Suitability and uptake of vaccines in the last 4 weeks among child participants of a health screening campaign

Over the years, vaccines have caused some controversy over its safety but there are no convincing proof of harm that has been found. In Malaysia, vaccines such as Hepatitis B and Haemophilus influenzae are compulsory for infants and children up to 15 years old by the Ministry of Health. Vaccine can be described as a tool available to parents to protect their infants and children from potentially deadly diseases.¹ A vaccine is a weaker version or part of the germ that is causing the disease. It contains the same antigen as the disease. When the infection in vaccine form is inserted in children, their immune system is triggered to make antibodies that protect them from catching the disease when they are exposed to the actual disease in question.²

The main use of vaccines is that they protect children against common deadly diseases such as polio, measles, diphtheria and so on. They stimulate the immune system to synthesize antibodies, thus enhancing immunity and providing protection to the child.³ Immunization is considered as the most cost-effective public health intervention, preventing an estimated 2 to 3 million deaths yearly.⁴ Vaccination also helps in the case of newborn babies. Babies receive antibodies from their mother but after a year of life, immunity wears out. Therefore, vaccines boost their immunity. Unvaccinated kids are at higher risk and more vulnerable to the disease than the accinated ones.⁵

In Malaysia, the WHO Expanded Programme on Immunisation provides free vaccination to children since birth up to fifteen years of age. Notwithstanding the huge success of increased immunization coverage rates (>90%) in Malaysia, the hesitancy for vaccine uptake prevails as a rising concern denoted by increasing number of diseases that can potentially be eliminated by vaccines.⁶ A ten-fold spike in measles was observed in 2013 to 2018 by the Malaysian Health Ministry from 125 to 1467 respectively. Even though vaccine coverage has been more than 95% consistently, vaccine uptake for measles indicated a decrease in 2017 to 88.8%.⁷ Few reasons behind vaccine refusals are religious exemptions, philosophical disapproval like desiring a natural living or overstated concerns for vaccine safety such as relating autism to childhood vaccination. However, no such link regarding autism has been proven by reputed studies.⁸ Furthermore, lack of knowledge about vaccinations causing misconceptions, or impact of wrong information shared online as well as former unpleasant incidents regarding vaccination are other reasons.⁹ This hesitancy could develop into refusal leading to more unvaccinated children, resulting in outbreaks of vaccine-preventable diseases.¹⁰ Therefore, the suitability and uptake of vaccines among children in a health screening campaign are further explored in this study.

Materials and methods

A cross-sectional, prospective observational study was conducted at two communities through health campaign. Ethical approval was sought with the Medical Research Ethics Committee, Universiti Putra Malaysia. All participants provided their written informed consent. The inclusion criteria were Malaysian parents aged 18 years and above who were attending the health campaign and who could understand and complete the questionnaires in English or Malay version. The exclusion criteria comprise of those who has mental health issues.

Universal sampling was used to recruit respondents in this study. Those who fulfilled the inclusion criteria was taken as respondents in this study. A validated and self-administered questionnaire that includes two sections on socio-demographic details and a section on child vaccination practices was used.

The respondents need to take approximately about 10 to 15 minutes to complete all the questions in the questionnaires. A written informed consent will be taken before the process of data collection started. All information of the respondents remains confidential and is solely for research purpose. 

Operational Definition

The independent variables for this study are:

1. Sociodemographic characteristics which include age, gender, ethnicity, educational status, marital status and occupation of the parent

Dependent factors are:

1. Child vaccination practices

For data analysis of the raw data this study, Statistical Package for Social Sciences v26.0 was used. Descriptive analysis was used to analyze the data distribution normality, frequencies, means and standard deviation.

Results

The mean age is 50.1±22.7 years. Majority were females (68.3%), of Chinese ethnicity (21.7%), married (73.3%) and not employed (75.0%). Majority had none or primary level of education only (60.0%). Majority of the children were suitable to receive vaccine i.e. 58/60 or 96.7%. (Table 1)

Discussion

Immunization in children has been a great success in the public health sector for a long time. However, the suitability and uptake of vaccines during childhood has raised concerns whether acute diseases decrease the efficiency or elevate the adverse reactions of vaccines. Vaccine comprises an active ingredient which is the antigen that gives rise to the immune response, along with other components including preservatives, additives and adjuvants. Some children are prone to allergies to these components, mainly foods such as eggs (60% at 6 years).¹¹ 

Several vaccines produced on embryonated chicken eggs contain egg proteins, mainly ovalbumin with high amounts present in influenza, yellow fever and rabies which are embryonated chicken eggs vaccines while reduced amounts in Measles-Mumps-Rubella (MMR) or tick-borne encephalitis vaccines which are chicken embryos or fibroblasts of chicken embryos vaccines. However, children with mild allergies can uptake any influenza vaccines or MMR vaccine safely without hospital admission while children with severe allergies require a medical setting intervention or hospital admission for vaccination.¹² Moreover, hidden milk proteins may be present in a few vaccines to avoid virus degradation. Allergic reactions have been observed following MMR vaccine in children with milk and egg allergy.¹³ In OPV (Oral Polio Vaccine) and DPT (diphtheria, pertussis and tetanus) vaccine, existence of milk proteins is suggested and therefore, children with allergic reaction history are recommended on a 60 min observation following vaccination.¹⁴ 

Although anaphylactic reaction to yeast is considered rare, those who have such allergy are suggested to take only yeast-free vaccines such as bivalent human papillomavirus vaccine, over vaccines that has yeast proteins including quadrivalent human papillomavirus vaccine or hepatitis B vaccine.¹⁵ Furthermore, gelatin which acts as a stabilizer in many vaccines is responsible for major allergic events including IgE as well as non-IgE induced reactions.¹⁶ However, a reduction in allergic events is noticed with greater hydrolysed porcine gelatin in use within these vaccines.¹⁷ The risk group includes children allergic to red-meat like bovine, pork or lamb where pork-meat sensitive children (38%) already have particular IgE towards gelatin thereby increasing the risk of anaphylactic reactions during vaccination.¹⁸ In order to avoid bacterial or fungal contaminants in vaccines, small amounts of antibiotics are used, like neomycin, streptomycin etc. However, few adverse events from case reports have been outlined.¹⁹ Moreover, some children are allergic to latex which is found in the vial or syringe of vaccines. However, hypersensitivity events are uncommon in the case of vaccine contaminated by latex. Latex free vaccines are available at present.¹³

In the case of adverse reactions to vaccines in the past, future doses are contraindicated. However, there are circumstances where benefits are more than the risks like the event of an outbreak.²⁰ Blood disorders such as thrombocytopenia or thrombocytopenic purpura could be a precaution for MMR as well as MMRV vaccines.²¹ How safe the live attenuated influenza vaccines (LAIV) in children with lung, heart, kidney or metabolic diseases such as diabetes or any blood disorder is not confirmed yet. However, children from the age of 5 undergoing these disorders, as well as asthma should be carefully dealt with prior to vaccination with LAIV.²² Moreover, Inactivated Influenza Vaccine is recommended for children on long-term aspirin therapy as well as children who have had wheezing or asthma in the past 12 months from 2 to 4 years of age while use of LAIV is advised against. However, there is no proof of increased wheezing following LAIV vaccination in those who have had previous wheezing or asthma history and it has not been identified if wheezing would have taken place without LAIV immunization.²³ 

Children with epilepsy are known to develop fever and infection that can potentially trigger seizures. Some vaccines such as measles-mumps-rubella (MMR) vaccines, trivalent inactivated influenza vaccines have been linked to febrile seizures in young children in the past.²⁴ After immunization in children having epilepsy, the risk of seizure is not known. A study was done to determine the risk of seizure after immunization in children (less than 7 years old) with epilepsy.²⁵ From the results obtained, it was seen that parents can be at ease as immunization does not appear to cause an increase of seizure in children with epilepsy. However, further studies are required to confirm these findings. 

Together with its role in boosting the immune system, vaccination has also been seen as a potential modifier of the risk of childhood leukaemia. According to a study carried out by Xiaomei et al, it was seen that vaccinations such as diphtheria and tetanus are not associated with the risk of leukaemia and that Hib vaccination has the ability to reduce the risk of childhood leukaemia.²⁶ In the case of HIV, most children who are born to women are already infected with human immunodeficiency (HIV) do not get infected but some acquire the virus at the time of delivery or shortly after.  Nevertheless, it was seen that immunization is usually safe and beneficial for HIV-infected children, despite the fact that HIV-induced immune suppression diminishes the benefit compared with that received in HIV-uninfected children.²⁷ But it should be noted that some complications can happen after immunization in the case of severely immunocompromised children but there is no evidence that immunization accelerates the course of HIV infection.²⁸ 

As for children taking anticancer medication or are under chemotherapy, vaccination should be put to a halt. Cancer chemotherapy is known to suppress the immune system.²⁹ The decrease is most noticeable during the induction and consolidation chemotherapy. After the completion of all therapies, immune functions take months to recover to normal. Primary immunization responses are more affected by immunosuppression than booster responses.³⁰ Hence, vaccination should not be conducted during induction and consolidation chemotherapy. Other vaccinations options exist in the period of maintenance therapy. Killed vaccines are used in immunosuppressed children as they are less risky but they may not be as effective as the live viral vaccines. Live bacterial vaccines such as the Bacille Calmette-Guérin, oral typhoid should also be avoided.³¹ 

As for those who are receiving a blood transfusion or blood products, it is better to delay vaccines for a certain period of time. Immunoglobulins have the ability to inhibit the immune response to some vaccines.³² However, according to the CDC, a blood transfusion at the age of 3 days should not have a great impact on the routine immunization schedule. The varicella and the MMR vaccine would not be due for one year and the precautions associated with blood transfusion are usually for the previous eleven months infants only. As for the whole blood is concerned, the wait to administer MMR or varicella-containing vaccine is around 6 months.³³

Strength of the study lies in the important data collected which indicate that majority of parents are adhering calls for their child to be vaccinated. Limitation lies in the fact that this is a cross sectional study which may limit causality and the small sample size which may limit its generalisability.

Conclusion

The uptake of children in receiving vaccine is high. This augurs well for a nation keen to have healthy citizens that can spur the economy.

Acknowledgement

We would like to thank the participants of this study.

References

1. Heikkinen, T., Booy, R., Campins, M., Finn, A., Olcén, P., Peltola, H., … Weil-Olivier, C. (2005). Should healthy children be vaccinated against influenza? European Journal of Pediatrics, 165(4), 223–228.
2. Weiner, J. L., Fisher, A. M., Nowak, G. J., Basket, M. M., & Gellin, B. G. (2015). Childhood immunizations: first-time expectant mothers’ knowledge, beliefs, intentions, and behaviors. American journal of preventive medicine, 49(6), S426-S434.
3. Kapikian, A. Z., Mitchell, R. H., Chanock, R. M., Shvedoff, R. A., & Stewart, C. E. (1969). An epidemiologic study of altered clinical reactivity to respiratory syncytial (RS) virus infection in children previously vaccinated with an inactivated RS virus vaccine. American journal of epidemiology, 89(4), 405-421.
4. Stashko, L. A., Gacic-Dobo, M., Dumolard, L. B., & Danovaro-Holliday, M. C. (2019). Assessing the quality and accuracy of national immunization program reported target population estimates from 2000 to 2016. PloS one, 14(7), e0216933.
5. Santoli, J. M., Rodewald, L. E., Maes, E. F., Battaglia, M. P., & Coronado, V. G. (1999). Vaccines for Children Program, United States, 1997. Pediatrics, 104(2), e15–e15.
6. Krishna, D., Zulkefli, N. A. M., Said, S. M., & Mahmud, A. (2019). Sociodemographic and health care factors in determining immunization defaulters among preschool children in Petaling District, Selangor: a cross-sectional study in Malaysia. BMC public health, 19(1), 1275.
7. Kalok, A., Loh, S. Y. E., Chew, K. T., Abdul Aziz, N. H., Shah, S. A., Ahmad, S., … Abdullah Mahdy, Z. (2020). Vaccine hesitancy towards childhood immunisation amongst urban pregnant mothers in Malaysia. Vaccine. 
8. Arora, K. S., Morris, J., & Jacobs, A. J. (2018). Refusal of Vaccination: A Test to Balance Societal and Individual Interests. The Journal of clinical ethics, 29(3), 206–216.
9. Khoo, Y., Ghani, A. A., Navamukundan, A. A., Jahis, R., & Gamil, A. (2020). Unique product quality considerations in vaccine development, registration and new program implementation in Malaysia. Human vaccines & immunotherapeutics, 16(3), 530–538.
10. Lim, K. K., Chan, Y. Y., Noor Ani, A., Rohani, J., Siti Norfadhilah, Z. A., & Santhi, M. R. (2017). Complete immunization coverage and its determinants among children in Malaysia: findings from the National Health and Morbidity Survey (NHMS) 2016. Public Health, 153, 52–57.
11. Savage, J. H., Matsui, E. C., Skripak, J. M., & Wood, R. A. (2007). The natural history of egg allergy. Journal of Allergy and Clinical Immunology, 120(6), 1413-1417.
12. See, T. M., Jin, T. E., Peng, H. C., & Chiee, A. Y. A. (2016). Measles-Mumps-Rubella vaccine for children with egg allergy: Is admission for inpatient vaccination necessary. J. Malaysia.
13. Yavuz, S. T., Sahiner, U. M., Sekerel, B. E., Tuncer, A., Kalayci, O., & Sackesen, C. (2011). Anaphylactic reactions to measles–mumps–rubella vaccine in three children with allergies to hen’s egg and cow’s milk. Acta Paediatrica, 100(8), e94-e96.
14. Slater, J. E., Rabin, R. L., & Martin, D. (2011). Comments on cow's milk allergy and diphtheria, tetanus, and pertussis vaccines. Journal of Allergy and Clinical Immunology, 128(2), 434.
15. Kelso, J. M. (2013). Allergic reactions after immunization. Annals of Allergy, Asthma & Immunology, 110(6), 397-401.
16. Lasley, M. V. (2007). Anaphylaxis after booster influenza vaccine due to gelatin allergy. Pediatric Asthma, Allergy & Immunology, 20(3), 201-205.
17. Nakayama, T., & Aizawa, C. (2000). Change in gelatin content of vaccines associated with reduction in reports of allergic reactions. Journal of allergy and clinical immunology, 106(3), 591-592.
18. Bogdanovic, J., Halsey, N. A., Wood, R. A., & Hamilton, R. G. (2009). Bovine and porcine gelatin sensitivity in milk and meat-sensitized children. The Journal of allergy and clinical immunology, 124(5), 1108.
19. Chung, E. H. (2014). Vaccine allergies. Clinical and Experimental Vaccine Research, 3(1), 50. doi:10.7774/cevr.2014.3.1.50 
20. Cabral, D. (2000). A guide to contraindications to childhood vaccinations. Canadian Journal of Infectious Diseases, 11.
21. Mantadakis, E., Farmaki, E., & Buchanan, G. R. (2010). Thrombocytopenic purpura after measles-mumps-rubella vaccination: a systematic review of the literature and guidance for management. The Journal of pediatrics, 156(4), 623-628.
22. Turner, P. J., Fleming, L., Saglani, S., Southern, J., Andrews, N. J., Miller, E., ... & Thomas, H. M. (2020). Safety of live attenuated influenza vaccine (LAIV) in children with moderate to severe asthma. Journal of Allergy and Clinical Immunology, 145(4), 1157-1164.
23. Turner, P. J., Southern, J., Andrews, N. J., Miller, E., Erlewyn-Lajeunesse, M., & SNIFFLE Study Investigators (2015). Safety of live attenuated influenza vaccine in atopic children with egg allergy. The Journal of allergy and clinical immunology, 136(2), 376–381. 
24. Armstrong PK, Dowse GK, Effler PV, Carcione D, Blyth CC, Richmond PC, Geelhoed GC, Mascaro F, Scully M, Weeramanthri TS. Epidemiological study of severe febrile reactions in young children in Western Australia caused by a 2010 trivalent inactivated influenza vaccine. BMJ Open. 2011;1:e000016.
25. Top, K. A., Brna, P., Ye, L., & Smith, B. (2018). Risk of seizures after immunization in children with epilepsy: a risk interval analysis. BMC Pediatrics, 18(1).
26. Ma, X., Does, M. B., Metayer, C., Russo, C., Wong, A., & Buffler, P. A. (2005). Vaccination history and risk of childhood leukaemia. International Journal of Epidemiology, 34(5), 1100–1109.
27. Moss, W. J., Clements, C. J., & Halsey, N. A. (2003). Immunization of children at risk of infection with human immunodeficiency virus. Bulletin of the World Health Organization, 81, 61-70.
28. Campbell, A. G. (1988). Immunisation for the immunosuppressed child. Archives of disease in childhood, 63(2), 113.
29. Ridgeway D, Wolff LJ. Active immunization of children with leukemia and other malignancies. Leuk Lymphoma. 1993;9:177–92.
30. Ljungman P. Immunization in the immunocompromised host. In: Plotkin SA, Orenstein WA, editors. Vaccines. 3rd edn. Philadelphia: WB Saunders Co; 1999. pp. 98–110.
31. Sung, L., Heurter, H., Zokvic, K. M., Ford-Jones, E. L., Weitzman, S. S., Freeman, R., … Scheifele, D. W. (2001). Practical vaccination guidelines for children with cancer. Paediatrics & Child Health, 6(6), 379–383.
32. Zabeida, A., Lebel, M. H., Renaud, C., Cloutier, M., & Robitaille, N. (2019). Reevaluating immunization delays after red blood cell transfusion. Transfusion, 59(9), 2806-2811.
33. Black, C., Kaye, J. A., & Jick, H. (2003). MMR vaccine and idiopathic thrombocytopaenic purpura. British journal of clinical pharmacology, 55(1), 107-111.

Figure

Test image