New 2023-2024 formulations of the mRNA COVID-19 vaccines manufactured by Pfizer/BioNTech (Comirnaty) and that more closely target currently circulating variants have been licensed by the FDA for use in persons ≥12 years old and made available under FDA Emergency Use Authorizations (EUAs) for use in persons 6 months to 11 years old. The bivalent (original and Omicron BA.4/5) formulations of the Pfizer and Moderna vaccines are no longer authorized for use in the US.

Two recombinant vaccines, Arexvy (GSK) and Abrysvo (Pfizer), have been approved by the FDA for prevention of lower respiratory tract disease (LRTD) caused by respiratory syncytial virus (RSV) in adults ≥60 years old. They are the first RSV vaccines to be approved in the US. Abrysvo is also approved for use in pregnant women at 32-36 weeks' gestation to prevent LRTD caused by RSV in their infants from birth through 6 months of age.

The FDA has approved nirsevimab-alip (Beyfortus – AstraZeneca/Sanofi), a long-acting monoclonal antibody, for the prevention of respiratory syncytial virus (RSV) lower respiratory tract disease in neonates and infants born during or entering their first RSV season, and in children ≤24 months old who are at increased risk for severe RSV disease through their second RSV season. Nirsevimab is the first drug to be approved for protection of all infants during their first RSV season.

The drugs of choice for treatment of viral infections (other than HIV) and their dosages are listed in Tables 1-6 on the pages that follow. Some of the indications and dosages recommended here have not been approved by the FDA. Vaccines used for the prevention of viral infections are discussed elsewhere.

The drugs of choice for treatment of non-HIV viral infections and their dosages are listed in Tables 1-6 on the pages that follow. Some of the indications and dosages recommended here have not been approved by the FDA. Vaccines used for the prevention of viral infections are discussed in another issue of Treatment Guidelines.

The drugs of choice for treatment of non-HIV viral infections with their dosages and cost are listed in Tables 1-6. Some of the indications and dosages recommended here have not been approved by the FDA. Vaccines used in the prevention of viral infections are discussed in the "Adult Immunization" issue of Treatment Guidelines.

The drugs of choice for non-HIV viral infections with their dosages and cost are listed in the tables that begin on page 24. Some of the indications and dosages recommended here have not been approved by the FDA.

The choice of drugs for treatment of pneumonia depends on the most likely pathogens causing the infection and local antimicrobial resistance patterns. Factors such as severity of illness, presence of co-morbid conditions and whether the infection is community or hospital-acquired also need to be considered.

The drugs of choice for non-HIV viral infections with their dosages and cost are listed in the table that begins on the next page. Since the last Medical Letter issue on this subject, some new drugs and some new recommendations for old drugs have been added.

Palivizumab (Synagis - MedImmune), an injectable monoclonal antibody, has been marketed in the USA since 1999 for prevention of respiratory syncytial virus (RSV) disease in high-risk infants and children.

The drugs of choice for non-HIV viral infections with their dosages and cost are listed in the [article's] table.

The drugs of choice for non-HIV viral infections with their dosages and cost are listed in the table on the next page. The treatment of HIV infection will be discussed in a future issue.