Home > Pediatrics > Are Vaccines Safe? Get the Flash Player to see this player. Rate: (Click the stars to rate) Published on Oct 07, 2012 by ascales, Views: 3011 Vaccines are extremely safe. Adverse reactions are uncommon. The most common reaction is pain and swelling at the vaccine site, which is easily treated, and has no longterm problems. An allergic reaction to vaccines are rare. Vaccines are safe in infants. Vaccines do not cause autism. The studies looking at this were flawed. Vaccines do not cause brain damage because of mercury.