“In recent years, 13 Victorians have been hospitalized with measles despite having one or two vaccinations that should have made them immune. Why? Well, experts believe that because measles is so rare in Australia, we pretty much never come into contact with it, so our immune systems are starting to let their guards down and wane a little bit.”
Nathan Templeton on Measles Immunity Concerns
What is he talking about?
It’s the idea of exogenous boosting from being around natural infections. In other words, after you become immune from being vaccinated, you could get a boost in your immune protection if you are around someone with the disease.
“The exogenous boosting (EB) hypothesis posits that cell-mediated immunity is boosted for individuals reexposed to varicella-zoster virus (VZV).”
Talbird et al on Understanding the role of exogenous boosting in modeling varicella vaccination.
While this is thought to happen with chickenpox, we aren’t sure if it happens with measles.
It might, but the “problem” is that it is known that folks can have an amnestic response, so can be immune even though they have low antibody levels.
Mostly though, it is important to keep in mind that most of the people who get measles are unvaccinated, often intentionally unvaccinated.
“The key to measles elimination is increasing vaccination coverage and monitoring of measles antibody status for all ages, as well as enhancing surveillance of both domestic and overseas incidences.”
Inaida et al on Measles elimination and immunisation: national surveillance trends in Japan, 2008-2015.
So how many vaccinated Australians are getting measles?
“In Australia, the majority of measles cases are due to unvaccinated individuals becoming infected while travelling to countries in which measles is either common or there are outbreaks occurring. As measles is highly contagious, these people can then spread the disease to others, causing outbreaks, often before they are aware that they have the virus.”
Australia’s Measles Outbreaks 2019
And just as in the United States and most other countries, most of their outbreaks are started by folks who are unvaccinated.
So their immunization schedule is right for their country, even if it doesn’t match the United States schedule.
Australia’s Vaccine Schedule
In Australia, for example, the National Immunisation Program (NIP) Schedule is set by National Immunisation Committee (NIC), which reports to the Australian Health Protection Principal Committee (AHPPC) of the Australian Health Ministers Advisory Council (AHMAC) through the Communicable Diseases Network Australia (CDNA).
Notice any differences between Australia’s vaccine schedule and the US schedule?
they give the routine second dose of MMR earlier, at 18 months
they don’t give a second dose of the chickenpox vaccine
they give the routine first dose of the meningococcal vaccine earlier, at 12 months
the hepatitis A and flu vaccines are only given to high risk kids
While there are some minor differences, it is fairly similar to the US immunization schedule.
“There is a legislative requirement for all vaccines provided under the NIP or the PBS to undergo a thorough and objective assessment process.”
National Immunisation Strategy for Australia
Why the earlier dose of meningococcal vaccine?
This is a good example of why immunization schedules vary between countries.
“The notification rate for meningococcal disease to the National Notifiable Diseases Surveillance System peaked at 4.3 per 100 000 in 2002 and declined to 0.4 per 100 000 in 2013.”
Meningococcal disease incidence rates in the United States were much lower, about 0.6 per 100,000, when they started giving meningococcal vaccines in Australia (2001).
The UK Vaccine Schedule
But aren’t the immunization schedules from other countries supposed to be a lot different from the US schedule?
Let’s look at another…
It’s not the easiest schedule to read, but you should notice that vaccines for hepatitis A and chickenpox are missing, but younger children get extra meningococcal shots.
You may also have noticed yet another dosage schedule for the Prevnar 13 vaccine.
While the United States gives a three dose primary series and a booster, many other countries give either a three dose primary series alone or a two dose primary series with a booster.
“A large and growing body of evidence from immunogenicity studies, as well as clinical trials and observational studies of carriage, pneumonia and invasive disease, has been systematically reviewed; these data indicate that schedules of 3 or 4 doses all work well, and that the differences between these regimens are subtle, especially in a mature program in which coverage is high and indirect (herd) effects help enhance protection provided directly by a vaccine schedule.”
Whitney et al on Dosing schedules for pneumococcal conjugate vaccine: considerations for policy makers.
That doesn’t mean that they are all guessing at the dose! All of these schedules are well studied and in this case, there isn’t much difference.
There are even studies that suggest giving only one primary dose, combined with one booster dose might work, but only in areas where pneumococcal disease is already well controlled and infants would be protected by indirect herd immunity.
But that doesn’t mean that other schedules would work just as well too. For example, giving the doses later or on a slower schedule would not be better.
Infants are most at risk for many of these diseases, especially Hib and pneumococcal disease, when they are young and delaying when infants get vaccinated simply leaves them unprotected and at risk to get sick for a longer period of time. You also want infants to be protected by the time they lose the passive protection they get from their maternal antibodies.
What about the chickenpox vaccine?
While the UK has not added the chickenpox vaccine to their schedule because their models predicted an increase in cases of shingles (which has happened anyway) with a decrease in exogenous boosting (the theory that exposure to chickenpox lowers your risk of shingles), they are now looking at this again.
“This study confirms that severe complications of varicella, including death, continue to occur in the UK and Ireland.”
Cameron et al on Severe complications of chickenpox in hospitalised children in the UK and Ireland
Mostly it has been said that the chickenpox vaccine isn’t on the schedule because they have not thought it to be cost effective.
Iceland’s Vaccine Schedule
When anti-vaccine folks talk about immunization schedules from other countries, they aren’t usually talking about the UK or Australia though.
They are talking about Iceland, the country that they believe gives far fewer vaccines than the United States.
Vaccines for flu, chickenpox, hepatitis A, and hepatitis B and also available for those who are considered high risk.
Want to follow Iceland’s immunization schedule?
Then you should move to Iceland.
Hopefully you are starting to see that immunization schedules are different in each country because each country has different rates of disease, different populations, and different healthcare systems.
Iceland is a small country (338,349 people), with high vaccination rates, and universal health care. Compare that to the United States, with 327,200,000 people, clusters of unvaccinated people, and lots of people without health care.
It should be easy to see that what works in one country might not work in the other…
Vaccine Schedule Comparison by Country
What about other countries?
On the immunization schedule in Austria, the columns in red are for vaccines that are recommended and free. The blue columns are also recommended, but they aren’t free.
Japan has two separate schedules – the routine schedule for everyone (in dark blue above) and the voluntary schedule, with extra vaccines. Note that the primary series of infant vaccines are given at 2, 3, and 4 months.
Germany also gives their primary series of infant vaccines at 2, 3, and 4 months.
Although they only use a two dose primary series, Switzerland gives many of the same vaccines as the United States.
Are you surprised to see that infants in Holland get more vaccines before they turn 12 month old than infants in the United States and an extra set by four months?
Even if they aren’t routine in other countries, all of the same vaccines that are offered in the United States, including vaccines to protect kids against rotavirus, chickenpox, and hepatitis A, are available in most other countries.
The latest immunization schedule in Israel includes hepatitis B, DTaP, polio, pneumococcal, rotavirus, MMR, chickenpox, HPV, and flu vaccines.
What’s missing in South Korea’s immunization schedule? Meningococcal vaccines. But they do have some that we don’t give in the United States.
What’s missing in Denmark?
Folks who don’t vaccinate their kids!
Denmark has very high immunization rates – over 97% for infants and toddlers!
What don’t these different immunization schedules influence?
Prevalence rates of autism, SIDS, and other things that scare parents away from vaccinating and protecting their kids.
The One Wrong Way to Give Vaccines
Since the immunization schedules from all of these countries are just a little bit different, does that support the idea that an individualized approach to vaccinating kids is a good idea?
Of course not!
In many countries, even if they are missing protection against a few diseases that we routinely vaccinate against in the United States, many get their vaccines earlier! And all start by three months and don’t split up the schedule to just give one or two vaccines at a time.
Everyone knows that later and slower just leaves kids unprotected for longer periods of time. More risks. No extra benefits.