Vaccines rarely cause serious side effects, health officials say. When problems do arise, they most often occur in people with preexisting immune system disorders.
The report, issued Thursday by an independent panel of medical experts convened by the Institute of Medicine -- which provides independent, science-based analyses -- should be used to help administer claims through the Vaccine Injury Compensation Program. That program was established in 1986 to provide financial compensation to people who were harmed by eight recommended vaccines.
Vaccine safety is a highly charged issue. Fears that vaccines can cause various side effects have led to a decline in childhood immunization rates in recent years and a re-emergence of preventable infectious diseases such as pertussis and measles.
"The utility of this report is enormous," said Dr. Ellen Wright Clayton, the committee chairwoman and director of the Center for Biomedical Ethics and Society at Vanderbilt University. "Claimants and the government and the vaccine court will now have available to them the best analysis that has ever been done about the potential adverse events caused by these vaccines."
The committee reviewed more than 1,000 scientific articles to assess vaccine safety. The report, the first comprehensive review of the issue by the Institute of Medicine since 1994, supports several previous analyses that failed to find a link between the measles-mumps-rubella vaccine and autism.
Moreover, the panel said they could find no evidence showing the diphtheria-tetanus-acellular pertussis vaccine causes type 1 diabetes or that the flu shot worsens asthma or causes Bell's palsy, a nerve disorder that causes temporary paralysis of the muscles in the face.
However, committee members said they found evidence that various vaccines can cause a range of side effects, usually minor, such as fainting or soreness at the injection site. For example the measles-mumps-rubella vaccine can cause fever-related seizures, although such seizures rarely cause any permanent disability.
Six vaccines, including MMR, influenza, varicella, hepatitis B, meningococcal and tetanus can cause an allergic reaction as well anaphylaxis, a sudden, life-threatening allergic reaction, according to the report. The varicella vaccine can cause rare cases of pneumonia, meningitis, shingles, chickenpox and other conditions in people with immune-system disorders as well as some people with healthy immune systems.
Doctors typically a case-by-case decision on which vaccines should be avoided in immune-compromised patients, said Dr. Douglas J. Barrett, a professor of pediatrics at the University of Florida and a committee member.
The report does not answer one of the most pressing questions regarding vaccine safety. Gardasil, a vaccine to protect against common strains of human papilloma virus that can cause cervical cancer, has been linked in isolated case reports to blood clots and even some deaths. But the report says there is not enough scientific evidence yet to determine whether HPV vaccines can cause side effects.