No, COVID-19 vaccines do not increase the transmission of the virus

New COVID-19 cases have been surging in Germany, and much of Europe, in recent weeks, prompting outgoing Chancellor Angela Merkel to announce new restrictions on the unvaccinated and the CDC and the U.S. State Department to issue travel advisories to Americans to avoid traveling to the country.

In a seven-day stretch ending Dec. 7, Germany reported an average of 55,379 new cases per day, according to data from Reuters. While the vast majority of the cases are among the unvaccinated, there has also been a significant increase in breakthrough infections among fully vaccinated people over age 60, according to the Robert Koch Institute, Germany’s state infectious-disease agency.

Some are using that data to falsely state that vaccines are increasing the spread of COVID-19.

"COVID-19 vaccines do not stop transmission of COVID, but instead increase it" declares a headline on a video shared on Facebook that claims new research shows vaccines have failed to halt transmission of the virus.

This video was flagged as part of Facebook’s efforts to combat false news and misinformation on its News Feed. (Read more about our partnership with Facebook.)

The video is hosted on a site called BitChute, which the Anti-Defamation League describes as a service that "has become a hotbed for violent, conspiratorial and hate-filled video propaganda." The two-minute video is a clip from a broadcast of RT, formerly known as Russia Today, an American cable television network funded by the Russian government.

In it, a reporter for the network quotes what she says is a medical study published in the medical journal The Lancet, saying that new research shows that among new cases involving people over age 60, the percentage that are breakthrough infections increased from 16.9% in July to 58.9% in October. She goes on to say that this shows that fully vaccinated people are a major source of COVID transmission.

Below the video, there is a link to a RT article on the topic, with the headline "Mass vaccination fails to halt Covid transmission rates – study."

However, the "medical study" referenced in the video and the story is not a study, but rather an opinion letter published in The Lancet, written by Günter Kampf, a professor at the University of Greifswald’s Institute for Hygiene and Environmental Medicine in Germany. That letter links to statistics from the Robert Koch Institute.

The Lancet says on its website that it publishes correspondence from readers and that they "are not normally externally peer reviewed."

The Robert Koch Institute said on its website that "the extent to which the vaccination reduces the transmission of the virus cannot currently be precisely quantified," but that "all in all, the risk that people will become PCR-positive despite vaccination and transmit the virus is significantly reduced." It goes on to recommend booster shots due to the vaccines’ waning efficacy over time. 

The Koch Institute explains on its website that "a high number of active cases and a relatively high vaccination rate can therefore lead to an increase in the number of vaccination breakthroughs."

The Koch Institute said in a flier and in a Twitter thread that it’s misleading to talk of the percentage of breakthrough infections in a group without noting the fact that the vast majority of that population is vaccinated. Most of the cases and hospitalizations come from the unvaccinated population, the Twitter thread said.

Featured Fact-check

Instagram posts

stated on November 7, 2024 in Instagram posts

“2,038 suicides have been reported (Nov. 6) following Donald Trump’s election win.”

The Institute’s flier says, "a high proportion of those vaccinated among COVID-19 patients in hospital does not mean that the vaccination is not working." 

Germany has fully vaccinated 69% of its citizens, while 72% have received at least one dose, according to figures from Our World in Data published by The New York Times. That vaccination rate is better than many countries. However, it’s not high enough to stop the latest surge in cases in Germany, Dr. Susanne Herold, of the University Hospital of Giessen, told the Times.

Only 18% of Germans have received a booster shot of the vaccine, which the Centers for Disease Control and Prevention recommends as protections from the vaccine lessen over time.

The rise in cases in Germany coincides with a surge of the more contagious delta variant of the virus, according to CNN. The delta variant is more than twice as contagious as previous variants, the CDC said.

The video and the RT story also mislead on the results of a different study in the U.K., cherry-picking one part and saying "throughout Britain, the number of household contacts exposed to unvaccinated cases (23%) was slightly lower than the number exposed to vaccinated individuals (25%)."

The study by the Imperial College of London said ​​that people with breakthrough cases "infected 25% of their household contacts," while 23% of contacts exposed to unvaccinated COVID patients became infected. The study goes on to say that head-to-head comparison is difficult because of the small sample size and the fact that the study compares different age groups.

The study’s authors concluded that "​​fully vaccinated people can contract and pass on COVID-19 in the home, but at lower rates than unvaccinated people." Overall, it said that about 25% of fully vaccinated household contacts tested positive for COVID-19, compared with 38% of unvaccinated people.

Professor Ajit Lalvani, co-author of the study, said that "vaccines are critical to controlling the pandemic" as they prevent serious illness and death, but the study shows that vaccination alone isn’t enough to prevent the spread of the delta variant in household settings.

According to the CDC, no vaccine is 100% effective and breakthrough infections were always expected. That doesn't mean the vaccine isn’t working. The good news for those fully vaccinated people who get infected is that symptoms are generally less severe and they are less likely to be hospitalized or die, the CDC says.

Unvaccinated people had a 5.8 times greater chance of contracting the virus and a 14 times greater chance of dying than unvaccinated people in September, the CDC said. 

PolitiFact, while debunking a similar claim in October, found that the biggest threat to unvaccinated people is other unvaccinated people.

A headline and video claim that "COVID-19 vaccines do not stop transmission of COVID, but instead increase it." As proof, it cites statistics from a recent surge in breakthrough cases among people over 60 in Germany.

While breakthrough infections have risen in Germany among people over 60, it’s misleading to say the vaccines do not stop transmission of the virus and wrong to say it increases it.

The claim fails to take into account that there are far more vaccinated people than unvaccinated in Germany, that the delta variant is more highly contagious than previous versions of the virus, and that the effectiveness of vaccines wanes over time, particularly among the elderly, who often received them earlier than others and have not yet gotten booster shots.

We rate this claim False.