A new study in Israel found that the Pfizer vaccine was 85 percent effective after one shot, a finding that could lead some countries to delay the second shot in order to get more people vaccinated more quickly.The results echo research on the AstraZeneca vaccine, which has been shown to offer protection weeks after the first dose.A separate study published today suggested that the AstraZeneca vaccine was more effective when people received a second dose after three months, instead of six weeks.
The new findings lend ammunition to experts and governments, including that of Britain, which have advocated a “first dose first” strategy, which prioritizes giving as many people as possible an initial dose. But Dr. Fauci said that U.S. health officials were not willing to change their recommendations that all people receive two shots.
Pfizer and BioNTech also announced today that their vaccine can be stored at standard freezer temperatures for up to two weeks, rather than five days as recommended in their initial guidelines. Distribution of doses has been complicated by the requirement that the vaccines be stored at ultracold temperatures, and the change has the potential to expand the number of smaller pharmacies and doctors’ offices that can administer the vaccine.
Separately, new data from the Centers for Disease Control and Prevention found that the vaccines from Pfizer and BioNTech and Moderna were reassuringly safe and that side effects were rare. The agency examined nearly 14 million vaccinations and found nearly 7,000 reports of adverse events — including headaches, fatigue and muscle aches — and said that 91 percent of those cases were not serious.From Hopkins: Additional resources are available on our website.1. EMERGING VARIANTS A study published (preprint) by Harvard University examines the nasopharyngeal viral concentration in individuals infected with the B.1.1.7 SARS-CoV-2 variant… The researchers found that infection with the B.1.1.7 variant lasted significantly longer than for other variants, with a mean duration of infection of 13.3 days for the B.1.1.7 variant, compared to 8.2 days for non-B.1.1.7 variants. While the duration of infection was longer for the B.1.1.7 variant, the peak viral concentration was similar between B.1.1.7 and non-B.1.1.7 variants.”SARS-CoV-2 Positivity on or After 9 Days Among Quarantined Student Contacts of Confirmed Cases (In this study of a 9-day testing protocol for student contacts of confirmed COVID-19 cases in 1 Florida county, a reduction in loss of instructional time was found that was less than what would have occurred with 14-day quarantine. There was no evidence that an earlier return to school with a negative test result was linked with subsequent symptomatic illness. Had students returned to school before day 14 without testing on day 9 or thereafter, 8.2% of high school contacts would have returned to school with SARS-CoV-2 infection. These findings should be considered when evaluating the December 2020 CDC recommendation for a 10-day quarantine without testing or a 7-day quarantine with testing.Sequelae in Adults at 6 Months After COVID-19 Infection “In this cohort of individuals with COVID-19 who were followed up for as long as 9 months after illness, approximately 30% reported persistent symptoms. A unique aspect of our cohort is the high proportion of outpatients with mild disease…”(J. Harris: LONG HAULER ARTICLE, which includes many patients whose illness did not require hospitalization. A significant number of people were significantly improved by 9 months
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