By Purvi Parikh, MD

Mercy, a 21-year-old mother in Zambia, walked three hours to a health clinic with her 3-year-old son, Kelvin. Their goal: to vaccinate Kelvin against preventable diseases such as measles, rubella, pneumonia and polio “so he can grow up and be strong enough to attend school,” Mercy said.

Selina Chile, a 66-year-old volunteer in the clinic, also walks 5 kilometers daily to help clean floors, windows, and wash blankets for patients. She helps weigh babies and educates mothers. She has seen her four children and eight grandchildren vaccinated in the clinic and volunteers because she believes in the importance of life-saving vaccines, as she has witnessed deaths in those who were not vaccinated.

Mercy and Selina are not alone. The 20 clinics in the Livingstone district of Zambia treat 28,000 children under 5 and another 48,000 ages 5-15. Immunizations are given one day a week, so vaccines don’t have to be stored more than necessary in the heat and unreliable refrigerators. Often the vaccine fridges use solar panels so they are not without electricity when power goes out.

Despite the difficulties, the district has a 98 percent vaccination rate for measles, with comparable figures for other preventable diseases such as polio and pneumonia.

I was part of a team visiting the health clinic in 2016 with the United Nations Foundation’s shot@life, an advocacy group that raises awareness and money for international vaccine programs. I learned that every 20 seconds a child dies of a vaccine-preventable disease in the world.

These important vaccine programs provided 23.5 million children with measles vaccines in 2015 alone, not to mention vaccines against countless other infectious diseases.

The difference in attitudes I observed between parents in Zambia and parents in my area of New York City was astounding. I spend much of my time trying to convince American parents that vaccines are safe and necessary, while those I met in Zambia consider them a gift. They have seen diseases like measles wipe out children in entire villages. To them, vaccines offer their children a chance to study and achieve their goals in life.

Before the discovery of vaccines, contagious diseases like polio, measles and smallpox ran rampant through communities, killing huge numbers of people. Now, thanks to vaccines, smallpox has been eradicated and polio is almost non-existent.

In areas of the United States and elsewhere in the developed world where parents opt out of vaccines, measles, whooping cough and other dangerous diseases are making a comeback. If we stop immunizing, it wouldn’t take long for outbreaks to spread. Children who are not immunized put themselves and others at risk for these contagious diseases.


I receive many vaccination-related questions from parents. Here are some of the most common:

Why do I need to vaccinate my infant? Why can’t I wait until the child is older?

Babies are born with very immature immune systems. Newborns receive some immunity from their mother, but this quickly wears off and it takes time to build it up again. In the meantime, young children are vulnerable to disease, and vaccination is the best way to protect them. Delaying it just puts your baby and others at greater risk.

Are there side effects to vaccines? 

Vaccines require rigorous safety studies before FDA approval. Most vaccines available today have been used for decades, with few problems. Side effects are mild and rare. Over the years, vaccines have been made more safe and effective.

Do vaccines cause autism?

Vaccines do not cause autism. Vigorous studies around the world have found no connection. The original research that sparked this fear was a small study of only 12 children with what turned out to be falsified evidence.

Why do vaccines contain aluminum and mercury? Aren’t they dangerous?

Aluminum is an additive that makes the active ingredients more effective, while mercury (also called thimerosal) is a preservative. Both are naturally occurring elements widely found in our environment, and the amounts contained in vaccines are less than what a baby receives from breast milk.


Purvi Parikh, MD, is an allergist and immunologist with Allergy & Asthma Network. She practices in New York City at Allergy and Asthma Associates of Murray Hill and New York University School of Medicine. 


Reviewed by Tera Crisalida, PA-C and Dennis Williams, PharmD