Reinfection rates do not tell the whole story about protection against COVID-19

Israel led the world with its COVID-19 vaccination campaign, launching in December 2020 and quickly vaccinating the majority of those over age 60. Because of its early vaccine rollout, the country has been a bellwether for COVID-19 immunization outcomes.

So the world took notice when COVID-19 cases began to rise this summer among vaccinated Israelis, and vaccine critics took aim. 

"Thanks to (Israel's) sacrifice, we now know that natural immunity is far superior with 1% experiencing re-infection while 40% of new cases were previously vx'd," read one viral Facebook post. 

The post 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 figures in the statement appear to be based on media reports, but they lack important context. As of late July, vaccinated people represented a higher percentage of new COVID-19 cases in Israel than those who are unvaccinated. But among Israelis who were fully vaccinated and experienced breakthrough infections, the COVID-19 vaccine was 88% effective in preventing the need for hospitalization and 91% effective against severe illness. 

Comparing reinfection rates to gauge protection against the virus, as the claim does, ignores the dangers of contracting COVID-19, which is how natural immunity occurs. Israel’s data from January and July shows the differences in risk for an unvaccinated and vaccinated population. 

In January, when the country’s vaccine campaign was still in its early stages and infections were peaking, there were 1,100 patients in serious condition. On July 25 — with the country facing a new outbreak fueled by the delta variant, but with more than 60% of its population vaccinated — serious cases numbered 101. 

In January, Israel recorded 1,471 deaths from COVID-19, compared with 49 deaths in the month ended Aug. 2.

Now, about 1.6% of cases in Israel become critically ill, compared with 4% during an earlier wave of cases when vaccine coverage was low, according to a tweet by Eran Segal, a scientist at Israel’s Weizmann Institute of Science who tracks COVID-19 data. 

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The Facebook post was an image of a July 17 tweet by Del Bigtree, chief executive officer of Informed Consent Action Network, a U.S. anti-vaccination group, who has spread misinformation before. During the COVID-19 pandemic, Bigtree has made misleading claims about the risks to children of wearing masks and spread other false claims about the virus. 

A Facebook post claimed, "Thanks to (Israel's) sacrifice, we now know that natural immunity is far superior with 1% experiencing re-infection while 40% of new cases were previously vx'd."

The figures lack important context. Calling natural immunity "far superior" ignores the dangers of contracting COVID-19, which is how natural immunity occurs. And the claim ignores the effectiveness of the vaccines in preventing hospitalization and severe illness. 

Data shows that among Israelis who experienced breakthrough infections, COVID-19 vaccines were 88% effective against hospitalization and 91% effective against severe illness. And with a majority of its population vaccinated, Israel has seen huge reductions in serious cases and deaths. 

The statement contains an element of truth but ignores critical facts that would give a different impression. We rate this claim Mostly False.