Why are vaccine safety numbers still vague?

“I would often say that the risk of getting a blood clot with birth control pills is similar to a very serious reaction to penicillin,” said Dr. Raegan McDonald-Mosley, an obstetrician-gynecologist, said. and the CEO of Power to Decide, a group willing to reduce unintended pregnancies. She regularly discusses blood clot risk with her patients and tells them the increase in risk and the overall extent of the risk. According to her, most patients choose their form of birth control based on other considerations.

Penicillin, a widely used antibiotic, causes severe allergic reactions between one in five patients for every 10,000 people who take it.

For vaccines, however, the threshold for safety is generally higher than for other types of medicine. As many researchers have noted, Covid-19 also puts people at risk for serious blood clots – far more than any possible estimate of the vaccine effect. But not everyone who is not vaccinated will get sick.

“The disease you happen to get and the vaccine you get by choice, and that makes it harder,” said Dr. Steven Black, an emeritus professor of pediatrics at Cincinnati Children’s Hospital, said.

For other vaccines, the risk of serious side effects is much lower than for contraceptive pills or penicillin – it usually occurs in less than 1 in every 100,000 who receive a given vaccine. The rate is “clearly much, much less than a drug would have tolerated,” said Dr. Nicola Klein, director of the Kaiser Permanent Vaccination Study Center, which is involved in the Vaccine Safety Datalink study.

Most other vaccines protect against rare diseases. In contrast, Covid-19 remains widespread in the United States and in many parts of the world. Given the severity of the disease and its spread, vaccination may now be higher than when such considerations are usually considered.

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