Prof Zabidi Azhar Mohd Hussin, IMU Pro Vice-Chancellor, Academic with a special interest in Paediatric Neurology and Medical Education explains the importance of childhood immunisations against vaccine preventable diseases in conjunction with World Immunisation Week ( 24-30 April 2021).
Vaccines are deemed as one of the greatest scientific innovations in the history of modern medicine as they prevent 2-3 million deaths a year from serious diseases (World Health Organisation, 2021). In the past century, they have helped eradicate smallpox and brought us closer to ending many debilitating, life-threatening afflictions. Due to improved accessibility of vaccines, billions of people today live healthy lives protected from vaccine-preventable diseases like diphteria, measles, pertussis, tetanus, pneumococcal disease and hepatitis. “Immunisation is a simple and effective way of protecting children from serious diseases that are potentially harmful or even deadly. By immunising a child, you not only protect the individual, but also the broader community by minimising the spread of disease,” says Prof Zabidi Azhar Mohd Hussin, Pro Vice-Chancellor, Academic at the International Medical University (IMU) in Kuala Lumpur and Consultant Paediatrician, IMU Healthcare. Children are invariably exposed to pathogens through their daily interaction with family members, playmates and schoolmates. Immunisation therefore play an important role in strengthening their immunity and protection against serious illnesses. “Newborns naturally inherit their mother’s immunity in the first few months of life. However, this soon wanes. As babies have an under-developed immune system, they may be stricken with various infections four to eight times a year. While young children are generally able to fight off most infections, there may be some pathogens or virulent diseases that are beyond their immune system’s capability.” Essentially, vaccines work by triggering the immune system to fight against a particular disease. “They contain the same germ that causes a particular disease. But the germs in the vaccine have been killed or weakened so that they do not make your child sick,” explains Prof Zabidi.
|Presently, there are four (4) main types of vaccines:|
|Inactivated vaccines are made from a dead virus or bacterium;|
|Live-attenuated vaccines use a weakened version of a virus or bacterium;|
|Subunit, recombinant, polysaccharide, and conjugate vaccines take a structural component from a virus or bacterium that can train your immune system to attack that part of the germ; and|
|Toxoid vaccines derived from the toxins of a germ that makes you immune to its effects.|
In addition to these, scientists are working on recombinant vector vaccines which are good for teaching the immune system to fight germs and RNA-based vaccines for longer-lasting immunity. “When your child gets immunized, his/her body is tricked into thinking that it has been infected with the disease. It starts to manufacture antibodies that kill the germs. These antibodies stay in the body for a long time. So, if the child comes in contact with the disease, his/her immune system is able to respond more effectively, preventing the disease from developing or greatly reducing its severity,” he adds. Prof Zabidi highlights this in particular in his contributing chapter on “Vaccines and Children”, due to be published by Universiti Sains Malaysia, USM.
|Severity of Diseases|
|Measles can cause death due to inflammation in the lungs and other vital organs|
|Diphtheria incapacitates the nervous system and affects the heart with a death rate of up to 50%|
|Poliomyelitis, caused by Enterovirus C, is spread by faecal-oral transmission (taking food or water contaminated by stool of an infected person) and also by saliva droplets, that may result in muscle weakness and paralysis.|
|Mycobacterium Tuberculosis which causes Tuberculosis (TB) is ever-present in the air and community and causes serious complications and damage to the lungs and other vital organs.|
|Mumps caused by the Paramyxovirus may cause encephalitis and deafness|
|Pneumococcal infections, caused by the bacterium Streptococcus pneumoniae, can lead to pneumonia, septicaemia (blood poisoning), meningitis and possibly death.|
“The National Immunisation Programme (NIP), introduced by the Ministry of Health of Malaysia (MOH) since the 1950s to curb the spread of infectious diseases in the community currently administers free vaccinations to children that protect against 13 potentially harmful diseases,” says Prof Zabidi.
“They are Bacillus Calmette-Guerin (BCG), a vaccine that gives protection against tuberculosis; 6-in-1 vaccine which contains: diphtheria (D), tetanus (T), polio, pertussis, Hepatitis B and Haemophilus Influenza type B; MMR, the combination of Measles (M), Mumps (M) and Rubella (R), and HPV (Human Papillomavirus), a vaccine that protects against cervical cancer. For Sarawak only, there is an additional vaccine that fights against Japanese Encephalitis, JE.” “Children receive these vaccines within the first 18 months of their lives, except for the HPV vaccine which is given to teenage girls at 13 years of age.” Prof Zabidi says that since the NIP was introduced, cases of serious infectious diseases have decreased significantly; Malaysia was declared free from polio in the year 2000. However, there are lingering traces of measles, mumps and rubella detected in some pockets of society primarily in rural areas even in this present day as immunisation is not compulsory by law in Malaysia. “It is estimated that only 92% of Malaysians have immunity against rubella and we have not been able to eradicate mumps completely,” says Prof Zabidi. “There is still some work to be done in Malaysia in terms of public health awareness and education where immunisation is concerned.”
|Whilst many may laud the life-saving role of vaccines, there are many individuals and communities that treat them with suspicion. Prof Zabidi notes with some regret several worldwide incidents that have unfortunately tainted the good work and noble cause behind the creation of vaccines. He gave the example of a well-known controversy surrounding an article by Andrew Wakefield published in the renowned medical journal, The Lancet in 1998, which claimed that the MMR vaccine causes autism in children. Although the worldwide medical community denounced the article as spreading unnecessary fear in the community through unverified facts, and the article was subsequently retracted by The Lancet in 2010, the immediate fallout and damage it created was substantial. Not only did the article and controversy spawn the rise of the global anti-vaxxers movement in the late 1990s but the resulting number of children who subsequently became ill with measles and the sudden outbreaks of disease in communities in the United Kingdom and America also increased significantly. The unwillingness of parents to vaccinate their children greatly burdened the public health system of those countries. “Some parents have also raised concerns of the use of thimerosal, a mercury containing compound as a preservative for flu-vaccines. Rest assured, as reported by the Centers for Disease Control and Prevention (CDC), except for some flu vaccines in multi-dose vials (to safeguard against contamination of the vials), no other childhood vaccines contain thimerosal as a preservative. Reputable scientific studies have not found any evidence or association between thimerosal in vaccines and autism,” he says.|
Prof Zabidi reiterates that vaccines for children are safe with few side effects as they are developed after many years of research and have undergone numerous clinical trials. He encourages parents of young children to check with their nearest government clinic on their child’s immunisation schedule if they have not already done so.
“Many parents may have reservations in bringing their children to a clinic or hospital for fear of exposing them to Covid-19 in the current pandemic. However, vaccinations need to be timely to be effective. Do stick to the vaccination schedule whenever possible to ensure optimal protection for your child,” he says. “Observe current SOPs to keep yourself and your child safe.” Prof Zabidi hopes Malaysian parents will heed the call to immunise their children against potentially harmful diseases. “Immunisation is an important component of primary health care and a human right. The best gift you could give your child is a shot at a healthy start in life.” Article in Malay: Vaksin Rangsang Sistem Imun (Harian Metro, 28 June 2021).