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.
The study also showed that giving people who had natural immunity a vaccine dose did little to lower rates of infection for them, raising the question of why they should ever be vaccinated.
Finally, the study offered a disturbing signal that vaccination may ultimately interfere with the development of lasting immunity in people who are infected after being vaccinated.
A booster shot did lower the risk of infection about to the level of peak protection from natural immunity - but because the study ended in September, it is impossible to know how long that protection may last.
All these findings come out of a database of Covid infections among almost 6 million Israelis in August and September, at the peak of the fourth Covid wave in Israel. The database contains information on essentially every Israeli over age 16 who was fully vaccinated or had previously had a Covid infection.
The paper, “Protection and waning of natural and hybrid COVID-19 immunity,” is currently available as a preprint at: https://www.medrxiv.org/content/10.1101/2021.12.04.21267114v1.full.pdf
Oddly, the paper’s title does not mention waning of vaccine immunity, although the figures it presents make the severity of the problem clear. Such shyness is common among researchers presenting bad news about Covid vaccines - they will offer the data, but not highlight it.
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