Combination Vaccines

Combination vaccines have been around since 1945 (trivalent influenza vaccine) and they combine either different serotypes of one microorganism (e.g., influenza or pneumococcal vaccines) or different microorganisms (e.g., DTP combinations). Potential chemical and physical interactions, unpredictable immunological interactions, and in one instance: increased AE, increasing likelihood of production failures, and reduced flexibility of a vaccination program are challenges for developing combination vaccines. With an increasing number of new vaccines for protecting the very young, DTaP- and DTwP-based combinations have become the cornerstone of pediatric vaccination programs around the globe since the mid-1990s. Live vaccine combinations include MR, MMR, and MMRV combinations as well as (trivalent) OPV. Combination vaccines for travelers include HAV-HBV combination and HAV-Ty vaccines. Dozens of diverse combination vaccine products are licensed today around the globe, some of them only in single countries to cover specific local needs. Combination vaccines have been shown to result in increased acceptance, completion and compliance with vaccination programs; in addition, they offer simplified logistics, reduce administration errors, reduce the number of medical visits and cost for the individual as well as for society, among other benefits.

Safety and Immunogenicity of Mix-Match of Vaccines -Covishield and Covaxin – a Pilot Study

This single-center prospective observational study was conducted to assess the safety and immunogenicity of combination vaccines AstraZeneca’s ChAdOx1-nCov-19 (Covishield in India) and inactivated whole virion BBV152 (Covaxin). A total of 330 unvaccinated healthy volunteers were screened for SARS-COV2 seropositivity. RT PCR tests were conducted for seronegative volunteers (n =44). They were randomly assigned to four groups and given either same or mixed vaccines at an interval of 4 weeks between the two doses. Mix and match of vaccines did not evoke any adverse events. Combination of vaccines elicited similar immune responses in 4 groups. They were further studied dividing into homologous and heterologous vaccine groups. In Conclusion, Combination vaccines are safe and immunogenic and heterologous vaccines elicit better immunogenic response.

Safety and Immunogenicity of Combination of Vaccines – Covishield and Covaxin – a Pilot Study

This single-center prospective observational study was conducted to assess the safety and immunogenicity of combination vaccines AstraZeneca’s ChAdOx1-nCov-19 (Covishield in India) and inactivated whole virion BBV152 (Covaxin). A total of 330 unvaccinated healthy volunteers were screened for SARS-COV2 seropositivity. RT PCR tests were conducted for seronegative volunteers (n =44). They were randomly assigned to four groups and given either same or mixed vaccines at an interval of 4 weeks between the two doses. Mix and match of vaccines did not evoke any adverse events. Combination of vaccines elicited similar immune responses in 4 groups. In Conclusion, Combination vaccines are safe and immunogenic.

Pertussis

The bacterium Bordetella pertussis causes disease by producing various virulence and adhesion factors, among them pertussis toxin (PT), filamentous hemagglutinin (FHA), pertactin (PRN) and agglutinogens (Agg), also called fimbriae (FIM) "Typical" pertussis or whooping cough starts with unspecific respiratory symptoms (catarrhal phase) followed by severe coughing spasms with whoops and vomiting (paroxysmal phase) and only after weeks or months disease severity slowly wanes (convalescent phase). "Atypical pertussis" with unspecific, long-lasting coughing episodes is seen in adolescents and adults; very young infants may die from apnoea. B. pertussis is transmitted by droplets, and neither infection nor vaccination produce long lasting protection. Macrolide antibiotics are given to patients and their contacts to reduce spread of the organism; however, antibiotics do NOT change the duration or course of the disease once symptoms are present. Whole cell pertussis vaccines (wP) consist of whole inactivated B. pertussis-cells, whereas acellular vaccines (aP) consist of one to five single components like PT, FHA, PRN or FIM. Pertussis vaccines are currently only available as combination vaccines with tetanus und diphtheria (DTP). Among these are DTwP; DTaP; TdaP; and various DTP-combinations with Hib, IPV, HBV vaccines. Whole cell pertussis (DTwP) combination vaccines are more reactogenic, whereas DTaP vaccines are generally well tolerated. Some DTwP had good efficacy/effectiveness (90%), it was low (40%) with others. Vaccine efficacy of DTaP vaccines ranges between 70% and 90%. As with most vaccines, efficiency is higher for severe disease. While pertussis vaccines did control clinical disease, protection is limited. Vaccination is recommended for all infants (three doses) worldwide with a booster in the second year of life. Many countries give additional doses at school entry and in adolescents, and some to adults. Vaccination of pregnant women effectively protects newborn infants and is increasingly recommended.

Pertussis

The bacterium Bordetella pertussis causes disease by producing various virulence and adhesion factors, among them pertussis toxin (PT), filamentous hemagglutinin (FHA), pertactin (PRN) and agglutinogens (Agg), also called fimbriae (FIM) "Typical" pertussis or whooping cough starts with unspecific respiratory symptoms (catarrhal phase) followed by severe coughing spasms with whoops and vomiting (paroxysmal phase) and only after weeks or months disease severity slowly wanes (convalescent phase). "Atypical pertussis" with unspecific, long-lasting coughing episodes is seen in adolescents and adults; very young infants may die from apnoea. B. pertussis is transmitted by droplets, and neither infection nor vaccination produce long lasting protection. Macrolide antibiotics are given to patients and their contacts to reduce spread of the organism; however, antibiotics do NOT change the duration or course of the disease once symptoms are present. Whole cell pertussis vaccines (wP) consist of whole inactivated B. pertussis-cells, whereas acellular vaccines (aP) consist of one to five single components like PT, FHA, PRN or FIM. Pertussis vaccines are currently only available as combination vaccines with tetanus und diphtheria (DTP). Among these are DTwP; DTaP; TdaP; and various DTP-combinations with Hib, IPV, HBV vaccines. Whole cell pertussis (DTwP) combination vaccines are more reactogenic, whereas DTaP vaccines are generally well tolerated. Some DTwP had good efficacy/effectiveness (90%), it was low (40%) with others. Vaccine efficacy of DTaP vaccines ranges between 70% and 90%. As with most vaccines, efficiency is higher for severe disease. While pertussis vaccines did control clinical disease, protection is limited. Vaccination is recommended for all infants (three doses) worldwide with a booster in the second year of life. Many countries give additional doses at school entry and in adolescents, and some to adults. Vaccination of pregnant women effectively protects newborn infants and is increasingly recommended.

Safety evaluation following immunization of pentavalent vaccine (multi-dose vial): experiences and comparative study

Background: Combination vaccines have many benefits but sometimes may result in unexpected side effects which may make the vaccine unfit for administration particularly with multidose vials.Methods: Healthy infants aged 6-8 weeks who came for routine immunization of liquid pentavalent vaccine were included in the study. All infants were observed for 30 minutes, post vaccination. Telephonic interview was conducted to detect AEFIs at 1 week and 1 month post vaccination.Results: The common AEFIs were found to be fever and pain at injection site. A comparison of the incidence (per 100 doses) of AEFIs after 1st, 2nd and 3rd dose of pentavalent vaccine showed that AEFIs goes on reducing with dose. Incidence (per 100 doses) of fever and local AEFIs was more (statistically significant) with multi-dose vial pentavalent vaccine.Conclusions: The multi-dose vial liquid pentavalent vaccine was found to be equally tolerable compared to single-dose vial liquid pentavalent vaccine.