To the best of our knowledge, this study is the first to evaluate the cost implications and HCPs/parents’ perception of a switch from the current combination of Pentaxim® plus Hep B injections to a single Hexaxim® injection in the Malaysian NIP.
The economic evaluation results demonstrated that Hexaxim® had a lower cost per dose, per FIC, and per birth cohort (2019) and significant cost savings with regards to direct medical cost borne by HCP and direct non-medical cost (transportation) and indirect cost (loss of productivity) borne by parents/caregivers, compared with Pentaxim® plus Hep B. These results are supported by the results of a similar cost minimization study (from the public sector perspective only) conducted in South Africa in 2014 that also analyzed replacing Pentaxim® and Hep B vaccine with Hexaxim® vaccine . The direct medical cost saving per dose of Hexaxim® for the present study was RM 11.10 (in baseline scheme) compared with RM 7.4 (29.4 African rand) in the South African study . Moreover, based upon the costing profile generated in this study, it appeared that administration time was the cost component that contributed the most to the total direct cost per dose for Pentaxim® plus Hep B (86.9%) and Hexaxim® (80.9%). In contrast, Mogale et al. showed that cold chain storage was the major costing component for both partially and fully combined vaccines . This inconsistency arose due to the different methods used to calculate the administration cost. To assess the cost of cold chain storage, Mogale et al. have used the capital costs, which means that the researcher calculated how much space each vaccine would occupy compared with the refrigerator cost or cost of appliance. This method yielded a higher cost because of the expensive purchase price of vaccines appliances. In the current study, cold chain storage cost calculation was based upon the recurrent cost of energy for each dose of the vaccine, which resulted in a relatively minor contribution in the cost per dose compared with the other cost components for partially (0.009%) and fully combined (0.0009%) vaccines.
In the present study, the majority of parents believed that using Hexaxim® vaccine could reduce their child’s pain and discomfort compared with Pentaxim® plus Hep B. This was similar to a combination perception study conducted in the United States by Petraco and Judelsohn , where all parents wished that new childhood vaccinations would be available in a combination form, so that their infants do not have to get too many shots or injections to avert the extra pain they have to suffer. Per the Malaysian NIP, parents must make five vaccination visits during the first 6 months of their infants’ life, which increases the direct non-medical cost (transportation) and indirect cost (loss of productivity). The parents who participated in this study “Agreed” unanimously that replacing Pentaxim® and Hep B with Hexaxim® could reduce the number of visits and, consequently, the transportation expenses. Based upon that, majority of parents in this study believed that Hexaxim® incorporation in the immunization schedule could lead to more vaccination compliance. According to Hull and McIntyre , vaccination delays increase with number of doses or visits, where the number of immunizations and the complexity of the schedule are the primary reasons for vaccine dose deferrals and non-compliance. Most of the parents in this study demanded an immunization schedule review if there is a new vaccine, such as Hexaxim®, that can simplify the schedule.
In the present study, more than three-quarter of nurses believe that Pentaxim® vaccine reconstitution is a time loss because it requires too many steps to prepare, whereas Hexaxim® vaccine usage could reduce the work burden as it does not need reconstitution like Pentaxim®, which can save nurses’ time and efforts. Our finding is consistent with the result of a randomized, crossover, time and motion study conducted at Belgium by De Coster et al. , which reported that preparation time for non-fully liquid vaccine (70.5 s) was double than that for fully liquid vaccines (36.0 s). Furthermore, Pellissier et al. stated that time saving due to fully liquid vaccine can allow more time for patient education over a broad range of healthcare issues and increases the quality of care that HCPs can offer . Moreover, more than three-quarter of nurses in the current study believe that Pentaxim® reconstitution could lead to handling errors, which is consistent with the results of the time and motion study conducted by De Coster et al., where it was found that non-fully liquid vaccine reconstitution led to 24.48% of the immunization errors compared with 5.2% for the fully liquid vaccines . In the present study, the majority of nurses supported Hexaxim® employment in the vaccination schedule, which is consistent with De Coster et al.’s study  in which 97.6% of HCPs participated in the study preferred the use of the fully liquid vaccine in their daily clinical practice.
In the present study, more than three-quarter of physicians believe that Hexaxim® incorporation in the Malaysian NIP can produce substantial cost savings for both healthcare providers and parents. This is supported by the high percentage of positive perceptions regarding Hexaxim® obtained from parents and healthcare providers. This high percentage of agreement is due to two reasons: (1) physicians are aware of the limited budget dedicated to the health sector and (2) all the physicians participated in the study are medical officers who often deal with the financial issues of the health center. In the present study, the physicians’ perceptions analysis indicated that more than three-quarter of physicians’ believe that Hexaxim® usage could increase the parents’ compliance to the immunization program, which is a much higher percentage compared with the survey carried out in the United States in 2008 in which only 26.0% of physicians agreed that a combination vaccine would increase the parents’ compliance . This inconsistency is based upon the Malaysian physicians’ previous experience with Pentaxim® vaccine where they noticed an increased parents’ compliance to the NIP, compared with monovalent vaccines (Hep B or oral polio vaccine) used earlier. The current study finding is in line with the findings of Kalies et al. that the physicians’ perceptions toward parents’ better compliance if Hexaxim® is incorporated in the NIP . Kalies et al. found that combination vaccines were shown to be associated with improved timeliness of vaccination, with the percentage of subjects completing the full immunization series in time increasing with the use of higher valence vaccines. As a result of their positive perception regarding Hexaxim®, more than three-quarter of physicians supported using Hexaxim® in the immunization schedule.
The followings are the limitation of this study: (1) data were collected only from the PHCs of the states of Selangor and the Federal Territory of Kuala Lumpur due to limited budget and short study duration; (2) due to accessibility issues, two PHCs were excluded from the study plan; and (3) systematic sampling of nurses for MCH that have more than five nurses was not employed appropriately in some health centers since some nurses were absent or transferred to other departments on the day of data collection, which forced the researchers to choose convenient sample.
Based upon the results of this study, the following are the proposed recommendations for the Ministry of Health (MOH): (1) Hexaxim® vaccine can be adopted by the MOH and replace Pentaxim® and Hep B starting with the next birth cohort; (2) an evaluation study should be conducted to explore the satisfaction level of parents, nurses, and physicians after Hexaxim® vaccine usage; (3) the immunization schedule can be modified to exclude extra routine visits that does not include vaccination based upon the desire of the parents; (4) any current or future vaccines that need reconstitution can be replaced or not incorporated, since it can lead to handling errors or needlestick injury based upon nurses’ perceptions.