May 24, 2023

Antiviral Therapeutics and Vaccines

  • FDA voted in favor of approving the Abrysvo vaccine
    • Pfizer Inc. (NYSE: PFE) announced that the U.S. Food and Drug Administration’s (FDA) Vaccines and Related Biological Products Advisory Committee (VRBPAC) voted that the available data support the efficacy and safety of its unadjuvanted bivalent respiratory syncytial virus (RSV) prefusion F vaccine candidate RSVpreF or PF-06928316. The Committee voted 14 to 0 on effectiveness and 10 to 4 on safety. The vaccine candidate is currently under FDA review for the prevention of medically attended lower respiratory tract disease (MA-LRTD) and severe MA-LRTD caused by RSV in infants from birth up to six months of age by active immunization of pregnant individuals.
  • Safety of the BNT162b2 COVID-19 Vaccine in Children Aged 5 to 17 Years
    • This population-based study was conducted under a public health surveillance mandate from the US Food and Drug Administration. Participants aged 5 to 17 years were included if they received BNT162b2 COVID-19 vaccination through mid 2022 and had continuous enrollment in a medical health insurance plan from the start of an outcome-specific clean window until the COVID-19 vaccination. Surveillance of 20 prespecified health outcomes was conducted in near real time within a cohort of vaccinated individuals from the earliest Emergency Use Authorization date for the BNT162b2 vaccination (December 11, 2020) and was expanded as more pediatric age groups received authorization through May and June 2022. All 20 health outcomes were monitored descriptively, 13 of which additionally underwent sequential testing. For these 13 health outcomes, the increased risk of each outcome after vaccination was compared with a historical baseline with adjustments for repeated looks at the data as well as a claims processing delay. A sequential testing approach was used, which declared a safety signal when the log likelihood ratio comparing the observed rate ratio against the null hypothesis exceeded a critical value. Exposure was defined as receipt of a BNT162b2 COVID-19 vaccine dose. The primary analysis assessed primary series doses together (dose 1 + dose 2), and dose-specific secondary analyses were conducted. Follow-up time was censored for death, disenrollment, end of the outcome-specific risk window, end of the study period, or a receipt of a subsequent vaccine dose. Twenty prespecified health outcomes: 13 were assessed using sequential testing and 7 were monitored descriptively because of a lack of historical comparator data. This study included 3 017 352 enrollees aged 5 to 17 years. Of the enrollees across all 3 databases, 1 510 817 (50.1%) were males, 1 506 499 (49.9%) were females, and 2 867 436 (95.0%) lived in an urban area. In the primary sequential analyses, a safety signal was observed only for myocarditis or pericarditis after primary series vaccination with BNT162b2 in the age group 12 to 17 years across all 3 databases. No safety signals were observed for the 12 other outcomes assessed using sequential testing. Among 20 health outcomes that were monitored in near real time, a safety signal was identified for only myocarditis or pericarditis. Consistent with other published reports, these results provide additional evidence that COVID-19 vaccines are safe in children.
  • Statement on the antigen composition of COVID-19 vaccines
    • The WHO Technical Advisory Group on COVID-19 Vaccine Composition (TAG-CO-VAC) continues to meet regularly to assess the implications of SARS-CoV-2 evolution for COVID-19 vaccine antigen composition and advise WHO on whether changes are needed to the antigen composition of future COVID-19 vaccines. In April 2023, the TAG-CO-VAC indicated that the advisory group would convene at least twice in 2023: once in May 2023 and again, approximately 6 months later. At each meeting, recommendations to either maintain current vaccine composition or to consider updates will be issued. This frequency of evidence review by the TAG-CO-VAC is based on the kinetics of vaccine-derived immunity and the need for continued monitoring of the evolution of SARS-CoV-2, and will be adjusted if and as necessary. The TAG-CO-VAC met on 11-12 May 2023 to review the genetic and antigenic evolution of SARS-CoV-2, the performance of currently approved vaccines against circulating SARS-CoV-2 variants and the implications for COVID-19 vaccine antigen composition. The objective of an update to COVID-19 vaccine antigen composition is to enhance vaccine-induced immune responses to circulating SARS-CoV-2 variants. This statement and the recommendation for change is intended for all vaccine manufacturers and is intended to inform future formulations of COVID-19 vaccines.


  • Canine Olfactory Detection of SARS-CoV-2-Infected Humans
    • Coronavirus disease 2019 (COVID-19) developed into a pandemic within months. SARS-CoV-2 testing measures and vaccines became quickly accessible. However, due to pre- or asymptomatic transmission, effective disease control remains challenging. To complement conventional testing methods, scientists around the world have investigated dogs’ olfactory capability for true real-time detection. Several diseases are known to produce specific scents in affected individuals, excreted as volatile organic compounds, which can be easily detected by dogs within seconds. This systematic review evaluates the current evidence for using dogs’ olfactory system as a reliable COVID-19-screening tool. Two independent procedures for study quality assessment were used: the QUADAS-2 tool for the evaluation of laboratory tests’ diagnostic accuracy, designed for systematic reviews, and a second system for the general evaluation of canine scent detection studies, adapted with a focus on medical scent detection. Twenty-seven studies from thirteen countries were evaluated. Particular attention was paid to potential confounding factors, e.g., study design, patient/sample selection, dog characteristics, training protocols, and sample types/treatment. These analysis systems revealed that respectively four and six studies had low risk of bias and high quality. The four QUADAS-2 non-biased studies resulted in sensitivity and specificity ranges of 81–97% and 91–100%, whereas the six high quality studies according to the general evaluation system revealed sensitivity and specificity ranges of 82–97% and 83–100%, respectively. The other studies contained high risk of bias, concerns about the methodological applicability and/or quality concerns. Standardization and certification procedures as used for canine explosives detection should be established for medical scent detection dogs in order to use their undoubtful potential in an optimal and structured way. 


  • CDC HIV surveillance report
    • There was 36,000 new diagnoses of HIV in 2021. It is up from 2020 by 5,551 but down from 2017 by 2,655. Only about 20% of the new diagnoses in the new diagnosis in the US are in women. HIV is still predominantly impacting those with male-to-male contact but one third or 1 in every 3 new diagnosis is outside this population. The majority of new diagnosis are now occurring in the US South.


Situation Dashboards


World Health Organization (WHO)

Novel Coronavirus (COVID-19) Situation from World Health Organization (WHO)

Johns Hopkins University (JHU)

Coronavirus COVID-19 Global Cases by the Center for Systems Science and Engineering (CSSE) at JHU

COVID-19 in US and Canada

1Point3Acres Real-Time Coronavirus (COVID-19) Updates in US and Canada with Credible Sources

Genomic Epidemiology COVID-19

Genomic Epidemiology of (COVID-19) Maintained by the Nextstrain team, enabled by data from GISAID.

Sources for COVID-19 Information


World Health Organization (WHO)


Centers for Disease Control, US


International Society for Infectious Diseases


This Week in Virology (TWIV)

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