mRNA vaccine protection from Covid is far weaker than natural immunity and declines very fast, according to a new study of almost 6 million people in Israel.
During the summer Covid wave, more than 140,000 Israelis who had been vaccinated but not received a booster shot became infected with Covid. Put another way, in just two months, about 1 out of every 20 vaccinated Israelis became infected with Sars-Cov-2.
Natural immunity - the protection following infection and recovery - lasts much longer, the study shows.
In fact, people who had already had Covid once had better protection from the virus more than a year later than people who had been vaccinated only three months before.
The gap was even larger in cases of severe infection.
Vaccinated people were more than five times as likely to develop severe infections than people with natural immunity. Only 25 out of roughly 300,000 Israelis with natural immunity developed severe Covid infections in the summer wave - compared to almost 1,400 vaccinated Israelis.
The difference did not result from gaps in age between vaccinated and recovered people. People over 60 benefitted even more from natural immunity relative to vaccination than did younger people.