A recent study led by Leumit Health Services and the Shamir Medical Center Institutional Review Board in Israel led to some concerning results. The study authors recently uploaded the manuscript to the preprint server medRxiv. Involving 33,943 fully vaccinated adults administered the Pfizer-BioNTech vaccine, three cohorts based on age were studied, including 1) 60 and up, 2) 40 to 59, and 3) 18 to 29. The study authors found concerning risk of breakthrough infection in those vaccinated at least 146 days (4.8 months) before reinfection—the risk further escalates for people older than 60.
A growing number of breakthrough cases now occur with the delta variant of interest. As the variant has a far greater viral surge, this could be why vaccinated individuals succumb to COVID-19 infection. Yahoo News reported that, according to a leaked CDC document, there were approximately 35,000 symptomatic COVID-19 infections per week among the fully vaccinated, but this needs to be confirmed.
Although most vaccinated cases don’t lead to severe cases, a growing trend in Israel reveals vaccinated people are at ever greater risks. To date, about 50% of America’s population is fully vaccinated based on CDC data. These vaccinations, however, were developed to deal with different strains of the pathogen. What about the highly transmissible and virulent delta variant or lambda?
The Israeli Study
Leumit Health Services and the Shamir Medical Center Institutional Review Board in Israel led a study involving 33,943 vaccinated adults who received the Pfizer-BioNTech vaccine known as BNT162b2. Segmenting the patients into the three age cohorts mentioned above, the team found the overall breakthrough infection rate rare at 1.8%; however, they found risk markedly rises with age and duration from the last vaccine dose. In fact, those participants over 60 who had received their last vaccine over five months ago faced treble risks of breakthrough infections.
Yahoo News reports that even Pfizer’s CEO Albert Bourla agrees that vaccine effectiveness wanes with time. For example, he concurred in July that the vaccine efficacy lowers to 84% after four to six months. Yahoo also reported a Pfizer-sponsored study indicating the vaccine was most potent from one week to two months from the second jab. The BNT162b2 product then declines in efficacy on average about 6% every two months.
That’s why the chatter is now all about booster doses as the Pfizer CEO recently declared on CNBC’s Exchange, “The good news is that we are very, very confident that a third dose, a booster, will take up the immune response to levels that will be enough to protect against the delta variant.”
That’s why the CDC recently recommended vaccinated people wear masks, even at home if there is an unvaccinated person or someone immunocompromised living there.
About Leumit Health Services
An Israeli health insurance and medical services organization founded in 1933, Leumit Health Services was the smallest of the four Kupot Holim (Israel’s state-mandated health funds) with 700,000 members.
Ariel Israel, MD, Ph.D., Leumit Research Institute & Department of Family Medicines, Leumit Health Services, Israel.