BCG was detected by purified protein derivative (PPD) test. Cellular immune response, safety, partial poison and allergy were tested. The stability of HB-BCG combined vaccine was detected by ELISA and viable count method.

RESULTS

The two kinds of antigens (HBsAg and BCG) had good compatibility. The comparison on immune effects of HB-BCG combined vaccine and BCG showed no significant difference. The comparison on immune effects of HB-BCG combined vaccine group (first dose for HB-BCG Combined vaccine, second and third dose for HB vaccine) and HB vaccine group (three dose all for HB vaccine) demonstrated that anti-HBs levels of the HB-BCG combined vaccine group were higher than that of HB vaccine group. No statistical significance was observed between the combined vaccine group and HB vaccine group after three doses immunization schedules. The results of safety in HB-BCG combined vaccine group accorded with that of BCG group, it had been not found the pathological changes of the tuberculosis. The characteristic and process in pathological changes of HB-BCG combined vaccine group and BCG group were similar in the partial poison test. HBsAg did not strengthen the inflammation reaction caused by BCG. Systemic allergy had not been found. The HB-BCG combined vaccine was stable in 2 years.

CONCLUSION

The immune effects of the HB-BCG combined vaccine were not lower than the two kinds of single dose vaccine, it had good safety.

Acute Otitis Media Due to Penicillin-Nonsusceptible Streptococcus pneumoniae Before and After the Introduction of the Pneumococcal Conjugate Vaccine

BACKGROUND

The impact of the 7-valent pneumococcal conjugate vaccine (PCV7 [Prevnar]) on penicillin-nonsusceptible Streptococcus pneumoniae (PNSP) recovered from children with acute otitis media (AOM) is unclear.

METHODS

At 5 hospitals, 505 pneumococcal isolates were collected from children with AOM between 1 January 1999 and 31 December 2002. Molecular subtyping was performed on 158 isolates.

RESULTS

Overall, the percentage of AOM cases due to non-PCV7 serogroups (including serotype 3) increased over time (from 12% in 1999 to 32% in 2002; P < .01) and according to the number of PCV7 doses received (18% [< or = 1 dose] vs. 35% [2-4 doses]; P < .01). The percentage of cases due to vaccine-related serotypes (including serotype 19A) increased according to the number of PCV7 doses received (10% [< or = 1 dose] vs. 19% [2-4 doses]; P = .05) but not over time, whereas the percentage of cases due to serotype 19F remained unchanged both over time and according to the number of PCV7 doses received. The frequency of penicillin nonsusceptibility among PCV7 serotypes (range, 65%-75%) and non-PCV7 serogroups (range, 11%-27%) did not significantly change overall. Although no change was detected among isolates collected from children with spontaneous drainage, the percentage of pneumococci recovered at the time of myringotomy and/or tympanostomy tube placement that were nonresistant to penicillin decreased over time (from 73% in 1999 to 53% in 2002; P = .03). All of the serotype 3 strains were genetically related, whereas 88% of the isolates that were either serotype 19F or serotype 23F were related to 1 of 3 international clones.

CONCLUSIONS

Among children with AOM, the proportion of cases due to non-PCV7 serogroups increased, vaccine-related serotypes increased, and serotype 19F remained unchanged. Although a decrease in the proportion of cases due to PNSP occurred among children who required myringotomy and/or tympanostomy tube placement, the proportion of PNSP remained unchanged overall and among children with spontaneous drainage. Because future trends in the susceptibility patterns of pneumococcal isolates recovered from children with AOM are not easy to predict, continued surveillance is essential.

Combined hepatitis B vaccines

The status and likely impact of existing and potential new combined hepatitis B vaccines were broadly considered at the Viral Hepatitis Prevention Board (VHPB) meeting in Malta, October 2001. The currently available and/or licensed combined hepatitis B vaccines in Europe and the prospects for further such vaccines were reviewed. Data on the safety, immunogenicity, and European licensing status and availability of haxavalent vaccines combining hepatitis B (HepB), Haemophilus influenza type b (Hib), diphtheria, tetanus, and pertussis (acellular) (DTPa), and inactivated poliovirus (IPV) antigens were presented. Finally, the impact of the availability of combined hepatitis B vaccines on hepatitis B immunisation programmes in Europe were examined and the added value of combined hepatitis B vaccines globally was estimated.