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The Ethics of Smallpox Immunization

May 9, 2009 | by Daniel Eisenberg, M.D.

A Jewish perspective on the controversial issues surrounding immunization.

The eradication of smallpox may have been the greatest feat of medical science. Smallpox is estimated to have killed more people than any other disease in history, approximately 300 million people in the 20th century alone. It kills about one third of all infected people. This disease was the scourge of the world for millennia and then it was gone. Thanks to the World Health Organization, there has not been a single naturally occurring case of smallpox since 1977 and there has been no need to immunize against the disease in the United States since 1972.

With this in mind, it is possible to understand the horror that civilized people feel when considering the possibility that smallpox could be used as a biological weapon by terrorists or rogue nations.

Interestingly, Edward Jenner created the very first modern vaccine in 1796 to combat smallpox when he inoculated the first person with cowpox (a related, but much more benign disease), creating immunity to smallpox. Since that time, we have developed many vaccines against many deadly infectious diseases, particularly deadly childhood diseases.

Vaccination Risks

While vaccination has led to the virtual eradication of a host of deadly diseases such as polio, whooping cough, diphtheria, and measles, vaccination still remains controversial for some. This is primarily because vaccinations are not without side effects. People have long weighed the risks of preventive vaccination against the risk of deadly disease. Even before Jenner introduced the vaccinia smallpox vaccine (essentially the same vaccine we use today), people would deliberately infect themselves with smallpox via the skin with material taken from sufferers of smallpox, with the hope of developing a milder case of the disease. Faced with the virtual certainty of catching severe, natural smallpox, many people sought out this procedure, called 'inoculation,' which had an approximately .5-2% mortality rate. This was considered better than the expected mortality rate of about 30% from wild smallpox.

Despite the significant statistical advantage of immunization over disease, as a general rule, no one wants to be responsible for directly causing the injury or death of someone else. While the risk of death from a contagious disease may be high, it can be viewed as a random event. The parent who agrees to allow their child to be immunized is doing a definitive physical action that could bring harm to their child. There are even some Jews who oppose vaccination because of the Biblical command of "walk simply before the Lord, your God," which means "walk with Him in simplicity and anticipate His support, and do not delve into the future."

In Jewish law, this is the issue of "shev v'al taaseh" -- sit and do not act -- versus "maaseh" -- choose the proactive response. Generally, if the outcome of action versus inaction each has a significant downside, we opt for inaction. For this reason, some parents, both Jewish and non-Jewish, object to immunizing their children.

If the risk of disease far exceeds the risk of vaccination, action is usually preferable.

But this rationale only makes sense if the risks are equivalent. If the risk of disease far exceeds the risk of vaccination (which is usually the case), then the maaseh (action) is usually preferable.

For this reason, we assume that not immunizing our children for fear of complications is irrational. But that is only because we consider the risk of disease to be so much higher than the risk of immunization, that we consider the latter risk to be inconsequential.

It is important to emphasize that vaccination is permitted, even when there is a small risk of death from the vaccine. In fact, in the 19th century, Rabbi Yisroel Lipshutz, known as the Tiferes Yisroel, ruled that the smallpox vaccine is permitted, despite the risk of death. Interestingly, he also lists Edward Jenner as a "righteous gentile" for the development of the smallpox vaccine that saved hundreds of thousands of lives. It is important to note that the Tiferes Yisroel wrote at a time when smallpox was still a major killer, dwarfing any side effects of the vaccine by the tremendous number of deaths from the disease. Rabbi Lipshutz's ruling was true when many contagious diseases such as smallpox were common. But is it still true when immunization has virtually eliminated the incidence of these diseases? When risk of dying of the disease decreases to the point of being less than or equal to the risk of dying of the immunization, what is the proper course?

Jewish law would certainly insist that any possible methods of reducing the risks associated with vaccination be implemented. Additionally, once the risk of disease has sufficiently declined, the risk of vaccination is no longer justified. Nevertheless, we must take into account that the risk of disease reemergence might justify continued immunization.

For this exact reason, the United States has recently switched from the oral Sabin vaccine, which has a 2-4 in a million chance of causing polio, to the less powerful, but safer, Salk vaccine because the risk of polio from the oral vaccine approached the risk of acquiring wild polio. This will be discussed in greater depth later.

If everyone else is doing it, why should I?

Once the risk of infection from a communicable disease becomes very small, we are faced with another question. If everyone around me is immunized, should I accept the risk of immunization? As the Archives of Pediatrics and Adolescent Medicine (April 2001) explains:


"Herd immunity, the concept of decreased infection in susceptible individuals as a result of vaccination among household or community contacts, is generally thought to have a positive effect on the public health. Because of herd immunity, the incidence of several vaccine-preventable illnesses has dropped precipitously even though significantly fewer than 100% of the eligible population has been immunized."


I run a very small risk of becoming infected (because there simply is no one around me likely to catch the disease and pass it on to me) and my lack of immunization does not threaten anyone else, as long as they are immunized. Statistically, this argument makes sense. We only need a certain percentage of the population to be immunized to control a given disease.

However, practically, the logic is problematic. If everyone took this approach, no one would be immunized and the threat of deadly disease would skyrocket. We are beginning to see this phenomenon with respect to some childhood diseases.1 This is why society requires universal immunization, tolerating non-compliance only when public health is not threatened. On a small scale, we see what can happen when a population is not immunized by looking to the high polio rate in the Amish community.

One may suggest that the halachic concept of "God watches over the simple," in cases of risk that are generally accepted by the community (explained in my previous article "Taking a Risk" might allow me to forgo immunization. This would be a difficult argument to make since most people are not willing to accept the risk of forgoing vaccination.

Am I required to be vaccinated?

We must still ask whether Jewish law would require vaccination in the face of serious disease. There are several possible reasons why we might think that vaccination might be required. Some involve our obligations to ourselves, and some our obligation to others.

Maimonides derives the obligation to heal from the command to return a lost object. He reasons that if one must return someone's object, surely one must return someone's health. Several modern scholars rule that this mitzvah includes an obligation to prevent someone from losing their health in the first place.

Additionally, the Torah requires us to guard our health. As a result, we must seek medical care and avoid unnecessary risk (see "Taking a Risk"). But Maimonides makes it very clear that we are also required to actively guard our health, which means pursuing preventive measures (exercise, good diet, etc.).

It appears that immunization is a part of a Torah mandated preventive health program.

The Code of Jewish Law (Shulchan Aruch, Yoreh Deah, 116) describes an obligation of actively preventing illness and danger. There is clear evidence of a mitzvah of preventive health precautions in the halachic rulings regarding people living in towns that are being struck by a plague. One is required to take precautions to avoid contracting the illness. There is even discussion that states that if one was present in a town when a plague struck and he survived, he is not required to leave that town if the plague strikes again, presumably because he is now immune. It would appear that immunization is a part of a Torah mandated preventive health program.

The Torah also requires that you "Do not stand idly by as your neighbor's blood is being shed." This mitzvah is interpreted by the Talmud to require one to expend positive effort and even money to protect an endangered person. Sefer HaChinuch, a medieval explanation of the 613 mitzvot of the Torah, rules that communal responsibility is learned from this verse. We may logically extend his ruling to an obligation on each individual to prevent others from becoming sick, by such means such as vaccination, (particularly in times of epidemic) in order to decrease the risk of our spreading disease to others.

Rabbi Shlomo Zalman Aurbach was the preeminent decisor of Jewish law in Israel of the latter 20th century. In discussing what constitutes danger to life, he ruled that if one was sufficiently scared of not being vaccinated, and the only opportunity to be immunized would be on the Sabbath (or one would have to wait a few years), then immunization would be permitted on the Sabbath! In such a case, immunization must clearly be considered to be a mitzvah.

There are several other Biblical and Rabbinic sources that may require preventative action to guard against disease, however the above short survey certainly establishes the point that vaccination may be considered a part of the obligation to guard our individual and communal health.

Can we compel vaccination?

We are still left with a very crucial question: Can society mandate vaccination, despite the risk involved to those being immunized?

Society has many reasons to encourage universal vaccination, primarily the protection of the population from illness and preventing the huge economic cost of contagious diseases (both healthcare costs and lost productivity). But from a Jewish perspective, may we compel vaccination?

Rabbi Sholom Kamenetsky, of the Talmudical Yeshiva of Philadelphia, argues that while it is proper for society to mandate wide scale immunization without worrying about the rare serious complications, individuals may refuse the immunization as long as their refusal does not pose a public health risk. Were a sufficiently large number of people to refuse vaccination to the point of causing a public health risk, then society may compel everyone to be vaccinated. It would not be proper at that point for us to choose which people may be exempted from the small risk of vaccination while others are compelled to comply. Of course, this does not apply to people with medical contraindications to vaccination.

With a slightly different approach, Rabbi Yehoshua Neuwirth, a major contemporary Israeli posek rules :2

"One may not obligate any healthy person to receive treatment as a preventive measure. Although one may try to convince the individual, he may do no more. If there was absolute evidence that [an individual] could be a danger to others, such as in spreading infection which could be fatal, then there would be a case for forcing him to have a vaccine, but only if it was certain that the vaccine itself was not dangerous to him."


Another contemporary Jewish legal expert, Rabbi Eliezer Yehuda Waldenberg, rules that even preventative medical treatments may be compelled (such as eye exams for yeshiva students).

Unintended consequences: chicken pox

In addition to the ethical consideration raised thus far, there are scientific considerations that have ethical consequences. The chicken pox (varicella) vaccine raises another issue regarding vaccination. Chicken pox is a usually benign childhood illness. While the infection is very inconvenient, it is rarely fatal in children. However, while adults are less susceptible to varicella infection, they are more likely to die of chicken pox. In fact, varicella can be a very serious adult infection. We have a dilemma both for individuals and for society. A child who develops chicken pox is essentially protected from reinfection (although shingles is a common adult sequella). If we immunize most children, but not all, then the incidence of the disease will drop and those people not immunized will be less likely to develop the disease as a child and more likely to develop it as adults when it is dangerous. In essence, for a small portion of the population we would be shifting the risk of chicken pox from childhood to adulthood and increasing the mortality from chicken pox!

Therefore, if the vaccine afforded protection for life, there would be a very strong argument in favor of universal vaccination -- no chicken pox and no shingles. Both children and adults would benefit -- children would not develop chicken pox as children or shingles as adults and no adults would be vulnerable to chicken pox as adults.

But what would happen if the vaccine only protected a person for 25 years? Should we worry that we will push off chicken pox in the entire population from childhood when it is benign to adulthood when it can be deadly? While boosters can be given, realistically, many people will never receive the booster and these people would have been better off developing the disease as a child.

The vaccine has been in use for 25 years in Japan with continued resistance. We can only hope that lifelong resistance can be demonstrated.

What type of vaccine should we use?

Even the type of vaccine that we use can be controversial. Vaccines come in two main types: live and killed virus. For example, the original Salk injected vaccine for polio, developed in the 1950's, is a killed virus, with no known risk of causing polio. The Sabin oral vaccine, developed a few years later, is a live attenuated (weakened) virus, that has a one in two to four million chance of causing polio. Why not just use the Salk vaccine?

Because the Salk vaccine causes only immunity in the blood, protecting the person vaccinated, but allowing them to spread the disease to others.

The Sabin vaccine causes an intestinal infection with the weakened virus, induces immunity in the individual who is immunized, and does not allow the spread of the polio virus to others. But more importantly, since the immunized person is infected with the weakened virus, they can spread it to the people around them, just as wild polio may be spread. This allows immunization even of people who do not receive the oral vaccine. The down side arises from this very advantage -- since the Sabin vaccine is a live virus it has a small risk of causing polio in those who are immunized directly or indirectly.

So we are faced with another dilemma. While the Salk vaccine can protect the individual who has been immunized, it cannot stop epidemics. On the other hand, the Sabin vaccine can prevent epidemics by vaccinating even those not receiving the immunization, but it has a very small, but serious, danger.

Do we put the emphasis on the individual (Salk vaccine) or on the population (Sabin vaccine)?

When polio was a major health threat, the United States utilized the Sabin vaccine. As mentioned above, now that the risk of polio has declined to near the risk of the oral vaccine, the United States has chosen to revert to the (safer) Salk vaccine.

Liability and immunization

Am I responsible for causing harm if I administer the Sabin vaccine to someone who develops polio from it or the smallpox vaccine and someone develops life-threatening vaccinia? Is the drug company that produces this (or any other) vaccine responsible for the rare, but predictable, complications that arise from their products?

Jewish law forbids one to harm himself. This prohibition is called "chovel b'atzmo." Additionally, if I ask someone to hit me, the one who hits me is liable to pay me damages for any harm inflicted.

Yet, while the Talmud clearly forbids one to harm himself, there are exceptions to this rule. If the benefit to be gained by self-inflicted injury outweighs the harm done, then it is permitted. The most obvious example is surgery. I certainly may give permission to the surgeon to operate on me for a life-threatening condition. As long as the surgeon acts competently, he/she is free from any liability for adverse outcome.

The same rule applies to liability for immunization. If the risks are clearly spelled out in advance to the best of our scientific knowledge, and there is no reasonable way to reduce the risk without compromising the vaccine, then the drug manufacturer and the person giving the injection are free of liability under Jewish law. Clearly, if there is a way to mitigate danger, but the manufacturer chooses not to do so, then there may be grounds for liability.

Should people take the smallpox vaccination?

The decision to accept immunization is essentially a risk-benefit analysis. We determine the prevalence and severity of disease and weigh it against the risk of vaccination. The ideal vaccine has virtually no side effects and protects against a common lethal disease. While this is rarely possible, very low incidence of severe side effects was achieved in the vaccinations for many (formerly) common deadly diseases such as pertussis, diptheria, and tetanus.

We are willing to tolerate a larger degree of danger from vaccination if the danger of disease is sufficiently high, such as the Sabin polio vaccine in the late 1950's. This certainly applied to the smallpox vaccine when the risk of infection was very high. Until the advent of HIV in the 1980's, a whole generation of Americans did not face the prospect of death from an infectious disease. The AIDS epidemic reawakened the drive for a new, effective, and safe vaccine for an infectious epidemic.

With no credible expectation of a smallpox outbreak, widespread vaccination is probably unjustified.

The difficulty in deciding on whether to take the smallpox vaccine is the unknown risk of disease. No one has developed the disease in over 25 years. Immunization side effects that were readily accepted when the disease was prevalent are now carefully scrutinized as people ask whether the risk of terrorist attack outweighs the risk of vaccination. Without more information from those who can best assess the risk, presumably the US (or Israeli) government, we are unable to make the necessary risk-benefit analysis.

Currently, the US government is not recommending widespread immunization, considering the risk to be sufficiently small to warrant leaving the population unvaccinated. With no credible expectation of a smallpox outbreak, widespread vaccination is probably unjustified, particularly since the vaccine may be effective soon after exposure. Nevertheless, the government is recommending that front line healthcare workers be vaccinated, likely as a purely precautionary step. We must assume that the government has information that would suggest that the potential risk of exposure to these healthcare workers justifies its recommendation that this selective group of people subject themselves to the very small risk of death from the vaccine.

The Israeli government, arguably at greatest risk of a smallpox attack, has reportedly immunized 40,000 soldiers and healthcare workers, but chosen not immunize the general population, with the expectation that the entire population could be immunized within four days if necessary. There is almost certainly a much smaller threat to the United States population than to the Israeli population.

As of now, we must "sit tight" and pray for a world in which the smallpox vaccine will never be needed again!




1. Incidence of pertussis in adults increasing 01-09-2003 (Reuters Health)
NEW YORK (Reuters Health) - Federal health officials are urging physicians to consider a diagnosis of pertussis in adults with a cough lasting 2 weeks or longer, especially those with fits of coughing, inspiratory "whoop," or post-tussive vomiting.

"The number of pertussis cases in adults has risen substantially since the 1980's," epidemiologists from the US Centers for Disease Control and Prevention report in the Morbidity and Mortality Weekly Report for January 9th. Adolescents and adults may be reservoirs for Bordetella pertussis in the community due to waning vaccine-induced immunity, they warn. As a result, the CDC says pertussis vaccination "might have a future role in the prevention of disease and control of outbreaks in older age groups."

CDC officials describe an outbreak of pertussis that occurred between August and October 2002 among workers at an oil refinery in Illinois. Seventeen workers were diagnosed with pertussis and another 7 patients with pertussis were identified in the community. All 24 were effectively treated with macrolide antibiotics.

Of note, pertussis was not initially considered in the index patient, who had a 14-day old cough, until the patient's supervisor also presented with similar symptoms.

According to the CDC, pertussis is the only disease for which universal childhood vaccination is recommended in the US that has increased in incidence during the past 20 years. MMWR 2003;52:1-4.
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2. Several of these ruling are found in DiPoce and Buchbinder, "Preventative Medicine," Journal of Halacha and Contemporary Society, Fall 2001 (no. XLII, p. 70-101).
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