Some vaccines can cause encephalitis and other complications, but these unpleasant side effects are rare. There is also no link between immunization and autism or other serious health problems, says the National Academy of Sciences, the US national academy of sciences.
The first such extensive analysis of the scientific evidence on vaccine safety in 17 years was carried out by a commission established by the Institute of Medicine, which is subordinate to the academy. Over a thousand studies have been analyzed in addressing the controversial issue of vaccine safety. In a 667-page report published on Thursday, a 16-person committee presented convincing evidence that vaccination can cause 14 different health problems, including seizures, encephalitis and syncope, but noted that such complications are extremely rare. The committee concluded that some vaccines can cause other complications, such as allergic reactions and joint pain. However, no relationship has been found between immunization and the most serious and questionable conditions: autism and type XNUMX diabetes.
– With the beginning of the school year, it is a good idea to make sure that your children have all their vaccinations. The safety report for these eight vaccines comes at a particularly opportune time, wrote Ellen Wright Clayton, professor of paediatrics and law at Vanderbilt University who chaired the committee, in a statement. – Conclusions should reassure parents. Several health conditions are related to vaccinations, but these side effects are extremely rare.
Since the entry into force of the Children’s Vaccination Act of 1986, the Institute of Medicine, commissioned by the US Congress, has conducted a study on vaccine safety 11 times. The last report was released in 1994. Based on these reports, the US Department of Health and Human Services administers the Family Compensation Program for Child Vaccine Injury Compensation. Vaccination safety has become the subject of intense debate in recent years. Some parents are concerned that the increasing number of compulsory vaccinations may create too many complications. This argument is most often invoked by those who refuse to vaccinate their children. Meanwhile, to growing concern from authorities, it has already been observed that massive vaccine avoidance has led to a recurrence of potentially life-threatening diseases such as measles. There has been a major measles outbreak in Europe this year and the number of cases in the United States continues to rise.
The Commission concludes that there is convincing evidence that the ternary measles-mumps-rubella (MMR) vaccine can lead to fever-induced attacks in some children, but reassures that symptoms are almost always short-lived and have never led to serious problems. complications. The MMR vaccine can cause a rare form of encephalitis in people with serious problems with the immune system, the committee warns. The varicella vaccine can cause brain swelling, pneumonia, hepatitis, meningitis, shingles and smallpox in a small number of patients, the committee said. However, most of these conditions affect people with diseases of the immune system.
The publication of the report was welcomed by supporters of childhood immunization. Critics emphasize, however, that the committee has clearly acknowledged that there is still not enough evidence to dispel some of the doubts surrounding vaccination once and for all.
– There is not enough scientific evidence to conclusively conclude that certain vaccines cause – or not – cause serious conditions such as encephalitis, encephalopathy, stroke, asthma, autism, sudden infant death, multiple sclerosis, arthritis, lupus, and blood disorders. problematic in a situation where the law makes vaccination of children mandatory and recommends it to adults, wrote Barbara Loe Fisher from the National Vaccine Information Center in an e-mail.
“Acknowledging that science still does not fully understand how vaccines affect the human body – including how, when, why, and to whom they may be at risk – the committee confirms that more research is needed into vaccine safety,” adds Fisher.
Text: Rob Stein
Facts and myths about immunization >>