
Almost all cases following vaccination occurred in the eight weeks after receipt of the vaccine. In contrast, influenza infection, which is also a cause of GBS, causes this condition in about 17 people per 1 million infections - 17 times more frequently than following vaccination.

Subsequent studies have found flu vaccines to be a cause of GBS in about 1 person per 1 million doses of vaccine. A 1976 swine influenza vaccine was identified as a rare cause of Guillain-Barré syndrome (GBS), an ascending paralysis that can involve the muscles of breathing.Influenza vaccine - Two severe adverse events associated with influenza vaccine are also instructive:.In this situation, vaccine virus replicates and spreads throughout the body onset occurs less than one week after vaccination, most often, occurring about three days after receipt of the vaccine. This adverse event happened so infrequently that it was not described until the early 2000s. Yellow fever infection can also cause multisystem organ failure. Viscerotropic disease - This condition is characterized by multisystem organ failure.When this happens, the average time between receipt of the vaccine and symptom onset is two weeks, with the range up to three weeks. It can also happen, albeit less frequently, in those older than 6 months of age who receive the vaccine.

It occurred most often when infants younger than 6 months of age received this vaccine, which is why this group is not recommended to get the vaccine.

This happened when genetic changes to weaken the virus in the lab were lost during viral replication in the vaccine recipient. Oral polio vaccine - About 1 in 2.4 million recipients of the oral polio vaccine, which is no longer used in the U.S., were paralyzed following vaccination when the vaccine virus reverted to “wild type” poliovirus.But when they do, these effects tend to happen within two months of vaccination:

The history of vaccines shows that severe effects following vaccination can occur. To answer this question, scientists study the available evidence, and while the rules of science do not allow scientists to say that long-term effects can never happen, the evidence is strong that these vaccines will not cause long-term harm.
SIDE EFFECTS OF COVID VACCINE IF YOU HAVE HAD COVID TRIAL
Short-term side effects (i.e., those that happen in the days after a vaccine has been given) are readily apparent because of clinical trial reports and personal experiences, but people also wonder about possible long-term effects of these vaccines. Since COVID-19 vaccines are new, some people have asked about their effects on those who take them.
