Young girl with partial paralysis, caused by polio. (Courtesy Boston Children's Hospital)
Young girl with partial paralysis, caused by polio. (Courtesy Boston Children’s Hospital)

Take a hard look at the picture. These are images we don’t see in this country at all anymore. But until the polio vaccine came along in 1955, children and adults paralyzed from polio were fairly commonplace. (FDR, anyone?) Today, vaccines are now a victim of their own success. Because they’ve so successfully wiped out devastating childhood illnesses, people seem not to fear those illnesses anymore. Now we have parents who decide not to have their children vaccinated.

As KQED News has reported this week, the number of parents in Marin County opting out of vaccines for their children is climbing. Last year, 7.8 percent of Marin parents opted out, 1 percentage point higher than the previous year. At present, California has one of the most lenient laws in the country to allow parents to decline vaccinating their kids: the “personal belief exemption.” It’s a short statement that says vaccinations are against a parent’s beliefs. (A new law amends this exemption somewhat; more on that below.)

On Thursday, KQED’s Forum took up the question of vaccines, and it was clear that many people remain confused on some key points.

1. What is herd immunity?

This simply means that enough people are vaccinated against a contagious illness that most of the community is protected — including those who cannot be vaccinated, such as newborn infants and people with compromised immune systems. And there are a lot of people with compromised immune systems, including pregnant women, people being treated for cancer, HIV/AIDS patients and more. The percentage of people who need to be vaccinated to create herd immunity for many childhood illnesses is high — 90 percent, according to the federal government’s Healthy People 2020 goals. The National Network for Immunization Information draws a striking contrast between two outbreaks of measles. In 2003, an infected Japanese tourist arrived in the Marshall Islands, where vaccination rates were below 75 percent (i.e., below a herd immunity level). An epidemic ensued with more than 700 cases, 56 hospitalizations and three deaths. In the same year, there were two separate introductions of measles in Mexico. But vaccination rates were above 95 percent there. Only 41 people contracted measles as a result. Vaccination matters.

2. Does state law require kids to be vaccinated? And can I find out how many kids are not vaccinated at my child’s school?

The short answer is “yes” to both questions. State law requires that children at all public and private schools be fully immunized before they start kindergarten. The California Department of Public Health sets the list of vaccines, but essentially follows national guidelines from the federal government and the American Academy of Pediatrics. A very small number of children cannot be vaccinated for medical reasons, and they are eligible for a “personal medical exemption.” But in California, the bigger problem has been the personal belief exemption, or PBE. This is the last school year that parents will be able to avoid vaccination for their children simply by signing a piece of paper saying they are opposed to vaccines. Starting in January, when a new state law goes into effect, parents will also need to provide a signed form from a health care provider who will have explained the benefits and risks of vaccines as well as the risks of communicable diseases. While it’s plausible this law won’t make a difference to the dedicated anti-vaccine crowd, it may well make a difference to people who have found conflicting or inaccurate information on the Internet or other sources (or parents who find it easier to drop off a signed statement instead of vaccinating their kids). The state of Washington passed a similar law in 2011 and their opt-out rate has dropped by almost 40 percent. Here in California, the state compiles data on vaccination rates for public and private schools statewide, and you can look up your own child’s school.

3. I disagree with the vaccination schedule and have developed my own. Is this a problem?

The CDC’s Advisory Committee on Immunization Practices reviews the vaccine schedule every year. What many people don’t know is that there is some flexibility built into the schedule. For example, the third dose of the hepatitis B vaccine can be given between 6 and 18 months of age. The third dose of polio can be given between 4 and 18 months. If you adjust the schedule on your own, you are putting your child at risk of developing a serious illness that could have been avoided. CDC information allays concerns about vaccines overloading a child’s immune system:

Every day, a healthy baby’s immune system successfully fights off millions of antigens—the parts of germs that cause the body’s immune system to go to work. …

Vaccines contain only a tiny fraction of the antigens that babies encounter every day in their environment, even if they receive several vaccines on one day.

4. If your child is vaccinated, why do you care if mine is not?

While vaccines are highly effective, they are not 100 percent effective. This goes back to herd immunity described above. In order to protect the entire community, we need for as many people to be vaccinated as possible. Again, it’s not just about protecting children. People who deny vaccinations to their children put pregnant women, cancer patients, AIDS patients and even healthy people at risk of disease. Here’s just one example about one of the “newer” vaccines, against Haemophilus Influenzae type b, also known as Hib. Before 1985 — before the vaccine —  Hib caused serious infections in children, including 12,000 cases of meningitis and 7,500 cases of pneumonia. Compare that with 2002, when there were just 34 cases of Hib disease.

5. What about the link to autism? Or other problems from vaccines?

The public confusion about a connection between vaccines and autism stems primarily from one major study. In 1998, the Lancet published a study from British researchers which implicated the measles, mumps and rubella vaccine as increasing the risk of autism. There’s just one problem: One of the researchers on that study, Dr. Andrew Wakefield, was investigated. Britain’s General Medical Council concluded his “conduct was irresponsible and dishonest,” and the study was later retracted. But Wakefield’s damage is hard to undo. The concern continues to circulate.

As for other side effects of vaccines, yes, they exist. Like everything else in life, vaccines, too, come with risks of adverse effects. The risks are small, but not zero. The CDC and the FDA co-sponsor a reporting system to track vaccine side effects.

Now, back to polio for a minute. If you really want to feel the fear of life before the polio vaccine, watch this excellent segment from RLTV’s documentary Polio Revisited. It will break your heart.

This post has been updated to clarify the role of the Lancet study in the public confusion around vaccines and autism.

5 Things You Should Know About Vaccines 19 February,2014Lisa Aliferis

  • Tony Floyd

    A concise and plain English summary. Thank you.

  • Jane006

    Wonderfully clear explanation and poignant photo.

  • Liz Ditz

    Thanks for taking the time to read all the counter-factual messages and distilling them down into this clear, concise summary.

    • Jenniffer

      What a hilarious comment. Lisa pretty much fibbed from start to finish in her opinion piece. Which is why it can only be taken for what it is: her opinion.

    • Liz Ditz

      Jenniffer alleges that Lisa Aliferis’s summary is factually wrong at least 5 times, but does not offer any actual charges, or proof that Aliferis is mistaken.. Therefore, Jenniffer’s comment is just so much piffle.

  • ameng
  • gw

    I dislike these one sided reports that use fear to bring the point to the public. Only three sentences about the other side of vaccines. California follows Federal Government, who also allows poison into our food (GMO) and onto our food for a profit. All the poison in our food and vaccines is ENOUGH already.

  • MK

    As a biologist and the daughter of a polio survivor, I’m relieved to see that the school my daughter will attend in a few years has a 100% vaccination rate. My baby is getting her shots on schedule, because I know way too much about the diseases those vaccines prevent.

  • Jens_disqussion

    Paralytic polio was a serious condition that without full explanation increased in incidence in the first half of the 20th century until in epidemic years it afflicted 1 in 2700 with 15% of cases sustaining longterm paralysis. Some iatrogenic causes, such as tonsillectomy and pesticide use, may have been involved in this increase so it is unclear what role vaccination alone has played in the apparent decrease in polio paralysis.

    After unprecedented liability protection for vaccine manufacturers in 1986, the U.S. infant vaccine schedule increased to approximately three times the schedule that was driving manufacturers out of the business. We have officially without explanation 1 in 50 with autism, 1 in 6 with learning disability or developmental delay, allergies, asthma, autoimmune conditions have all increased, and authorities will not perform the most basic vaccine safety research, comparing the health of never-vaccinated populations (a true control group needed for valid scientific claims of safety) with fully vaccinated groups to begin to calculate vaccine risks. Six month old infants now receive more vaccines than most adults did by college with no study of the overall costs of such repeated immune stimulation with doses of some vaccine components, such as Hg in the 1990s and Al today, well exceeding exposure guidelines. Currently many countries vaccinate less with better infant and childhood mortality outcomes.

    • Epinephrine

      You’re misinformed. The vaccination program for polio eradication going on worldwide shows the effectiveness of polio vaccination.
      We have plenty of explanations for increases in autism rates, like the fact that when the definition changed, suddenly there were more cases. Hg exposure was never above “exposure guidelines,” as any guidelines weren’t describing thimerosal, but other forms of mercury.

      • Jens_disqussion

        Actually in India, they have been giving more than a dozen doses to some trying to eradicate polio. And in 2011 they had 47,000 case increase of non-polio acute flaccid paralysis which has the same symptoms of polio but is caused by the oral vaccine so it is dubbed something else and has higher mortality risk.

        True, they had no guidelines for safe bolus dose exposure to ethylmercury. They still don’t. They were using oral methylmercury guidelines and at the two-month well-baby visit, exceeded the EPA daily exposure limit by 125 times. Research by Burbacher showed this guideline is not adequate as thimerosal deposited more inorganic mercury in brain tissue than oral methylmercury.

        Today, depending upon vaccines used a two-month-old now may receive up to a thousand times exposure limits for Al-based adjuvant.

        • White_and_Nerdy

          The government of India are kind enough to be very
          clear about acute flaccid paralysis.

          Clearly your assertion that these cases being caused by the polio vaccine are obviously untrue.

          Similarly your assertions about mercury/aluminum exposure
          are obvious calculation errors…they have been corrected countless times since the late 1990s.

          And you have completely misrepresented Burbacher’s findings. He showed that methyl mercury is a poor
          standard for thimerosal because thimerosal is safer.

          But then one of the points is that the vaccine critics are marginalized to posting on the Net because they get pretty much everything wrong….no matter how many times over how many decades their errors are corrected…


          • Jens_disqussion

            From Burbacher’s discussion section:

            The large difference in the blood Hg half-life compared with the brain half-life for the thimerosal-exposed monkeys (6.9 days vs. 24 days) indicates that blood Hg may not be a good indicator of risk of adverse effects on the brain, particularly under conditions of rapidly changing blood levels such as those observed after vaccinations. The blood
            concentrations of the thimerosal-exposed monkeys in the present study are within the range of those reported for human infants after vaccination (Stajich et al. 2000). Data from the present study support the prediction that, although
            little accumulation of Hg in the blood occurs over time with repeated vaccinations, accumulation of Hg in the brain of infants will occur. Thus, conclusion regarding the safety of thimerosal drawn from blood Hg clearance data in human infants receiving vaccines may not be valid, given the significantly slower half-life of Hg in the brain as observed
            in the infant macaques.

          • White_and_Nerdy


            When provided the actual data from India you are suddenly silent on the topic.

            OK, Burbacher is a fine topic.

            Here is the full-text version of the paper:

            You should note that by sentence 2 it is clear that your
            assertions about exceeding mercury guidelines by 125 fold is not true….a topic which you also are suddenly silent on….

            What was the paper’s conclusion?

            ” The key findings of the present study are the differences in the disposition kinetics and demethylation rates of thimerosal and MeHg. Consequently, MeHg is not a suitable reference for risk assessment from exposure to thimerosal-derived Hg.”

            This is very, very clear: methyl mercury is the wrong standard for assessing risk from ethyl mercury derived from thimerosal.

            What was the data?

            1. Half-life of EtHg in blood was shorter than MeHg because EtHg is excreted faster–this makes EtHg less risky then MeHg.

            2. The total brain Hg levels were 3-4 fold LOWER with EtHg vs. MeHg– this makes EtHg less risky then MeHg.

            3. Total brain mercury was cleared much faster from EtHg relative to MeHg– this makes EtHg less risky then MeHg.

            4. In addition to having less brain mercury, a higher percentage of the EtHg in the brain was converted to inorganic mercury relative to MeHg. As explained in detail in the discussion section, this process of converted EtHg to inorganic mercury is “… a detoxification process that helps to protect the central nervous system.”– this makes EtHg less risky then MeHg.

            This paper is very clear. And the simple fact is that the vaccine critics are not truthful about it.

            There is a huge amount written by the vaccine critics about the toxicity of thimerosal.

            I bet you can’t provide one example where they get the most basic facts correct.

            I bet you can’t provide one example where a vaccine critic though our children’s health was important enough to get their toxicology from an actual, qualified toxicologist.

            The conclusion is obvious.

          • White_and_Nerdy

            The Sounds of Silence……


  • Jake R.

    How about the HPV vaccine (which seems to be getting pushed by a wierd alliance of sexual revolutionaries, the government, and pharmaceutical companies)?

  • Dorit Reiss

    Thank you for providing this clear, concise information.

  • Amber

    FYI this article contains a lot of inaccurate information. I have done A LOT of research on vaccines and this article is garbage! Dr. Wakefield has been demonized and the journalist who tried to debunk him was investigated and it was confirmed that he had no medical background to verify his accusations against Dr. Wakefield. Vaccines are poison and should never be given to children. Just remember that the pharma companies are very rich and use fear to pump you full of poison! If you think they care about your health over profits you are sadly mistaken!

  • Pingback: Rise In Measles Cases Marks A ‘Wake-Up Call’ For U.S. : Shots | Office New()

  • Pingback: Rise In Measles Cases Marks A 'Wake-Up Call' For U.S. : Shots -


Lisa Aliferis

Lisa Aliferis is the founding editor of KQED’s State of Health blog. Since 2011, she’s been writing and editing stories for the site. Before taking up blogging, she toiled for many years (more than we can count) producing health stories for television, including Dateline NBC and San Francisco’s CBS affiliate, KPIX-TV. She also wrote up a handy guide to the Affordable Care Act, especially for Californians. Her work has been honored for many awards. Most recently she was a finalist for “Best Topical Reporting” from the Online News Association. You can follow her on Twitter: @laliferis

State of Health Sponsored by

Become a KQED sponsor