Immunology & Infectious Diseases

If your newborn was ever started on intravenous antibiotics in the hospital — for a suspected infection, a confirmed bloodstream infection, or a urinary tract infection — you may have been told treatment would last anywhere from a few days to three weeks, often without a clear explanation of why…

For babies born very early, or living with ongoing heart or lung problems, a common winter virus called RSV can mean a trip to the hospital, and until recently, protecting them meant a shot every single month all season long. A major new study of nearly 1,000 babies found that a newer, single-shot…

Almost every baby born today to a mother living with HIV does not get the virus, which is one of the real triumphs of modern pregnancy care. Even so, doctors have wondered for years whether being exposed to HIV and to HIV medicines before birth leaves any lasting mark. Three studies published in…

The hepatitis B birth dose is a vaccine given in a baby's first day of life to stop a liver virus passing from mother to child. Four studies published in 2025 and 2026 show that babies who get it on time are infected far less often, that it appears safe even for babies born very early, that some…

Whooping cough came back strongly after the COVID-19 pandemic, and the babies hit hardest were only a few weeks old, too young for their own vaccines. New studies from Europe, the Gulf region and Asia show that when mothers are vaccinated during pregnancy, their newborns are far better protected…

Meningitis is an infection of the thin layers that wrap around the brain and spinal cord. Newborn babies catch it more often than people of any other age, and antibiotics usually clear the bacteria. The harder problem is the swelling and inflammation left behind, which can injure the brain even…

Echovirus 11 is a common virus that usually causes only mild illness, but in rare cases it can make a baby in the first weeks of life seriously ill. Four reports published in 2025, from Japan, Italy, China and Taiwan, explain how a newer strain has spread, how newborns catch it, what hospital care…

In many countries, the heel-prick blood test taken in a baby's first days now checks for a rare but serious immune condition called severe combined immunodeficiency, or SCID. Most babies who get an abnormal result turn out not to have SCID. Many of them do, however, have lower-than-usual numbers of…

A large clinical trial in a neonatal intensive care unit found that washing newborns once a day with an antiseptic skin wipe did not lower rates of serious bloodstream infection compared with washing with plain sterile water. Both approaches were equally safe, with mild, uncommon, and quickly…

Newborn conjunctivitis, an eye infection or irritation in a baby's first four weeks, is still common around the world, but the germs behind it differ from place to place. Three recent hospital studies from Singapore, India and Türkiye show what causes it today and which babies are more likely to be…

A new 15-year Japanese study followed 56 children born with congenital cytomegalovirus (CMV) to see how their hearing changed depending on whether they received antiviral medication as newborns. Treated children had smaller, earlier hearing declines that then stabilized, while untreated children…

Most babies born with toxoplasmosis look perfectly healthy, and the harm this parasite can do to the eyes and brain often appears only years later. Finding the infection early is what makes a year of treatment worth giving — yet two of the laboratory tests doctors relied on to find it were recently…