Answering Your Doubts
Answering Your Doubts
Everything You Need to Know
1. Why are there so many recommended vaccines now compared with the past?
As medical science advances, vaccines have been developed for more pathogens that cause serious illness. Expanding recommendations aim to protect children from a broader range of dangerous diseases. The number of vaccines grows because we now have safe, effective vaccines that prevent diseases once common and often deadly.
Source: https://www.cdph.ca.gov/Programs/CID/DCDC/Pages/Immunization/family-answers.aspx
2. Do vaccines protect against diseases that aren’t common anymore?
Yes. Diseases like polio and diphtheria may seem rare in some countries because vaccines have controlled them. However, these diseases still exist globally and can return if vaccination rates fall, making continued immunization necessary.
3. If a disease is rare, why is the vaccine still recommended?
Even rare diseases can re-emerge — especially with international travel and declining immunization rates. The best way to keep these diseases rare is through continued high vaccination coverage.
4. Can vaccines cause allergic reactions?
Allergic reactions to vaccines can happen but are extremely rare (about 0.65-1.45 reactions per million doses). Most people won’t have any serious reactions; mild side effects (like redness, swelling, or low-grade fever) are far more typical.
5. Do vaccines cause seizures (including febrile seizures)?
Rarely. Febrile seizures occur in some children with fever from many causes, including infections. They are more often caused by infections than vaccines.
6. How do we know vaccine ingredients are safe
Every ingredient in a vaccine — including preservatives, adjuvants, and stabilizers — is tested extensively for safety and required to be in amounts far below harmful levels. Regulatory agencies like the FDA and Health Canada evaluate ingredient safety before approval and continue post-market monitoring.
Source: https://www.cdc.gov/vaccines-children/hcp/conversation-tips/questions-parents-may-ask.html
7. Isn’t it risky to give vaccines when a child has a mild illness?
If a child has a minor illness without fever (like a cold), vaccinations can usually proceed safely. Severe illness or fever may warrant rescheduling until recovery. Healthcare providers assess on a case-by-case basis.
Source: https://www.cdc.gov/vaccines-children/hcp/conversation-tips/questions-parents-may-ask.html
8. Why aren’t vaccines 100% effective?
While many vaccines induce immunity in 90–99% of recipients, individual immune responses vary. High population coverage (herd immunity) protects those who respond less well.
9. Why do children need a specific vaccine schedule?
The vaccine schedule is based on when children are most vulnerable to diseases and when vaccines are most effective at inducing immunity. Delaying vaccines leaves children unprotected when they are at highest risk.
Source: https://www.cdc.gov/vaccines-children/hcp/conversation-tips/questions-parents-may-ask.html
10. Do vaccinated children have stronger immune systems?
11. How serious are the diseases vaccines prevent?
Diseases like measles, polio, pertussis (whooping cough), and Hib meningitis can cause serious complications — such as brain damage, paralysis, deafness, pneumonia, and even death. Vaccines dramatically reduce these risks.
12. If someone in the community is vaccinated, why should my child get vaccinated?
High vaccination rates protect not only the individual child but also the community (herd immunity). This is especially important for those who cannot get vaccinated (e.g., infants, immunocompromised children). Herd immunity reduces the spread of disease and protects vulnerable populations.
Source: https://www.cdc.gov/vaccines-children/hcp/conversation-tips/questions-parents-may-ask.html
13. How do vaccines work?
Vaccines expose the immune system to a safe form of a pathogen (or part of it), triggering antibody and memory cell development so the body is ready if exposed to the real disease later. Vaccine immunity mimics natural infection without causing the disease.
14. Do vaccines cause long-term side effects?
Extensive research shows vaccines are not associated with chronic health problems such as autism or autoimmune diseases.
Source: https://www.cdc.gov/vaccines-children/hcp/conversation-tips/questions-parents-may-ask.html
15. Do vaccines contain harmful ingredients?
All vaccine ingredients have specific roles — to stimulate immunity (antigens), enhance response (adjuvants), or maintain safety (preservatives). Amounts are tiny and well below harmful thresholds.
Source: https://www.cdc.gov/vaccines-children/hcp/conversation-tips/questions-parents-may-ask.html
16. Do vaccines contain aluminum?
Some vaccines include small amounts of aluminum salts as adjuvants to strengthen the immune response. Aluminum exposure from vaccines is less than that from normal dietary sources and has a long safety record.
17. Is there mercury (thimerosal) in vaccines?
Thimerosal, a mercury-containing preservative, was removed from most childhood vaccines in Canada and the U.S. decades ago and studies show it was safe even before its removal.