Based on anti-HBs level ≥10 mIU/mL at 30 years and an 88% booster dose response, we estimate that ≥90% of participants had evidence of protection 30 years later. Booster doses are not needed.

vaccines are a critical tool for controlling the ongoing global pandemic. The Food and Drug Administration (FDA) has issued Emergency Use Authorizations for three COVID-19 vaccines for use in the United States.* In large, randomized-controlled trials, each vaccine was found to be safe and efficacious in preventing symptomatic, laboratoryconfirmed . Despite the high level of vaccine efficacy, a small percentage of fully vaccinated persons (i.e. received all recommended doses of an FDA-authorized COVID-19 vaccine) will develop symptomatic or asymptomatic infections with SARS-CoV-2, the virus that causes .CDC is working with state and territorial health departments to investigate SARS-CoV-2 infections among persons who are fully vaccinated and to monitor trends in case characteristics and SARS-CoV-2 variants identified from persons with these infections. For this surveillance, a vaccine breakthrough infection is defined as the detection of SARS-CoV-2 RNA or antigen in a respiratory specimen collected from a person ≥14 days after receipt of all recommended doses of an FDAauthorized COVID-19 vaccine. State health departments voluntarily report vaccine breakthrough infections to CDC. † When possible, genomic sequencing is performed on respiratory specimens that test positive for SARS-CoV-2 RNA (9). A total of 10,262 SARS-CoV-2 vaccine breakthrough infections had been reported from 46 U.S. states and territories as of April 30, 2021. Among these cases, 6,446 (63%) occurred in females, and the median patient age was 58 years (interquartile range = 40-74 years). Based on preliminary data, 2,725 (27%) vaccine breakthrough infections were asymptomatic, 995 (10%) patients were known to be hospitalized, and 160 (2%) patients died. Among the 995 hospitalized patients, 289 (29%) were asymptomatic or hospitalized for a reason unrelated to COVID-19. The median age of patients who died was 82 years (interquartile range = 71-89 years); 28 (18%) decedents were asymptomatic or died from a cause unrelated to COVID-19. Sequence data were available from 555 (5%) reported cases, 356 (64%) of which were identified as SARS-CoV-2 variants of

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There needs to be better awareness and education about travel-related illness and the importance of taking an adequate travel history.

Background and Aims The duration of protection from hepatitis B vaccination in children and adults is not known. In 1981, we used three doses of plasma‐derived hepatitis B vaccine to immunize a cohort of 1578 Alaska Native adults and children from 15 Alaska communities who were ≥6 months old. Approach and Results We tested persons for antibody to hepatitis B surface antigen (anti‐HBs) levels 35 years after receiving the primary series. Those with levels <10 mIU/ml received one booster dose of recombinant hepatitis B vaccine 2–4 weeks later and were then evaluated on the basis of anti‐HBs measurements 30 days postbooster. Among the 320 recruited, 112 persons had not participated in the 22‐ or 30‐year follow‐up study (group 1), and 208 persons had participated but were not given an HBV booster dose (group 2). Among the 112 persons in group 1 who responded to the original primary series, 53 (47.3%) had an anti‐HBs level ≥10 mIU/ml. Among group 1, 73.7% (28 of 38) of persons available for a booster dose responded to it with an anti‐HBs level ≥10 mIU/ml at 30 days. Initial anti‐HBs level after the primary series was correlated with higher anti‐HBs levels at 35 years. Among 8 persons who tested positive for antibody to hepatitis B core antigen, none tested positive for HBsAg or HBV DNA. Conclusions Based on anti‐HBs level ≥10 mIU/ml at 35 years and a 73.7% booster dose response, we estimate that 86% of participants had evidence of protection 35 years later. Booster doses are not needed in the general population at this time.