Background Despite the high efficacy of the BNT162b2 messenger RNA vaccine against
severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), rare breakthrough …

Here we compared SARS-CoV-2-specific antibody and T-cell responses between older
adults (> 80 years old, n= 51) and a younger control group (20–53 years old, n= 46) after …

Background The memory immune response is crucial for preventing reinfection or reducing
disease severity. However, the robustness and functionality of the humoral and T-cell …

To the Editor—On 4 August 2021, Tedros Adhanom Ghebreyesus, Director-General of the
World Health Organization, called for a global moratorium on booster doses of vaccination …

During the coronavirus disease-2019 (COVID-19) pandemic, severe acute respiratory
syndrome-related coronavirus-2 (SARS-CoV-2) has led to the infection of millions of people …

Results Among a total of 258,716 fully vaccinated persons, we identified 410 persons with
breakthrough infection and 14,465 controls. Median age (IQR) was 73 (68, 78) years for the …

Methods| A convenience sample of 3500 health care workers from the Johns Hopkins
Health System were enrolled starting June 2020 and followed up through September 3 …

Vaccine breakthrough SARS-CoV-2 infection has been monitored in 3720 healthcare
workers receiving 2 doses of BNT162b2. SARS-CoV-2 infection is detected in 33 subjects …

Background Breakthrough infections after SARS-CoV-2 vaccination have been reported.
Clinical outcomes in these persons are not widely known. Methods We evaluated all …

Obesity is associated with an increased risk of severe Coronavirus Disease 2019 (COVID-
19) infection and mortality. COVID-19 vaccines reduce the risk of serious COVID-19 …