Israel was the first country to begin mass rollout of Pfizer-BioNTech COVID-19 vaccine. It has also conducted several studies on the efficacy of this vaccine. A recent real time study found that those who had recovered from a natural bout of COVID-19 during the early waves of the pandemic seemed to have a lower risk of getting infected with the delta variant when compared with those who took a Pfizer-BioNTech vaccine.
The largest real world analysis conducted in Israel also showed that reinfections were less common among those who had gained natural immunity from a COVID-19 infection. This research is different from earlier ones that showed that immunizations gave better protection than an earlier infection. However, those studies were not conducted on the delta variant. The delta variant gained prominence in recent months when this new study was conducted.
The researchers said that their analysis demonstrated that natural immunity gives “longer lasting and stronger protection” against the delta variant in terms of infection, symptomatic disease as well as hospitalizations.
They also concluded that a single shot of the vaccine boosted the protection of those who had been naturally infected. The booster shots have recently been rolled out in Israel, so the long term effects of this shot are currently unknown.
The researchers analyzed the medical records of tens of thousands of Israelis. They examined their infections, symptoms as well as hospitalizations from June 1 to August 14, when the delta variant was prevalent in the nation. They posted the results on medRxiv.
Peers, who have reviewed it, say that the study highlights the benefits of natural immunity but has not considered “what this virus does to the body to get to that point” according to Marion Pepper, who is an immunologist at the University of Washington in Seattle.
Vaccines are a good shield against serious disease. Although natural immunity appears to last longer, it is still a fact that unvaccinated people have been getting infected more seriously and are hospitalized more often in much larger numbers after the surge of the delta variant when compared with the vaccinated who get infected as breakthrough cases.
One conclusion from this study indicates that those who have been infected with COVID-19 and have gained natural immunity might need only one dose of a COVID-19 vaccine to increase immunity.