Here are some of the most com­mon­ly asked ques­tions about vac­cines.

Do vaccines cause autism?

No. Unvac­ci­nat­ed chil­dren are just as like­ly as vac­ci­nat­ed chil­dren to get autism. Nei­ther vac­cines nor any ingre­di­ent in vac­cines does any­thing to increase the risk of autism. How­ev­er, the vac­cine-pre­ventable dis­eases can cause severe ill­ness lead­ing to hos­pi­tal­iza­tion. They can also cause blind­ness, deaf­ness, men­tal retar­da­tion, and death.

MMR does not cause autism; but measles, mumps, and rubella can cause blindness.
The MMR vac­cine does not cause autism; but measles, mumps, and rubel­la can cause blind­ness.


The false rumors about vac­cine and autism were spread by dis­hon­est peo­ple who were try­ing to sell use­less prod­ucts and ser­vices to the par­ents of autis­tic chil­dren.

Why does my baby need shots against diseases I have never heard about?

Thanks to vac­ci­na­tion, dis­eases that used to be com­mon are now rare. For exam­ple, diph­the­ria used to be a major cause of death among chil­dren. Yet today, we may go for years with­out even one report­ed case any­where in the Unit­ed States. Unfor­tu­nate­ly, if we stop vac­ci­nat­ing against these dis­eases, they can come back. For exam­ple, vac­ci­na­tion rates fell in the Russ­ian Fed­er­a­tion after the col­lapse of the Sovi­et Union. As a result, there was a ter­ri­ble out­break of diph­the­ria in the ear­ly 1990s. Diph­the­ria remains a dead­ly dis­ease, even with the best of med­ical care: http://wwwnc.cdc.gov/eid/article/18/2/pdfs/11–0987.pdf

Why do vaccines contain mercury?

Many vac­cines, such as the MMR vac­cine, have nev­er con­tained the mer­cury-con­tain­ing preser­v­a­tive thimeros­al. Thimeros­al was used to pre­vent bac­te­ria and fun­gi from grow­ing in mul­ti­dose vials of vac­cine prod­ucts. It is also com­mon­ly used as a preser­v­a­tive in con­tact lens solu­tion. Thimeros­al had been used as a vac­cine preser­v­a­tive since the 1930s. There was nev­er any evi­dence that the thimeros­al in vac­cines was caus­ing any safe­ty prob­lems. How­ev­er, sci­en­tists at the CDC rec­om­mend­ed in 1999 that phar­ma­ceu­ti­cal com­pa­nies should make vac­cines with­out thimeros­al. Since 2001, prac­ti­cal­ly all child­hood vac­cines have been mer­cury-free. Only after this deci­sion was made, anti­vac­cine activists start­ed try­ing to use the threat of mer­cury poi­son­ing as a way to scare peo­ple away from vac­ci­nat­ing their chil­dren. As a result, many peo­ple are expos­ing their chil­dren to the risk of seri­ous ill­ness, per­ma­nent dis­abil­i­ty, or even death because of their fear of a preser­v­a­tive that was nev­er shown to be harm­ful and has been removed from prac­ti­cal­ly all vac­cines.

Why do vaccines contain formaldehyde?

Some vac­cines are made out of the dan­ger­ous tox­ins that are pro­duced by bac­te­ria. Dur­ing the man­u­fac­tur­ing process, these tox­ins are treat­ed with formalde­hyde to deac­ti­vate them. As a result, the tox­ins lose their abil­i­ty to harm the body. How­ev­er, the retain enough of their shape that the immune sys­tem learns to rec­og­nize them. The man­u­fac­tur­ers then remove as much of the formalde­hyde as pos­si­ble. Trace amounts of formalde­hyde do remain in some vac­cine prod­ucts, but these amounts are too small to do any harm. Formalde­hyde is a nat­u­ral­ly occur­ring organ­ic com­pound. The body pro­duces small amounts of formalde­hyde dur­ing nor­mal metab­o­lism of pro­teins. You would get rough­ly 50 times as much formalde­hyde from eat­ing a pear than you would get from a vac­cine.

Pears contain more formaldehyde than vaccines do.
A sin­gle pear con­tains far more formalde­hyde than you would get from a vac­cine.

Why are vaccines against hepatitis B and HPV being given to children?

Many par­ents are angry that the doc­tor wants to vac­ci­nate their child against some dis­eases that can be sex­u­al­ly trans­mit­ted: hepati­tis B virus (HBV) and human papil­lo­mavirus (HPV). How­ev­er, there are good rea­sons for giv­ing these vac­cines to chil­dren. First of all, not all cas­es of hepati­tis B are sex­u­al­ly trans­mit­ted. Hepati­tis B can also be spread by oth­er kinds of close con­tact, such as shar­ing a tooth­brush. Hepati­tis B can cause a chron­ic infec­tion that even­tu­al­ly leads to liv­er can­cer. Young chil­dren are the peo­ple who are most like­ly to devel­op this chron­ic infec­tion after expo­sure to hepati­tis B. By vac­ci­nat­ing young chil­dren, we pro­tect the chil­dren against liv­er can­cer. We also reduce the risk that they will be spread­ing hepati­tis B to oth­er peo­ple.

Hepatitis B virus causes liver cancer in children
Hepati­tis B virus caus­es a chron­ic infec­tion that can lead to liv­er can­cer. Babies are most at risk.


The stud­ies of the HPV vac­cine have shown that the vac­cine is most effec­tive in patients who have nev­er been exposed to any of the vac­cine strains of HPV. The HPV vac­cines are remark­ably safe, and they have already led to sharp decreas­es in the preva­lence of the vac­cine strains of HPV. Soon, these will trans­late into decreas­es in the inci­dence of cer­vi­cal can­cer in women and can­cers of the anus, mouth, and throat in women and men.

Famous people have died of HPV-related cancers
HPV can cause dead­ly can­cers.