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Vaccine Safety and Loving Our Neighbors

In the wake of a recent outbreak of measles originating at Disneyland and spreading to more than 20 states, California state legislators have passed a bill implementing mandatory vaccination for students attending public schools. The grassroots uprising against this legislation surprises and disappoints me. This is a charged topic, but it seems that this reaction is primarily rooted in misinformation and a false sense of security that may also involve a failure to consider civic responsibilities. I share here my scientific perspective on vaccine safety and my Christian perspective—that vaccinations can be an apologetic demonstration of Christlike love for our neighbors.

Let me say now that I have no ties to pharmaceutical or vaccine companies. As a virologist, I have spent nearly 25 years teaching, studying, and researching viral pathogenesis (how viruses cause disease) and correlates of immunity (what aspects of the immune response are necessary for protection from viral infections). Much of my research involved vaccine proof-of-concept studies. Motivated by the love of God, and informed by years of study, I saw my research as a form of creation stewardship and as a way to love and serve others. I felt like my work was making a direct contribution to redeeming aspects of human disease and suffering.

I offer my perspectives from a passion for the well-being of others. Vaccination is a rich opportunity for our Christian witness based in the precept of loving others as ourselves, caring for the least of those among us, and considering others as more important than ourselves (Matthew 25:40; Philippians 2:3). On these grounds, my appeal echoes that offered by family physician Matthew Loftus in Christianity Today (May 2015).

Viruses Kill—Vaccines Save Lives

Successful US immunization campaigns have erased some diseases from day-to-day concerns—measles, polio, and rubella are no longer endemic, and incidences of mumps, chicken pox, hepatitis B, and whooping cough are greatly reduced. Decades of successful childhood immunizations have led many in society to no longer see their need for vaccines or their responsibility to act for the benefit of shared public health.

However, as recent measles outbreaks have demonstrated, we are not as protected and insulated as we think. Many viral-associated diseases are just a plane ride away. Measles is endemic in many other countries and is highly contagious. Globally, measles kills about 16 people every hour. Outbreaks occur in the US when individuals are infected abroad, return to the States, and come in contact with unvaccinated people. Continued widespread immunization is necessary to prevent such outbreaks and to protect those most vulnerable.

Evaluating Vaccine Safety

Vaccines administered in the US undergo rigorous evaluation. Long before licensure, research laboratories conduct proof-of-concept (preclinical) studies for potential vaccines. Relevant animal models are employed to demonstrate safety, immunogenicity, and efficacy. This multi-year process examines the extent and ability of potential vaccines to elicit an immune response and it examines the level of protection offered from subsequent challenges with the actual virus.

Once the best potential candidate is identified, production of the vaccine occurs under highly regulated manufacturing processes. Only then can prelicensure clinical trials begin, which are a multi-stage, highly regulated process that evaluates safety at every step in increasing populations. (See table.) If and when the vaccine successfully passes through clinical trials, panels of Food and Drug Administration (FDA) and non-FDA experts review all preclinical and clinical data prior to licensure. Even after licensure, safety evaluations continue through the nationwide Vaccine-Adverse Event Reporting System (VAERS) and, if warranted, in Phase 4 clinical trials. Many times the scientific community foresees potential side effects and may call for further scrutiny prior to licensure as is the case for current Dengue vaccine trials.1 (Dengue virus threatens millions worldwide each year.)

The FDA has a specific division dedicated to oversight of vaccine manufacturing and development and pre-licensure clinical trials. If at any time before, during, or after licensure a vaccine demonstrates dangerous adverse side effects, the FDA can demand more studies, halt manufacturing and administration, or revoke licensure.

FDA/CBER Road to Vaccine Approval

Initial human studies evaluated for safety and immunogenicity in a small number of closely monitored volunteers.
Preclinical Studies and Manufacturing Candidate vaccines undergo extensive evaluation
for animal safety and immunogenicity and for Good Manufacturing Protocols (purity, sterility, stability, potency, reproducible lots, assay validation, quality control, assurance, etc.).
Phase 1 Clinical Trials Initial human studies evaluated for safety and immunogenicity in a small number of closely monitored volunteers.
Phase 2 Clinical Trials Dose-ranging studies evaluate safety and immunogenicity at various doses in dozens to several hundred volunteers.
Phase 3 Clinical Trials Evaluates disease prevention and safety in large and
diverse populations (usually 1,000s–10,000s).
Application for Licensure Internal FDA review and external FDA review: Data from all preclinical and clinical studies and manufacturing protocols reviewed by experts, including scientists, doctors, regulators, and consumer advocates.
Continued Monitoring (Optional Phase 4) Even after licensure some vaccines may undergo Phase 4 clinical trials to collect more information under certain conditions or in certain populations. All vaccines undergo continued safety and manufacturing evaluations and reviews. Adverse events are reported via VAERS.

The FDA rigorously and continuously evaluates all components of licensed vaccines for purity, potency, and safety. Continued monitoring has helped suspend or halt production and use of poliovirus, rotavirus, and respiratory syncytial virus vaccines when adverse side effects were detected.

Refuting a Falsified Study

In 1998, British surgeon A. J. Wakefield published research on an extremely small number of individuals suffering from bowel disease and implied a link between vaccination and onset of autism. It was later discovered that Dr. Wakefield had falsified data and had a direct conflict of interest in discrediting the MMR vaccine. The journal Lancet retracted the article and Dr. Wakefield was banned from practicing medicine in the UK.2

More importantly, other researchers have never been able to corroborate his research findings. Numerous additional studies (from multiple countries and multiple research groups) have since documented vaccine safety in extremely large populations and have found no association of vaccination or thimerosal (a vaccine preservative) with autism or any other developmental disease. The data overwhelmingly supports the safety of vaccines. Even the national autism advocacy organization Autism Speaksindicates the safety and need for vaccination.

Real side effects (not autism) occur in a low percentage of those vaccinated. The side effects are very rare and, in many cases, pale in comparison to the risks associated with contracting the disease if unvaccinated. The risks for each vaccine should be discussed with your doctor or pediatrician.

Loving Our Neighbors

One of the amazing things about national vaccination campaigns is that you don’t have to reach every single individual. Based on epidemiological studies measles vaccine coverage of approximately 95 percent is sufficient to protect almost 100 percent of the population.3 As the Disneyland outbreak demonstrated, this “herd immunity” is critical in protecting those who are immunocompromised (due to age, illness, or treatments) and unable to receive or elicit a protective response to vaccination. I believe protecting the vulnerable is a critical part of our Christian witness.

For the sake of others, please consider immunizations. Consider vaccinations for your children’s well-being and safety. If you think your child is receiving too many immunizations at once, discuss it with your pediatrician. Please avoid spreading misinformation and unsubstantiated, falsified reports. Instead consider what impact you might have with your unbelieving neighbors if you shared with them the conviction that you vaccinate, despite uncertainties, for the sake of their children and the most vulnerable in society.

  1. Sri Rezeki Hadinegoro et al. “Efficacy and Long-Term Safety of a Dengue Vaccine in Regions of Endemic Disease,” New England Journal of Medicine 373 (September 2015): 1195–206, doi:10.1056/NEJMoa1506223; Luis Villar et al., “Efficacy of a Tetravalent Dengue Vaccine in Children in Latin America,” New England Journal of Medicine 372 (January 2015): 113–23, doi:10.1056/NEJMoa1411037; Cameron P. Simmons, “A Candidate Dengue Vaccine Walks a Tightrope,” New England Journal of Medicine 373 (September 2015): 1263–64, doi:10.1056/NEJMe1509442; Anna P. Durbin and Stephen S. Whitehead, “The Dengue Human Challenge Model: Has the Time Come to Accept This Challenge?,” Journal of Infectious Diseases207 (March 2013): 697–99, doi:10.1093/infdis/jis749.
  2. See T. S. Sathyanarayana Rao and Chittaranjan Andrade, “The MMR Vaccine and Autism: Sensation, Refutation, Retraction, and Fraud,” Indian Journal of Psychiatry 53 (April–June 2011): 95–96; and Jeanne Whalen, “U.K. Bans Doctor Who Linked Autism to Vaccine,” Wall Street Journal, May 24, 2010,
  3. “CDC: With Low Vaccine Rates, Some Areas Risk Losing Herd Immunity,” Advisory Board Company, published October 21, 2014,