Addressing the concerns that trigger vaccine hesitancy

Vaccines are substances that teach our immune system to recognise and defend our body against harmful microorganisms without exposing us to the disease itself. — TNS

Humans are exposed to environments that have numerous microorganisms, some of which are harmless while others are harmful.

When a microorganism invades the human body, it is recognised as foreign by the body’s immune system, which then mounts a response to fight off the microorganism.

The immune system also remembers the microorganism.

This “memory” provides protection on the next occasion the microorganism invades the human body.

This protection is termed “immunity”.

Types of vaccines

Vaccines are substances that teach the human body’s immune system to recognise and defend itself against harmful microorganisms by producing antibodies.

There are currently vaccines against 20 life-threatening diseases.

There are various types of vaccines, which are:

• Live attenuated vaccines, which use a weakened form of the live microorganism.
• Inactivated vaccines, which use the dead microorganism.
• Subunit, recombinant, polysaccharide and conjugate vaccines, which all use specific parts of the microorganism like its protein, sugar or casing, among others.
• Toxoid vaccines, which use a harmful product (i.e. “toxoid”) of the microorganism.
• Viral vector vaccines, which use genetic material that instructs the human body to produce a protein of the microorganism.

   

  These vaccines also contain another harmless virus that functions to get the genetic material into human cells.

• mRNA vaccines use messenger ribonucleic acid, which instructs human cells to produce a protein or part of a protein of the microorganism.

Vaccines stimulate the body’s immune response, although the different types of vaccines work in different ways.

Every vaccine has ingredients that provide immunity, and keep it safe and effective.

Most vaccines do not contain mercury. 

However, multi-dose influenza vaccines and one type of tetanus-diphtheria (Td) vaccine do contain a small amount of thimerosal, a preservative that contains ethyl mercury, which does not cause mercury poisoning and is safe for use in vaccines.

Influenza and Td vaccines are also available without any thimerosal.

Vaccines are administered to children and/or adults as injections, solutions or sprays.

Benefits of vaccines

Vaccination is a safe, effective and cost-effective way of getting protection against harmful diseases before coming into contact with those diseases.

It protects the individual and the community.

Vaccines have been recognised as one of the greatest medical advances in human history.

They provide protection against more than 30 life-threatening diseases.

The World Health Organization (WHO) estimates that essential vaccines have saved at least 154 million lives in the past five decades, i.e. six lives a minute, every day, for fifty years. 

Vaccination against 14 diseases has directly contributed to reducing infant deaths by 40% globally.

These diseases are:

• Diphtheria
• Haemophilus influenzae type B
• Hepatitis B
• Japanese encephalitis
• Measles
• Meningitis A
• Pertussis (whooping cough)
• Invasive pneumococcal disease
• Polio
• Rotavirus
• Rubella
• Tetanus
• Tuberculosis, and
• Yellow fever.

The measles vaccine alone accounted for 60% of the lives saved.

The WHO also estimates that childhood vaccines alone save more than four million lives annually from life-threatening diseases like measles, meningitis, pneumonia, tetanus and poliomyelitis.

Side effects and adverse events

Although often used interchangeably, side effects are not the same as an adverse event (or reaction).

However, both are unintended consequences of vaccines.

The side effects of vaccines are predictable and usually disappear within a day or so.

They include soreness, swelling or redness at the injection site, and sometimes, fever, rash and aches.

Adverse events are more serious, or even life-threatening, reactions to vaccines.

However, they are rare.

These adverse events are categorised as:

• Vaccine product-related, where a vaccine component triggered the reaction
• Vaccine quality-related, where the reaction is related to the manufacturing process
• Immunisation error-related, where the reaction is due to inappropriate handling, prescription or administration of the vaccine
• Immunisation stress-related, where the reaction is related to fear of vaccination
• Coincidental, where the reaction has nothing to do with the vaccine or any of the above, but it occurs soon after vaccination, and so, may be attributed to it.

Regulators worldwide monitor adverse events following immunisation (AEFI), even after a vaccine has been licensed for use.

In Malaysia, this monitoring is carried out by the National Pharmaceutical Regulatory Agency (NPRA), which is part of the Health Ministry.

Doctors report all AEFI to the NPRA, which then investigates the incident to determine if it is caused by the vaccine.

Although the words “serious” and “severe” are often used interchangeably, they are not the same.

A serious adverse event or reaction is a term used by regulators to describe life-threatening events like death, hospitalisation (or prolonged hospitalisation), or persistent or significant disability or incapacity.

A severe reaction is a non-regulatory term, which includes serious reactions, but also other reactions, which, although severe, are rarely life-threatening and do not usually result in long-term problems.

Examples of these are allergic reactions and seizures.

Vaccine hesitancy

“Vaccine hesitancy” is a term used for the delay in acceptance, or refusal of, vaccination, despite the availability of vaccination services.

It is complex and context-specific, varying across time, place and vaccines.

It is impacted by factors like complacency, convenience and confidence, and aggravated by misinformation or disinformation from anti-vaxxers, particularly those in positions of authority.

It is disconcerting that a small number of doctors are vocal anti-vaxxers.

Although high levels of hesitancy results in low vaccine demand, low levels of hesitancy do not necessarily equate with high vaccine demand.

The WHO has a Vaccine Hesitancy Determinants Matrix that addresses the factors influencing the decision to accept, delay or reject some or all vaccines in three categories – i.e. contextual, individual and group – and vaccine/vaccination-specific influences.

To address vaccine hesitancy, it is vital to understand that the ambivalence of the majority of hesitant parents can be influenced by trusted healthcare personnel.

There may be concerns about the number of vaccines given simultaneously or fear of potential long-term adverse effects.

Furthermore, it has to be recognised that mistreatment and inconsistent healthcare access have contributed to distrust in some societal groups.

However, what all parents have in common is that they want to do the best for their children - this is the single most important factor to recognise in communications about vaccines.

The sine qua non in addressing vaccine hesitancy are effective communication strategies and the addressing of specific concerns.

Vaccine hesitancy can only be addressed by concerted efforts from the Health Ministry, healthcare facilities and healthcare personnel.

The use of effective communication strategies can help ensure better uptake of lifesaving vaccines.

Listening to parents’ concerns, motivational advice and debunking of unreliable or false information improve vaccine acceptance.

Clear explanations build trust when messages are aligned with parental values and social norms, thereby strengthening vaccine confidence.

Although some parents may not accept vaccines immediately, continuing dialogue and consistent messaging increase the probability of eventual acceptance.

ALSO READ: Should doctors accept unvaccinated kids in their clinics?

The WHO’s World Immunisation Week is commemorated from April 24 to 30 every year.

The campaign objectives are to:

• “Demonstrate it is humanly possible to have less disease and more life, if people – and their communities – protect themselves and their loved ones from vaccine-preventable diseases through immunisation. ​ 
• “Encourage governments to turn vaccines into vaccinations through strong immunisation programmes at local and national levels to deliver on the promise of immunisation for all”.​

To achieve these objectives, vaccine hesitancy has to be addressed vigorously and continuously.

The use of effective communication strategies can help ensure that more children and adults receive lifesaving vaccines, thereby protecting both individual and public health.

Dr Milton Lum is a past president of the Federation of Private Medical Practitioners Associations and the Malaysian Medical Association. For more information, email [e-mail]. The views expressed do not represent that of organisations that the writer is associated with. The information provided is for educational and communication purposes only, and it should not be construed as personal medical advice. Information published in this article is not intended to replace, supplant or augment a consultation with a health professional regarding the reader’s own medical care. The Star disclaims all responsibility for any losses, damage to property or personal injury suffered directly or indirectly from reliance on such information.