Waning Immunity from Pfizer’s Covid-19 Vaccine


In the Washington Post, Andrew Jeong writes referring to results of a recent study that ‘antibodies against the coronavirus among vaccinated people fell briskly up to 80 days after receiving the second dose, while the pace of decline slowed thereafter’.

According to study published in the New England Journal of Medicine (NEJM), peoples ages 18 to 45 had stronger immunity than those over 65 after receiving their second shot. The study conducted in Israel during December to July with more than 4,800 vaccinated health-care professionals.

Particularly vulnerable populations … were older men and participants with immunosuppression.

Study authors of the Israel study (source: The Washington Post)

Sheba’s Dr. Gili Regev-Yochay and colleagues wrote “We conducted this prospective longitudinal cohort study involving health care workers at Sheba Medical Center, a large tertiary medical center in Israel”.

The study authors added “Published work about many vaccines, such as those against measles, mumps, and rubella, has shown a small decrease each year of 5 to 10% in the neutralizing antibody levels. We found that a significant and rapid decrease in humoral response to the BNT162b2 vaccine was observed within months after vaccination.”

“Overall, the accumulating evidence from our study and others shows that long-term humoral response and vaccine effectiveness in previously infected persons were superior to that in recipients of two doses of vaccine”.

The other study from Qatar which was also published in the NEJM only 2-days before reportedly looked actual infections among the highly vaccinated population of that small Gulf nation, who had received ‘Pfizer/BioNTech’s vaccine, also known as BNT162b2’.

“BNT162b2-induced protection against infection builds rapidly after the first dose, peaks in the first month after the second dose, and then gradually wanes in subsequent months. The waning appears to accelerate after the fourth month, to reach a low level of approximately 20% in subsequent months,” Laith Abu-Raddad of Weill Cornell Medicine-Qatar and colleagues wrote.

These findings suggest that a large proportion of the vaccinated population could lose its protection against infection in the coming months, perhaps increasing the potential for new epidemic waves.

Laith Abu-Raddad and colleagues (source: CNN Health)

CNN Health writes that the US Centers for Disease Control and Prevention (CDC) has recommended “people older than 65, people with conditions making them more susceptible to getting seriously ill with breakthrough infections, and people at high risk of infection such as health care workers and prison inmates get boosters”.

Coronavirus-19 vaccination watch

According to the US Centers for Disease Control and Prevention (CDC) COVID vaccination tracker page (as of October 8, 9 a.m.) 485,713,525 doses have been distributed and 400,669,422 doses administered. According MDH COVID-19 Response vaccine data (as of October 6) a total of 6,569,914 doses of Covid-19 (Pfizer & Moderna) vaccines have been administered in Minnesota. According to the MDH latest tally (as of October 8) the confirmed COVID-19 cases in Minnesota are 735,646 (out of 12,855,286 tested) with 8,295 deaths.