ABSTRACT
Two conundrums puzzle COVID-19 investigators: 1) morbidity and mortality is rare among infants and young children and 2) rates of morbidity and mortality exhibit large variances across nations, locales, and even within cities. It is found that the higher the rate of pneumococcal vaccination in a nation (or city) the lower the COVID-19 morbidity and mortality. Vaccination rates with Bacillus Calmette-Guerin, poliovirus, and other vaccines do not correlate with COVID-19 risks, nor do COVID-19 case or death rates correlate with number of people in the population with diabetes, obesity, or adults over 65. Infant protection may be due to maternal antibodies and antiviral proteins in milk such as lactoferrin that are known to protect against coronavirus infections. Subsequent protection might then be conferred (and correlate with) rates of Haemophilus influenzae type B (Hib) (universal in infants) and pneumococcal vaccination, the latter varying widely by geography among infants, at-risk adults, and the elderly. Also see the video abstract here https://youtu.be/GODBYRbPL00.
Subject(s)
Coronavirus Infections/mortality , Coronavirus Infections/pathology , Lactoferrin/physiology , Pneumococcal Vaccines/pharmacology , Pneumonia, Viral/mortality , Pneumonia, Viral/pathology , Vaccination/statistics & numerical data , Adolescent , Adult , Age Factors , Aged , Aged, 80 and over , Betacoronavirus/physiology , COVID-19 , Child , Child, Preschool , Coronavirus Infections/epidemiology , Female , Geography , Haemophilus influenzae type b/immunology , Humans , Infant , Infant Mortality , Infant, Newborn , Lactoferrin/blood , Male , Middle Aged , Mortality , Pandemics , Pneumonia, Viral/epidemiology , SARS-CoV-2 , Severity of Illness Index , Vaccination Coverage/statistics & numerical data , Young AdultABSTRACT
Lactoferrin is a nutrient classically found in mammalian milk. It binds iron and is transferred via a variety of receptors into and between cells, serum, bile, and cerebrospinal fluid. It has important immunological properties, and is both antibacterial and antiviral. In particular, there is evidence that it can bind to at least some of the receptors used by coronaviruses and thereby block their entry. Of importance are Heparan Sulfate Proteoglycans (HSPGs) and the host receptor angiotensin-converting enzyme 2 (ACE2), as based on other activities lactoferrin might prevent severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) from attaching to the host cells. Lactoferrin (and more specifically enteric-coated LF because of increased bioavailability) may consequently be of preventive and therapeutic value during the present COVID-19 pandemic.