Why Is the Dengue Vaccine Needed? An Associate Professor Answers More Questions About the Vaccine

WORDS ASSOCIATE PROFESSOR DR VERNA LEE KAR MUN

FEATURED EXPERT
ASSOCIATE PROFESSOR DR VERNA LEE KAR MUN
Family Medicine Specialist
IMU Healthcare
WHY IS THE QDENGA VACCINE NECESSARY? WE ALREADY HAVE PREVENTIVE MEASURES SUCH AS FOGGING TO PREVENT THE AEDES MOSQUITO FROM BREEDING.

Fogging is effective in killing the Aedes mosquitoes. Its effect is immediate, extending to an average of 72 hours.

Fogging Works, but There Are Some Drawbacks

While fogging has been the main means to mitigate dengue infection in Malaysia, however, health offices are usually informed after the infection have been notified. As a result, fogging by itself does not reduce severe dengue infection that requires hospitalizations.

Furthermore, the resistance of the Aedes mosquitoes to insecticides is increasing. This decreases the effectiveness of fogging to control the population of these mosquitoes.

The Role of Dengue Vaccines

On the other hand, dengue vaccines have been proven to be effective in reducing the numbers of severe dengue infection requiring hospitalizations.

THERE WAS SOME CONTROVERSY WITH REGARDS TO THE SAFETY PROFILE OF THE PREVIOUS DENGUE VACCINE. SHOULD WE BE CONCERNED ABOUT THE QDENGA VACCINE?

Just like any new drug or new medical technology, there is very limited data from clinical practice in the early days. There would be many concerns.

Dengvaxia, the First Dengue Vaccine

The first dengue vaccine, Dengvaxia, was approved in April 2018.

It is safe in persons who have had dengue virus infection in the past (seropositive individuals), but it also increases the risk of severe dengue in those who experience their first natural dengue infection after receiving their vaccination (seronegative individuals).

Hence, pre-vaccination screening for past dengue infection is recommended before one receives the Dengvaxia vaccine. Only people with evidence of past dengue infection—indicated by the presence of dengue IgG antibody in their blood—would receive this vaccination.

About the Newest Vaccine, Qdenga

A second vaccine for dengue, Qdenga, received prequalification from the World Health Organization (WHO) on 10 May 2024.

Is it safe?

  • Overall, during the clinical trials, the vaccine was well tolerated. The most frequent reported vaccine-related adverse events were injection site itchiness, bruising, and fever.
  • An excess of hospitalized dengue virus serotype 3 (DENV3) infections was reported among baseline seronegative children, but it was not statistically significant.
  • There was also an excess of cases of severe dengue among seronegative vaccinees, all of which were caused by DENV3, but, again, the difference was not statistically significant.
  • An increase in the risk of dengue infection requiring hospitalization or severe dengue due to DENV3 in vaccinated seronegative subjects cannot be conclusively ruled out. We probably need to wait for more data.

How about allergy reactions?

During the clinical trial, no cases of severe allergy reaction or anaphylaxis were observed.

However, cases of anaphylaxis associated with this new vaccine occurred following the vaccine’s introduction to children between the age of 10 and 14 years in Brazil since February 2024, with 16 cases were reported (4.4/100,000 doses administered), including 3 cases of anaphylactic shock (0.8/100,000 doses administered).

The currently approved package insert for the vaccine describes precautionary measures to mitigate the risk of anaphylaxis. A full assessment of the national immunization programme is underway.

THE QDENGA VACCINE IS SAID TO BE ABLE TO IMMUNIZE AGAINST ALL FOUR SEROTYPES OF DENGUE VIRUS. WHY IS THIS A GOOD THING?

Dengue viruses belong to the genus Flavivirus.


The dengue virus. Click on the image for a larger, clearer version.


Flaviviruses are lipid-enveloped, single-stranded RNA viruses. The structural pre-membrane (prM) and envelope (E) proteins are embedded in the lipid envelope and are displayed on the surface of virions.

There are 4 dengue virus serotypes (DENV1, DENV2, DENV3, and DENV4); the serotypes share structural proteins (prM and E) but are genetically and serologically distinct.

Infection with 1 serotype induces sustained protection against the same serotype only. Although uncommon, an individual without a vaccine can be infected by each serotype for a total of 4 infections during their lifetime.

Serotypes and Infections

People who acquire a second dengue infection caused by a different serotype are at a higher risk for severe dengue once cross-protection induced by the first infection wanes.

Potential mechanisms for increased risk of severe dengue caused by a second infection include:

  • Cross-reactive antibodies binding to a different DENV serotype, which then enable uptake in inflammatory cells. This leads to higher and more prolonged virus count in the blood circulation (higher temperature and prolonged fever) that induces imbalanced pro-inflammatory and anti-inflammatory responses often referred to as antibody-dependent enhancement.
  • The action of the non-structural protein 1 (NS1) on the blood vessel wall or endothelium can trigger the release of active chemicals from immune cells.
  • Both the above will result in endothelial hyperpermeability and vascular leak (leading to hypovolemic shock and bleeding).

How the Vaccine Is Beneficial

Both dengue vaccines are tetravalent live-attenuated vaccines.

The new vaccine, Qdenga, induces a broad spectrum of immune responses which include:

  • Neutralizing antibodies with a 50% reduction against all 4 dengue virus serotypes.
  • Cross-reactive antibodies that block the activity of the NS1 protein.
  • Type-specific memory B cells to all four serotypes.

This means the vaccine can protect us from severe dengue infection by all the 4 serotypes. This is a good thing.

New Year, Healthier You? An Expert Shares a Health Screening Strategy to Help You Get Started

WORDS LIM TECK CHOON

FEATURED EXPERT
DR MURALITHARAN GANESALINGAM
Head of Department
Obstetrics and Gynaecology
School of Medicine
International Medical University (IMU)
FIRST, LET’S REFLECT: DO YOU NEED HEALTH SCREENING? 

Health screening benefits us, even when we believe and feel that we are healthy.

Dr Muralitharan Ganesalingam tells us: “The goal of screening tests is to detect changes in the body before they become unmanageable. In this way, you have the chance to modify your lifestyle and steer away from a particular illness.”

GO FOR HEALTH SCREENING FROM EARLY ADULTHOOD (SUCH AS WHEN YOU START WORKING) AND DO IT TWICE A YEAR AFTER YOU TURN 45

As Dr Murali puts it:

  • Generally, women between 19-24 years of age are considered to be at the peak of health.
  • From the age of 25, fat begins to accumulate, especially in the hips, thighs and abdomen, while muscle mass deteriorates.
  • From the age of 35, bone mass depletes at a rate of 0.5% to 1% each year.

There will be variations to this trend, as people are difference and hence their bodies age differently too. However, these changes with ageing prompt the recommendation given by Dr Murali, as health screening can help in detecting early the health issues that can arise alongside these changes.

Furthermore, health screening can be helpful in detecting the development of certain diseases that may not show obvious symptoms at the early stage.

PRIORITISE THESE HEALTH SCREENING TESTS
  • Blood pressure to check for hypertension. “This disease, known as the ‘silent killer’, progresses without noticeable symptoms and affects 3 in 10 Malaysians (approximately 6.4 million people), and increases the risk of stroke and heart attack,” explains Dr Murali.
  • Blood count to detect conditions like anaemia. On average, anaemia affects 3 in 10 women aged 15 to 49 years and can cause complications during pregnancy such as miscarriage and premature birth.
  • Blood glucose test to check for diabetes.
  • Body mass index (BMI) to monitor weight gain and help prevent obesity. Dr Murali points out that our national statistics show that 1 in 2 adults are overweight or obese, and 1 in 2 have abdominal obesity, of which women accounted for 54.7% and 64.8% respectively.
  • Lipids test to check for elevated levels of cholesterol, which can lead to heart disease. Around 4 in 10 Malaysians, approximately 8 million people, have raised cholesterol levels, with women being more likely to have higher levels than men. In spite of this, 1 in 4 people are unaware they have high cholesterol.
  • Kidney function and liver profile, as chronic kidney disease affects 1 in 7 Malaysians, and diabetes is a significant risk factor for this disease.

Dr Murali also recommends going for annual eye checks, hearing tests, and dental check-ups as we age.

Just for women
  • Pap smears to check for cervical cancer. “Because we have an efficient screening programme through the use of Pap smears, we have been able to reduce the incidence of cervical cancer substantially,” says Dr Murali. “It is the most significant advancement in the control of cancer, hence annual screening for cervical cancer is something I emphatically encourage.”
  • Breast examinations (see below) to check for breast cancer. Dr Murali points out that it is essential for all women to be disciplined about performing their own breast examinations as well as to go for an annual check by a doctor, who will advise if a mammogram is needed.
  • Bone mineral density scans to detect osteoporosis. Dr Murali explains that one’s bone mineral density decreases with age and the risk of fractures increases, hence postmenopausal women 50 years and older should be screened. “Women aged 65 years and older should be screened at least once a year, according to Malaysian guidelines,” he adds.

An overview of how to perform breast self-examination at home. Click on the image for a larger, clearer version. If you are unsure or you have concerns, you can consult your doctor for more information.


FINAL ADVICE

“It is important for you to speak to your regular doctor about any health concerns and discuss what health screenings may be beneficial for you, based on your age, lifestyle and family history,” Dr Murali emphasizes.

Ever Wondered Why Vaccines Still Need to Be Injected into Your Body? Get the Answer from a Paediatrician!

WORDS DR DATIN CLARENCE KAVETHA A/P S.S. DANIEL

FEATURED EXPERT
DR DATIN CLARENCE KAVETHA A/P S. S. DANIEL
Consultant Paediatrician, IMU Healthcare
and Lecturer, School of Medicine, International Medical University

Injections can be scary for both adults and children population in general. So why do we still do it?

WHY ARE THE MAJORITY OF VACCINES STILL GIVEN VIA INJECTIONS?

This is mainly because, by injecting directly into the muscle, the vaccines produce a good immune response and certainly provide adequate protection.

Many studies on needle-based vaccinations have demonstrated that these vaccines have good efficacy and high safety levels.

Furthermore, the World Health Organization (WHO) have set standards for vaccine administration, and needle-based vaccination is accepted by most countries and has become a standard practice.

INJECTIONS DON’T HAVE TO HURT (MUCH)!

There are certain vaccines that can be given into the skin instead of the muscle, hence they can be less painful.

This method uses a shorter and thinner needle, so it can also be less intimidating as well to some people.

ARE THERE ANY NEEDLE-FREE ALTERNATIVES TO RECEIVING VACCINES?

There are a few alternative vaccines that do not involve needles. All said, the choice of vaccine delivery still depends on the vaccine characteristics and the targeted disease.

Some needle-free alternatives include oral vaccines in the form of liquid or tablet for diseases like polio and cholera. However, some vaccines are not stable when given orally, mainly because the digestive enzymes in our stomach make it very challenging for most vaccines to work.

Nasal vaccines are also available for certain infections such as the flu—these vaccines are sprayed into the nose.

Having said all of these, I should point out that there is still ongoing research and development to produce alternative vaccine delivery methods that would be less painful and easier to administer.

SCARED OF NEEDLES? DON’T LET YOUR FEAR KEEP YOU FROM GETTING YOUR SHOTS
  • Bring a close friend or family member along with you.
  • Tell the staff that will administer the shot that you’re afraid of needles. Most of them will understand and do their best to soothe your anxiety.
  • Don’t look at the needle going into your arm. Distract yourself by looking at something else or chatting with the staff or your companion.
  •  If your nerves are getting the better of you, take deep breaths and slowly count to 10.

Curious about Traditional Chinese Medicine? Get the Details from an Expert

WORDS DR ONG SIEW SIEW

FEATURED EXPERT
DR ONG SIEW SIEW
Clinician-in-Charge and Senior Chinese Medicine Practitioner
Chinese Medicine Centre
IMU Healthcare
YES, TRADITIONAL CHINESE MEDICINE IS LEGITIMATE  

Traditional Chinese medicine, often abbreviated as TCM, is a legitimate practice recognized the Ministry of Health Malaysia.

Indeed, under the Traditional and Complementary Medicine (T&CM) Act 2016 [Act 775], the TCM industry is going through an important transition towards greater uniformity and credibility among the practitioner community and the services they offer.

TRADITIONAL CHINESE MEDICINE USES DIFFERENT PRINCIPLES FROM WESTERN MEDICINE

The foundation of traditional Chinese medicine is this belief that every person has a unique body constitution pattern, signifying the intricate equilibrium of opposing elements.

These opposing elements must co-exist harmoniously for a person to be in good health.

Traditional Chinese medicine aims to restore this equilibrium and regulate the body’s dynamic energy, which can be affected by various factors such as diet, stress, chronic illnesses, and more.

TRADITIONAL CHINESE MEDICINE PRACTITIONERS CAN HELP WITH MANY AILMENTS

For example, they can help to relieve chronic pain, support the immune system, improve sleep quality, and much more. Some practitioners also specialize in certain areas of health such as the heart, lungs, digestion or the reproductive system.

Two patients with a similar ailment may receive different therapies because each of them presents a unique imbalance that requires rectification.

As the treatment evolves and the patient’s constitution undergoes changes, the prescription and treatment may require modification. Therefore, it is highly advisable to maintain continuity of treatment with the same practitioner, who can closely monitor your progress.

WHILE THEY ARE FUNDAMENTALLY DIFFERENT, WESTERN & TRADITIONAL CHINESE MEDICINE CAN GO HAND IN HAND

This is as long as both parties are well-informed.

It’s essential to take any oral medications from the two disciplines at least 4 hours apart to minimize the risk of interactions.

In contrast, for external treatments such as acupuncture, cupping or moxibustion, the likelihood of unwanted interactions is minimal.

TRADITIONAL CHINESE MEDICINE IS NOT SPIRITUAL OR RELIGIOUS 

Many people of different backgrounds seek help from TCM practitioners.

Indeed, for your first visit, it will be similar to any other medical appointment. The practitioner will take note of your medical history and perform some diagnostic techniques to check the body’s constitution.

It can be helpful to bring along medical records such as blood test results and any imagings like scans or X-rays to provide more background.

You can also list out your medications and supplements and discuss your daily routines and lifestyle.

All this information will help the practitioner to understand more about you and your needs, so that an effective treatment plan can be formulated.

In this way, a TCM practitioner assesses a patient’s condition using traditional Chinese medicine diagnostic principles and utilizes a personalized combination of treatment methods. These are all grounded in scientific and non-spiritual principles to address any imbalances in the body.

ALWAYS LOOK FOR A REGISTERED TCM PRACTITIONER

From March 2024, all licensed TCM practitioners will be registered with the T&CM Council and issued an Annual Practising Certificate (APC). This will make it easy to verify the authenticity of a registered TCM practitioner.

Everything You Need to Know About Managing Disruptive Menopause Symptoms

WORDS LIM TECK CHOON

FEATURED EXPERT
PROFESSOR DR NAZIMAH IDRIS
Medical Director
IMU Healthcare

I’m still young. Should I be concerned about menopause at this point in time?
“We should speak to women long before they reach menopause, so that, when it happens, they are more prepared and less anxious about it,” says Professor Dr Nazimah Idris.

She adds: “Many women I see wish they had known earlier what they could have done to prepare themselves. As every woman will go through this experience, you should enter this life phase empowered with knowledge.”

What’s menopause, exactly?
According to Prof Dr Nazimah, menopause is when a woman’s ovaries stop producing eggs and she stops menstruating.

Medically, menopause is confirmed when a woman has not experienced menstruation after one year.

Generally, this takes place when a woman is between 45 and 55 years old.

About 5% of women worldwide, however, experience early menopause between the ages of 40 and 45.

It’s also possible to experience menopause after undergoing a hysterectomy, chemotherapy, and other medical procedures that can damage the ovaries and affect menstruation.

Common symptoms of menopause. Click on the image for a larger, clearer version.

Why do some women experience symptoms of menopause even when they are still menstruating?

Prof Dr Nazimah explains that this is likely because the woman is experiencing perimenopausal stage (often called perimenopause for short), which can occur even before a woman enters menopause.

This stage usually lasts 4 to 5 years.

“During this time, it is normal to have irregular menstruation that may include heavier bleeding as well as infrequent or skipped cycles,” she elaborates.

Perimenopause can occur due to changes in a woman’s endocrine system. These changes can cause a reduction in the levels of oestrogen, the female sex hormone.

Because of this reduction in levels, a woman may experience symptoms of menopause such as hot flashes, fluctuating emotional states, difficulty sleeping and vaginal dryness.

She may also experience forgetfulness, low energy levels and reduced libido which, combined with vaginal dryness, can lead to less interest in sex and intimacy.

Once the woman enters menopause, the symptoms can become more severe and last up to another 5 years.

That sounds uncomfortable. Can anything be done about it?

Prof Dr Nazimah admits that a woman going through perimenopause and later menopause may experience around 10 years of symptoms. “This is a long time to be coping with symptoms if they are disrupting your daily life.”

Hormone therapy can help to manage severe and disruptive symptoms.

Tell me more about hormone therapy. Does it work, and how does it work?

“Hormone therapy can be very helpful in relieving hot flashes and improving sleep quality, vaginal dryness and urinary incontinence, among others,” she says.

There are different types of hormone therapy: tablets, topical creams, vaginal ring, and more. Medications may also be prescribed when necessary, such as to reduce the risk of osteoporosis due to low levels of oestrogen in the body.

The doctor will recommend the most suitable option based on a woman’s needs, family history, and other factors.

This sounds intriguing. Is hormone therapy an option for every woman experiencing symptoms of menopause?

Well, for one thing, Prof Dr Nazimah points out that hormone therapy is generally well-tolerated.

Hence, it is an option available to most women even when they have chronic diseases such as type 2 diabetes and high blood pressure.

However, hormone therapy may not be suitable for women that have certain diseases and conditions such as breast cancer, liver disease, thromboembolism, and heart disease.

If you have a health condition and are interested in hormone therapy, Prof Dr Nazimah recommends consulting a doctor for more information.

FEATURED EXPERT
SIN YEN SUAN

Certified Chinese Medicine Practitioner
IMU Healthcare

How about natural remedies for menopause symptoms? Do they work?

According to Sin Yen Suan, a certified Chinese medical practitioner, natural remedies such as evening primrose and black cohosh are traditionally turned to for perimenopause and menopause.

However, research on the efficacy on these remedies has yet to uncover any conclusive evidence on their efficacy in relieving the symptoms of perimenopause and menopause.

“However, Chinese medicine may be able to help,” Yen Suan offers.

She explains that the effectiveness of Chinese medicine can be seen by about 3 cycles of treatment, although the whole treatment process for menopause symptoms may last 1 to 2 years.

How exactly can Chinese medicine help?

Yen Suan further elaborates that Chinese medicine treat health problems by addressing imbalances in the body through individualized therapies, based on each person’s health status, needs, and other factoers.

“Many women come to me for help with symptoms such as persistent or heavy vaginal bleeding especially, heavy sweating, hot flashes, and disturbed sleep,” she says. “To help, we use several different treatments such as herbal medications to balance their qi or acupuncture to stimulate blood flow at the meridian points. These methods help to ease their emotional state, so they are able to feel better and sleep better at night.”

Chinese medicine can complement a person’s current Western medicine regime. If you are considering Chinese medicine to complement your current medical treatments, she recommends keeping both your doctor and Chinese medicine practitioner updated on your current forms of treatment.

PROF DR NAZIMAH’S TO-DO CHECKLIST FOR WOMEN EXPERIENCING MENOPAUSE
  • Menopause is not the end of life as you know it. Embrace new experiences, learn new things, take up a new hobby, make new friendships and rekindle old ones—the list goes on and on.
  • Speak to your doctor about health screenings such as Pap smear, mammograms, and colonoscopy, which are useful in detecting early stages of cancer and other health issues.
  • Also consider tests such as blood tests for anaemia and diabetes as well as bone density scans for osteoporosis.
  • Women over 51 should increase their calcium intake to 1,200 mg a day and consume vitamin D3 to keep their bones healthy and reduce their risk of osteoporosis.
  • Do regular Kegel or pelvic floor exercises, weight bearing exercises, and strength training to keep your body in good working condition.
  • Quit unhealthy habits such as smoking.