Vaccines guard you against serious diseases such as Hepatitis B, so do not overlook them by A/Prof Lim Poh Lian
The Straits Times (16 October 2018) - Thirty years ago, the 41st World Health Assembly committed the World Health Organisation to an audacious goal: eradicating polio by the year 2000.
The massive global polio eradication campaign worked to a great extent because there was a cheap, effective vaccine.
There were just 22 polio cases last year, down from 350,000 cases 30 years ago.
Polio could be the second human infectious disease to be eradicated in history, after smallpox.
As long as one person with an active polio infection remains on the face of the earth, polio could come roaring back, with its life-altering effects of paralysis.
We have come far in the global effort to eradicate polio, but the last stretch is often the hardest.
Nevertheless, vaccines have helped to save many lives and prevent disability. Yet, many people do not bother to get vaccinated against infectious diseases.
I am not just talking about vaccines against seasonal influenza, but those you can get to guard you against more serious diseases such as Hepatitis B, which can cause liver cancer, and human papillomavirus (HPV), which causes cervical cancer.
After all, if you could protect your child from getting cancer, wouldn’t you?
Vaccines to Prevent Cancer
The heartache of hearing about lives cut short by cancer or the suffering and pain associated with cancer as one grapples with the side effects of chemotherapy, radiation and surgery will make one try to spare one’s loved ones from all these.
And if you could prevent cancer with three simple shots, would you not do so? Most people would say yes.
The Hepatitis B vaccine was the first successful vaccine to bring down the number of people who were diagnosed with liver cancer.
The first Hepatitis B vaccine was licensed in 1981, but a decade later, only 1 per cent of the world’s population had been vaccinated against the disease.
Fortunately, by 2014, Hepatitis B vaccination had been implemented in 184 countries.
When infants get infected with Hepatitis B, up to 90 per cent of them become chronic carriers, compared with 5 to 10 per cent of those who get infected as adults. Importantly, by vaccinating everyone at birth against Hepatitis B, not only are they spared the infection and its complications, but they also will not be able to spread the disease to others.
Countries which have successfully implemented Hepatitis B vaccination have seen a whopping 60 to 80 per cent drop in acute and chronic infections.
Singapore is one of them. Whole generations will be spared the ordeal of suffering from liver cancer as a result of Hepatitis B.
Thankfully, we now also have another successful cancer vaccine, which is against cervical cancer. I still remember my first cervical cancer patient.
For the generations who saw people affected by polio, taking three to four doses of oral vaccine to prevent life-long
paralysis was a no-brainer...
For subsequent generations who have not seen polio, this brilliant medical breakthrough can feel like
an inconvenience or an imposition.
It was September 1991 and I was barely two months into my internship at a hospital in Boston.
Walking into her room to check on her, I was struck by how gracious she was, even as death loomed near. She was a doctor and only 34.
HPV causes cervical cancer in women and is spread through sexual contact. An estimated 266,000 women died of cancer in 2012.
The first HPV4 vaccine was licensed in the United States in 2006. It provided protection against the two virus strains that cause 70 per cent of cervical cancers as well as another two strains causing genital warts.
Then, in 2014, the US approved HPV9, which covered five additional cancer-causing strains.
This means that it can protect against 90 per cent of cervical cancer cases.
This vaccine was launched in Singapore last year, but the uptake here has remained low.
While people in Singapore stay away, foreigners have come for it.
We have seen women flying in from Beijing and Shanghai to get the HPV9 vaccine because it was not yet available in China.
The Power of Herd Immunity
Interestingly, when a vaccine is so effective that people do not see the disease and fear it, complacency can set in.
At the same Boston hospital where I was at, there was a 1992 case which brought home the importance of getting vaccinated.
A 60-year-old American man had returned from an overseas trip with a fever, cough, conjunctivitis and a runny nose. He looked miserable and his blood tests confirmed that he had measles.
Born in the generation before childhood vaccines became routine, he had managed to dodge the bullet... until then.
His care was presented at the hospital’s teaching grand rounds because all the resident doctors there had never seen a patient with measles before.
Fast-forward to today, measles has unfortunately made a resurgence in many countries and continues to be a problem in Singapore.
In 2016, there were 118 local cases of measles here, 45 of which happened in babies under a year old.
Vaccinations for measles, mumps and rubella are not given until a child is 12 months of age, so young infants in particular need the protection of herd immunity. So, we all have a part to play in getting vaccinated against key diseases.
We have a saying in public health: “An outbreak averted makes no headlines.”
For the generations who saw people affected by polio, taking three to four doses of oral vaccine to prevent life-long paralysis was a no-brainer.
My father contracted polio when he was four years old. He took years to regain strength in his legs and walked with a limp all his life.
For subsequent generations who have not seen polio, this brilliant medical breakthrough can feel like an inconvenience or an imposition.
Nevertheless, the bottom line is that vaccines work. They protect by getting our immune systems ready for specific organisms before the actual infection hits us.
If vaccine uptake is good enough, even those who are too young or too sick to be vaccinated can be protected through herd immunity.
We all care about our health and the recommendations of the health authorities and clinicians make a difference. So, let us work together to improve immunisation rates for the protection of all in our community and the world.