Monthly Archives: May 2019

Debunking Ten Arguments from the Anti-Vaccine Movement

Author of Staying Healthy Abroad, Dr. Christopher Sanford debunks ten common arguments used by anti-vaccine activists.

The purpose of this article is educational. For medical advice for any health condition, please consult your physician. To learn more about the measles outbreak, read this recent blog post.


In January of this year the WHO (World Health Organization) released a list, “Ten Threats to Global Health in 2019.” One of the ten threats listed was vaccine hesitancy: “the reluctance or refusal to vaccinate despite the availability of vaccines.”

For a variety of reasons, a significant number of people choose to forego vaccines for themselves and/or their children. Anti-vaccine sentiment has swelled in recent years to a vehement political movement, and declining vaccine rates have led to a resurgence of a number of infectious diseases. Measles has seen a 30% increase in global cases in recent years. There are now measles outbreaks in 22 US states.

The evidence for the benefit and safety of vaccines is voluminous and consistent. Dr. William H. Foege, a public health physician who was instrumental in the global eradication of smallpox, wrote, “Vaccines are the tugboats of preventive health.”

There are myriad arguments used by anti-vaccine activists. Below are ten common arguments that arise.

  1. Vaccines don’t work.
  2. Vaccines only give partial protection.
  3. Protection from vaccines is inferior to that from natural infection.
  4. Vaccines contain mercury, a toxic heavy metal, and antifreeze, ether, and other toxic chemicals.
  5. Vaccines cause autism.
  6. Vaccines are no longer necessary.
  7. Vaccines overwhelm the body’s immune system.
  8. Vaccines are a plot by pharma (large pharmaceutical corporations) to generate profit.
  9. Vaccines are a plot by the CDC and/or US federal government, to attain any of a panoply of nefarious goals.
  10. Vaccines contain fetal cells.

Let’s address these one by one.

1. Vaccines don’t work.

This is a bizarre argument. Disease after disease has diminished markedly in prevalence immediately following the introduction of its respective vaccine. Tetanus in the US has been reduced by more than 98%; polio is almost eliminated worldwide; smallpox, which caused an average 48,000 cases per year in the United States during the 20th century, has been eliminated from the planet. The HPV (human papilloma virus) vaccine was introduced in the US in 2006; already we are seeing a significantly reduced level of cervical cancer in women. The incidence of multiple other infectious diseases, including mumps, rubella, and pertussis, have been markedly reduced in recent years—all because of vaccination.

2. Vaccines only give partial protection.

This is true but is not a reason to avoid vaccines. And often the protection level is very high. At one extreme, vaccines such as yellow fever and hepatitis A (in those under age 40) offer over 99% protection. At the other extreme, influenza often offers about 50% protection; this can be even lower if the vaccine and circulating strains are a poor match. Many vaccines are about 90% protective. If vaccine levels are sufficiently high as to prevent easy transmission in a population (“herd immunity”), there may be sporadic cases but outbreaks are effectively prevented. The level of immunity necessary to attain herd immunity differs for different infections. For polio, this level is 80% of the population; for measles, which is more infectious, about 95% of a population needs to be protected, either by vaccine or prior infection, to prevent outbreaks.

3. Protection from vaccines is inferior to that from natural infection.

Untrue! Protection from either is equally protective. Vaccines provide protection without causing illness, or exposing people to the risk of death from their respective diseases.

4. Vaccines contain mercury, a toxic heavy metal, and aluminum, antifreeze, ether, and other toxic chemicals.

Thimerosol, a preservative which contains ethyl mercury, has been removed from all vaccines except multi-dose vials of influenza vaccine. There are thimerosol-free preparations of flu vaccine.

And thimerosol is not harmful. Ethyl mercury is quickly excreted from the body; it does not bioaccumulate. The form of mercury that bioaccumulates is methyl mercury; this is the form that is found is some seafood, such as tuna. Thus if you eat vast amounts of tuna, mercury toxicity may be an issue.

No vaccine contains ether or antifreeze. These are bizarre, invented assertions. Vaccines do contain miniscule amounts of aluminum, but this is without any health consequence. Melody Butler, founder of Nurses Who Vaccinate, correctly notes that a baby gets more aluminum from breast milk than from vaccines.

5. Vaccines cause autism.

Dr. William Wakefield, a British physician, published a single report in Lancet in 1996 stating that there is a possible link between the measles vaccine and autism. His report has since been retracted by Lancet; his license to practice medicine in the UK was subsequently revoked by the General Medical Council (GMC).

Every study—and there have been at least twelve—on the measles vaccine and autism show that there is no relationship between the two. The most recent study on this is a large one, on over 650,000 children in Denmark, published this year in Annals of Internal Medicine. It found that “…MMR vaccination does not increase the risk for autism, does not trigger autism in susceptible children, and is not associated with clustering of autism cases after vaccination.”

We do not know what causes autism, but we do know that it is unrelated to vaccines.

6. Vaccines are no longer necessary.

Au contraire. The only disease that has been eradicated from the planet is smallpox. All other infectious disease are still circulating, some common, some rare. All vaccine-preventable illnesses will become more common if vaccination rates drop.

7. Vaccines overwhelm the body’s immune system.

Not true. The human immune system can deal with hundreds of thousands of antigens (foreign substances that stimulate an immune response.) Whether one, or eight, vaccines are given on a single day, the immune response is equally strong to each.

8. Vaccines are a plot by pharma to generate profit.

Pharma—pharmaceutical corporations—making a profit on vaccines does not prove that vaccines are harmful. If all this were driven by pharma, it is unlikely that they would convince physicians, the CDC, public health officials, etc.

9. Vaccines are a plot by the CDC and/or US federal government, to attain any of a panoply of nefarious goals.

It takes a more paranoid mind than mine to think that the 15,000 people who work for the CDC are plotting to do you harm. The idea that that many health professionals would conspire to harm the American public—and that that doctors, nurses, etc., would be complicit—is preposterous.

10. Vaccines contain fetal cells.

A few vaccines (specifically: varicella [chickenpox], rubella [the R in MMR], hepatitis A, the older shingles vaccine [Zostavax, not Shingrix], and one preparation of rabies vaccine [Sanofi-Pasteur’s Imovax]) are made by growing the viruses, which are attenuated (non-disease causing) in fetal embryo fibroblast cells. These fibroblast cells were obtained from two elective terminations of pregnancies in the early 1960s, and continue to grow in laboratories today. No additional sources of fetal cells are needed to make these vaccines.


This is an emotional topic for many. Ethan Linderberger was raised in an Ohio family that did not believe in vaccines. When he recently turned eighteen, he decided to receive all recommended vaccines. His mother, Jill Wheeler, described this decision as “insulting” and a “slap in the face.”

With respect to infectious diseases, there is no zero-risk option. Your choices are the smaller risk from vaccines, or markedly larger risk from infectious diseases.

The bottom line is that the evidence for the benefits of vaccine is massive and consistent.

I concur with Jackson County (OR) Health Officer Jim Shames, who states, “From a medical standpoint, vaccines are probably the most powerful and effective public health intervention of all time.”

Given the vehemence and organization of anti-vaxxers, their battle with traditional medical providers will probably continue for the foreseeable future. It is important that those of us who believe in the benefits of vaccines speak our minds. If the pro-vaccine majority are passive, the anti-vaccine minority will determine the national and international tone and policy.


Christopher Sanford, MD, MPH is associate professor in the Departments of Family Medicine and Global Health at the University of Washington, and a family medicine physician who specializes in tropical medicine and travelers’ health. His research interests include medical education in low-resource settings and health risks of urban centers in low-income nations.

To hear more from Christopher Sanford, come to his book talk at the University Bookstore on Tuesday, June 11th. To learn more about how to keep yourself healthy while traveling, buy his book.

What You Need to Know About the Measles Outbreak

In light of the current measles outbreak in the United States, we asked Dr. Christopher Sanford, author of Staying Healthy Abroad, to break down the statistics on measles nationally and globally for travelers across the country. He also answers some commonly asked questions about immunity and vaccinations.

The purpose of this article is educational. For medical advice for any health condition, please consult your physician.


Over 700 people in 22 US states have been infected with measles this year—the biggest measles outbreak in the US since 1994. Sixty-six of these people have required hospitalization. Most of those with measles had not been vaccinated for measles.

Per the WHO (World Health Organization), global measles deaths have decreased significantly in recent years, from 550,000 deaths in 2000 to 90,000 deaths in 2016 (an 84% reduction), but measles remains common in many low-income nations, particularly in Africa and Asia. An estimated 7 million people were infected with measles in 2016.

People immunized before 1989 may have only received one dose of measles vaccine. This provides partial protection, but better protection is provided by receiving a booster dose, that is, two doses of MMR (measles-mumps-rubella) total.

International travelers should receive a total of two doses of MMR vaccine. If travelers are uncertain as to their vaccine status, they may request serology (a blood test) from their medical provider to look for immunity. Those born before 1957 in the US are assumed to be immune to measles, mumps, and rubella from prior natural infection; vaccination with MMR is not advised.

Almost all US and Canadian universities and colleges began to require evidence of two prior doses of MMR vaccine (or proof of immunity) in about 1994.

Background

Measles is a serious viral infection that is transmitted by coughing and sneezing. The virus can live for up to two hours in an airspace or on a surface. Usual symptoms are fever, cough, rash, runny nose, and conjunctivitis (pinkeye). Although most people fully recover, complications include encephalitis—swelling of the brain which can result in permanent brain damage or death—and pneumonia.

The usual case-fatality rate in measles is 1-2/1,000 (0.1-0.2%). However, in malnourished populations, the case-fatality rate can approach one in ten.

In order to prevent sustained transmission of measles, 95% of the population needs to be immune, either from vaccination or natural infection (“herd immunity”).

In the US, in the decade 1912-1922, measles caused an average of 6,000 deaths per year. Prior to 1963, when measles vaccination became available, measles caused 4,800 hospitalizations, 1,000 cases of encephalitis, and 400-500 deaths each year in the US.

Washington State

In the current measles outbreak in Washington State, there have been 71 cases in Clark County (in southwest Washington, adjacent to Portland, OR) and one case in King County. The majority of these cases were in unimmunized people.

United States

There are currently measles outbreaks in 22 US states.

There were 372 cases of measles in the US in 2018. Between January 1 and April 26 of this year, 704 cases have occurred.

Most US cases are in children. Per a April 9 article in the Wall Street Journal:

New York City officials declared a public-health emergency as authorities elsewhere in the state announced new measures to halt the spread of measles, stepping up their responses after a recent surge in cases. The city on Tuesday ordered mandatory measles-mumps-rubella vaccination and fines for noncompliance in certain ZIP Codes in Brooklyn.

The current US vaccine schedule for measles: two doses; first at 12-15 months, second at 4-6 years. Boosters after initial series of two are not advised.

Global Picture

The dramatic decline in global measles is primarily due to increased vaccine coverage in low-income nations. However, should vaccine efforts wane, measles cases and deaths would inevitably markedly increase.

Many countries in Europe have seen a large uptick in measles cases in recent years. There are currently outbreaks in Germany, Ireland, Italy, France, and other European countries. Countries outside of Europe with current outbreaks include Israel, Ukraine, and Australia.


What’s the difference between elimination and eradication?

Eradication is the complete and permanent worldwide reduction to zero new cases of a disease through deliberate efforts. Smallpox has been eradicated from the planet. Elimination is the reduction to zero, or a very low defined target rate, new cases of a disease in a specified geographical areas. Measles was declared to be eliminated from the US in 2000.

How effective is measles vaccine?

Very. The two-dose series provides 97% protection.

What is herd immunity?

If a certain threshold level of a community is immune to a disease, either through infection or immunization, that infection cannot be propagated within that community. The threshold for different infections varies. For example, the level of resistance for polio in a community necessary to prevent an epidemic is 80%. Measles is more infectious; about 95% of a community needs to be resistant to measles to prevent epidemics.

What is the current measles vaccine rate in the US?

Fairly high. Currently, per the CDC, 94.3% of kindergartners were current for measles vaccine in the 2017-18 school year. However, this rate is markedly lower in some communities, e.g., the Orthodox Jewish community in Brooklyn, NY, and Clark County, WA, in which measles epidemics are currently occurring.

How can I tell if I’m immune to measles?

If you’ve received the two-dose series of MMR (measles, mumps, rubella) vaccine, it is reasonable to assume that you’re immune. If your vaccine history is uncertain, options include a blood test to check immunity, or receiving the two-dose series.


Christopher Sanford, MD, MPH is associate professor in the Departments of Family Medicine and Global Health at the University of Washington, and a family medicine physician who specializes in tropical medicine and travelers’ health. His research interests include medical education in low-resource settings and health risks of urban centers in low-income nations.

To hear more from Christopher Sanford, come to his book talk at the University Bookstore on Tuesday, June 11th. To learn more about how to keep yourself healthy while traveling, buy his book.