Secondary effects of Covid vaccines remain limited

In 70 cases, reactions occurred explicitly after the second vaccination dose Keystone / Peter Klaunzer

Health regulator Swissmedic has so far received 862 reports of suspected adverse reactions following a Covid-19 vaccination in Switzerland. This corresponds to around one case per 1,000 vaccine doses administered.

This content was published on March 26, 2021 - 10:09

“There is no evidence to date of any new safety signals,” Swissmedic said in a statementExternal link on Friday.

The majority of the reports involved more than one reaction (a total of 2,154 reactions, averaging 2.5 per report). The most common were injection site reactions (redness, itching, pain and swelling), fever, headaches, muscle pain and shivering. Cases with these reactions accounted for more than half of the reports (56%).

The average age of those affected was 64.4 (with a range of 16-101); 42.7% were over 75. In two-thirds of the cases women suffered from the side effects.

Three out of ten adverse reaction reports, or 263 cases, were classified as serious. The most common reactions in these cases were fever, shortness of breath, hypersensitivity, anaphylactic reactions, infection with Covid-19, vomiting, dizziness, headache and reactivation of shingles.

Regarding the “infection with Covid-19” cases, Swissmedic said those reports related to cases of Covid-19 where there was a correlation in time with the vaccination. “Since the vaccinated persons had not been tested before they were vaccinated and the human body first needs to build up its protection against the virus, the onset of Covid-19 disease in temporal correlation with vaccination is possible,” it said. “However, there is no causal link with the vaccination. Unlike live vaccines – e.g. those against measles, mumps and rubella (MMR) – Covid-19 vaccines do not contain (attenuated) viruses and cannot therefore trigger Covid-19 disease.”

Some of the “serious” patients, whose average age was 70.6, did require hospital treatment, Swissmedic said. In most cases, however, they were not in danger.

In 70 cases, reactions occurred explicitly after the second vaccination dose.

Some 460 reports were received after vaccination with the Pfizer/BioNTech vaccine and 393 after a Moderna vaccination. In nine cases, the vaccine was not specified.

No deaths due to vaccination

Thirty-seven people died “at differing intervals after receiving the vaccine”, Swissmedic said. These cases were “analysed with particular care”. Their average age was 84 years, and the majority of them had serious pre-existing conditions.

“As far as is known at present, death was caused by conditions such as infections, cardiovascular events or diseases of the lungs and airways that occurred independently of the vaccinations,” it said. “Despite a chronological correlation, there is no concrete evidence to suggest that the vaccination was the cause of death.”

For Swissmedic, the reported adverse reactions do not change the positive benefit-risk profile of the Covid-19 vaccines.

Swissmedic emphasised that the known side effects that are not serious do not have to be reported. These include temporary pain and swelling at the injection site, fatigue, chills, fever, headache and muscle and joint pain.

According to the Federal Office of Public Health, around 1.25 million vaccine doses have been administered in Switzerland up to and including March 21, 2021, and roughly 466,000 people have been fully vaccinated. 

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