Addendum (25/05/2008): Have changed the compulsory and optional headings to recommended and enhanced regimes. Many thanks to angrydoctor for pointing it out.
While blog-surfing, J. was surprised to notice there’s a pretty vocal antivaccine movement in the West. “Antivaccine” because J. can’t figure out if they’re talking about thimerosal, symptoms suggestive of autistic spectrum disorder (ASD) in kids with mitochondrial disorders and whatnot except that ‘vaccines are bad, they cause autism’.
Anyway, J. thought he’d comment on a couple of things that people might have misconceptions about, and talk about what he’s learnt about the vaccination schedule in Singapore.
More information can be obtained on the National Immunisation Registry.
- Bacillus Calmette-Guerin (BCG:to prevent miliary tuberculosis) – At birth
- Hepatitis B – At birth, 1 month, 6 months
- Diphtheria, Pertussis, Tetanus – 3, 4, 5 months, booster at 18 months (diphteria, tetanus only) booster at 10-12 years
- Oral polio vaccine (Sabin) – 3, 4, 5 months, booster at 18 months, 6-7 years, 10-12 years
- Measles, Mumps, Rubella (MMR) – 15 months, booster at 6-7 years
- Haemophilus influenza type b (Hib) – 3, 4, 5 months
- Varicella zoster (chicken pox) – 15 months ( 13 years 2 doses)
- Pneumococcal vaccine – Prevnar less than 2 years, Pneumovax after 2 years
- Hepatitis A – non-schedule, 3 doses beginning at least 4 weeks before travel and um, if you really like half-cooked shellfish
- Meningococcus – Single dose tetravalent, especially for pilgrims going on the Haj
Now, onwards to questions!
People say that autism rates have gone up when vaccine rates have gone up! Does this mean I shouldn’t get my children vaccinated?!
Well, somewhat of a moot point since in Singapore the MMR and DPT/DT are legally required, but it’s not true! You see, correlation does not equate causation. Pirate counts have gone down and global temperatures have gone up! Coincidence… or… the lack of pirates causes global warming? Oil prices have gone up and infant mortality has come down! Coincidence… or… we should raise oil prices through the roof so less kids will die?
Also, there’s been no good studies at all that correlates vaccines with autism. However, there have been good studies to show that vaccines decrease childhood mortality and morbidity, have helped control diseases and are generally safe. In the light of existing evidence, please, vaccinate your child.
Polio has been eradicated, did my baby really need three doses of the polio vaccine before he was 18 months old?
Yes, yes he does. Poliomyelitis was eradicated because of a comprehensive vaccination program. Transmissable diseases usually have a number needed to treat (NNT) to stop prevention. The more highly transmissable, the higher the percentage of people required to be immune. As such, polio is controlled because almost everyone is vaccinated. There’s no reason to allow polio to have a resurgence in our community.
I understand that around 90% of kids vaccinated gain the immunity the first time they get a shot. Why am I not given the option of testing to see if he even needs more than one done of a vaccine?
That is not true either. The efficacy of vaccines like polio vaccine and DPT/PT require that the dosing be complete in order to get >90% immunisation. Certainly, certain vaccinations like varicella-zoster or meningococcus only require one dose.
The required vaccine schedule should be limited to highly transmissible, deadly public epidemic-type diseases like polio, not lifestyle diseases like Hep B or HPV, or childhood diseases like chickenpox that are largely harmless.
Well, in Singapore, Hepatitis B is endemic with vertical (mother-child) transmission being the most common mode of transmission. It’s an easily preventable disease (vaccination!) with a huge problem in the form of liver cirrhosis and liver cancer, of which it’s a more common cause than alcohol. HBV can be transmitted sexually or through blood which is why healthcare professionals in Singapore are all vaccinated (with boosters if the childhood dose is insufficient).
Human papillomavirus (HPV) is a sexually transmitted disease that is the main risk factor for cervical and anal cancer. The high-risk subtypes, at least, the rest cause warts. Note, however, that unless one is very confident that one’s child will never have sex in their lifetime, it’s good to have an option of vaccination. That said, in Singapore HPV vaccination has not caught on because the subtypes present in Singapore might not be almost all Types 16/18 (the ones being vaccinated against), it doesn’t absolve the need for Pap smears and it’s really, really expensive.
If J. had a choice, he’s rather have been immunised against varicella when he was younger instead of having to sleep in his cousin’s room (he had chicken pox) so that he could catch it young. There’s a condition called zoster, caused by reactivation of varicella-zoster virus, which presents with painful vesicles along a dermatomal distribution. This occurs in people who have gotten chicken pox before. Painful, and preventable.
Anyway, J. hopes this helps clear up some misconceptions about vaccination. That said, he’s only a lowly medical student and not some infectious diseases guru, so please, peruse the National Immunisation Registry for more information.