TY - JOUR AU - Kertes, Jennifer AU - Gez, Sharon Baruch AU - Saciuk, Yaki AU - Supino-Rosin, Lia AU - Stein, Naama Shamir AU - Mizrahi-Reuveni, Miri AU - Zohar, Anat T1 - Effectiveness of mRNA BNT162b2 Vaccine 6 Months after Vaccination among Patients in Large Health Maintenance Organization, Israel T2 - Emerging Infectious Disease journal PY - 2022 VL - 28 IS - 2 SP - 338 SN - 1080-6059 AB - Israel experienced a new wave of coronavirus disease during June 2021, six months after implementing a national vaccination campaign. We conducted 3 discrete analyses using data from a large health maintenance organization in Israel to determine whether IgG levels of fully vaccinated persons decrease over time, describe the relationship between IgG titer and subsequent PCR-confirmed infection, and compare PCR-confirmed infection rates by period of vaccination. Mean IgG levels steadily decreased over the 6-month period in the total tested population and in all age groups. An inverse relationship was found between IgG titer and subsequent PCR-positive infection. Persons vaccinated during the first 2 months of the campaign were more likely to become infected than those subsequently vaccinated. The vaccinated group >60 years of age had lower initial IgG levels and were at greater risk for infection. The findings support the decision to add a booster vaccine for persons >60 years of age. KW - COVID-19 KW - coronavirus disease KW - severe acute respiratory syndrome coronavirus 2 KW - SARS-CoV-2 KW - coronaviruses KW - viruses KW - respiratory infections KW - zoonoses KW - serologic tests KW - vaccines KW - mRNA BNT162b2 vaccine KW - vaccination KW - epidemiology KW - public health KW - infections KW - immune response KW - health maintenance organization KW - HMO KW - Israel DO - 10.3201/eid2802.211834 UR - https://wwwnc.cdc.gov/eid/article/28/2/21-1834_article ER - End of Reference