Lessons from past influenza pandemics including the 1918/1919 Spanish Flu have shown that bacterial super infections causing disruptive lung pathology have been the major cause of mortality, rather than primary viral pneumonia.
Viruses causing respiratory illnesses like influenza, coronaviruses and measles damage the mucosa, the innermost lining of the respiratory tract abutting the airway lumen.
Thereafter, bacteria wreak havoc by colonising through the damaged mucosa. The most common bacteria causing these secondary damages include Streptococcus pneumoniae, Staphylococcus aureus and Haemophilus influenza.
In addition, Neisseria meningitidis may cause organ-based inflammation.
Histopathological examinations of the bronchial and lung tissues from pandemic influenza-affected patients have unequivocally demonstrated bacterial pneumonia as the major cause of mortality. This calls for immediate action for vaccination against the 23 strains of pneumococcus (Streptococcus pneumoniae).
With the global cataclysm due to the ongoing Sars-CoV-2 supercontagious infection, a highly thoughtful approach would be to offer vaccine protection to the community and nation.
The pneumococcal polysaccharide vaccine, marketed under the name Pneumovax23, is available in India. Furthermore, this vaccine may be administered to anyone including children above the age of two and adults, elderly and the severe elderly.
Many of these individuals would have the major co-morbidities including coronary artery disease, chronic heart failure, chronic kidney failure, chronic obstructive pulmonary disease, tuberculosis, diabetes mellitus, malnutrition, sickle cell disease, patients on immunosuppressive therapies including corticosteroids and biologics, chronic smokers, HIV-infected people with diminished CD4 counts, and even severely immunosuppressed patients including those undergoing chemotherapy and with immunedepleted states such as chronic variable immunodeficiency.
A question arises whether individuals merit seasonal flu-vaccination. Unlike in the West, the trend for seasonal flu-vaccination is much lower in countries like India. However, the vaccination against seasonal flu, which is also currently available in India as a quadrivalent vaccine against influenza A and B inactivated strains, shall be an additional prudent step. The chief reasons being that due to global travel, unimmunised individuals will bring back and import the common seasonal flu virus strains to the community.
The initial prodromal symptoms of Sars-CoV-2 and seasonal influenza overlap a lot, making it difficult to distinguish between specific viral illnesses. Pending lack of robust viral diagnostics, the only aggressive way is to mass immunise against seasonal flu.
Whether vaccination against seasonal flu would ramp up immunity against Sars-CoV-2 is currently unknown. However, the stimulation of innate immunity by inactivated influenza-based antigen will repose the immune system to a higher state of alertness to new Pathogen Associated Molecular Patterns associated with Sars-CoV-2.
The current pandemic is a justifiable social cause to overcome vaccination hesitancy and “anti-vax” hysteria and get these shots, which almost have only mild side effects and indolent course post-vaccination including mild soreness, redness or pain at the site, issues common with any vaccination.
The vaccination against bacterial pneumonia induces humoral antibodies in about two weeks.
These antibodies persist for a very long time, even years, and provide highly efficient immunity against the common forms of community-acquired and hospital acquired pneumonia. In the case of illnesses with specific respiratory
pathogens, antibiotic-based treatment should be initiated and continued irrespective of the vaccination status.
The first empiric antibiotic of choice should be the broad spectrum amoxicillin-clavulanate. Sars-CoV-2 and other influenza viruses are notorious for causing heart rhythm disturbances, also called cardiac arrhythmias. The antibiotic azithromycin, popular in managing upper and lower respiratory tract infections, is notorious for prolonging the QT interval on the ECG, enhancing the propensity for sudden cardiac arrest. Azithromycin has the potential to kill the patient much before the virus and should be avoided for treating acute and critical illnesses resulting from Sars-CoV-2.
There is striking similarity between the course of respiratory illness caused by Sars-CoV-2 or influenza with that of measles-associated pneumonia, another persistent cause of respiratory illness in children and adults worldwide.
Additional vaccination against measles and pertussis (whooping cough) is a highly important step in the overall management schemes of the current respiratory pandemic.
Sars-CoV-2 has a lot of overlap with the disease pathophysiology of Severe acute respiratory syndrome and Middle East respiratory syndrome pandemics. There is a constant tug of war between viral illnesses and interferon response mounted by the body.
One way of hijacking the immune system by Sars and Mers coronaviruses is to delay the interferon response. Thus, a rational pharmacological approach is to provide and administer interferons, medicines that are commonly used to treat hepatitis C (pegylated interferon). In fact, pegylated interferon and ribavirin were earlier used in the management of Mers patients.
Though zinc ionophore-based inhibition of RNA-dependent RNA polymerase by hydroxychloroquine is a rational basis for repurposing of this immunosuppressant drug usually used for treating rheumatoid arthritis and lupus, hydroxychloroquine not only prolongs QT interval but also causes dangerous ventricular arrhythmia, including Torsades de pointes.
Furthermore, hydroxychloroquine may cause severe hypoglycaemia, thus needing extreme caution in subjects with diabetes mellitus and calling for caution and medical supervision in the ad hoc administration of these medicines.
Vaccine protection using available injections against the common bacterial and viral illnesses, adequate hydration to maintain renal perfusion and electrolyte balance, organism specific antibiotics and broad spectrum antivirals like the neuraminidase inhibitor oseltamivir, shall all be cumulatively preventive and curative for primary and serious illnesses, and aid in aggressively preventing progression to critical illnesses from this currently circulating deadly virus.
Pneumococcal and seasonal flu vaccination not only prevents progression to dangerous pneumonia, but importantly contributes to prevention of heart failure and acute coronary syndromes. Added to these medical strategies are personal hygiene, maintenance of cough etiquette and frequent respiratory toilette including gargling and steam inhalation.
All these while we await the development of a seasonal Sars-CoV-2 vaccine.